The Project Gutenberg EBook of Surgical Anatomy, by Joseph Maclise
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Title: Surgical Anatomy
Author: Joseph Maclise
Release Date: January 27, 2008 [EBook #24440]
Language: English
Character set encoding: ASCII
*** START OF THIS PROJECT GUTENBERG EBOOK SURGICAL ANATOMY ***
Produced by Don Kostuch
[Transcriber's Notes]
Thanks to Carol Presher of Timeless Antiques, Valley, Alabama, for
lending the original book for this production. The 140 year old binding
had disintegrated, but the paper and printing was in amazingly good
condition, particularly the multicolor images.
Thanks also to the Mayo Clinic. This book has increased my appreciation
of their skilled care of my case by showing the many ways that things
could go wrong.
Footnotes are indicated by "[Footnote]" where they appear in the text.
The body of the footnote appears immediately following the complete
paragraph. If more than one footnote appears in the same paragraph, they
are numbered.
A few obvious misspellings have been corrected. Several cases of
alternate spelling of the same(?) word have not been modified.
Pages have been reorganized to avoid splitting sentences and paragraphs.
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Here are the definitions of some words used in the text. Medical terms
are defined only relating to humans. Words are omitted that have
ambiguous or technical meanings not expressible in lay language.
acromial (acromion)
Outward end of the spine of the scapula or shoulder blade.
adipose
Consisting of, resembling, or relating to fat.
anasarca
Pronounced, generalized edema; accumulation of serous fluid in various
tissues and cavities of the body.
anastomosing (anastomoses, anastomosis)
Communication between blood vessels by means of collateral channels,
when usual routes are obstructed. Opening between two organs or spaces
that normally are not connected.
aneurism
Localized blood-filled dilatation of a blood vessel caused by disease
or weakening of the vessel's wall.
anthropotomist (anthropotomy)
One versed in human anatomy.
aorta (aortic)
Main trunk of the arterial system, conveying blood from the left
ventricle of the heart to all of the body except the lungs.
apices (plural of apex)
Pointed end of an object; the tip.
aponeurosis
Sheet-like fibrous membrane, resembling a flattened tendon, that
serves as a fascia to bind muscles together or as a means of
connecting muscle to bone.
armamentaria
Complete equipment of a physician or medical institution, including
books, supplies, and instruments.
auscultation
Listening, either directly or through a stethoscope or other
instrument, to sounds within the body as a method of diagnosis.
axilla (axillary)
Armpit.
azygos
Occurring singly; not one of a pair.
bifid
Separated or cleft into two equal parts or lobes.
biliary
Relating to bile, the bile ducts, or the gallbladder; transporting
bile.
bistoury
Long, narrow surgical knife for minor incisions.
bougie
Slender, flexible instrument introduced into body passages, to dilate,
examine, or medicate.
brachial (brachio)
Belonging to the arm.
bubonocele
Inguinal hernia, in which the protrusion of the intestine is limited
to the region of the groin.
cannula
Metal tube for insertion into the body to draw off fluid or to
introduce medication.
carotid
Two large arteries, one on each side of the head.
cephalic
Relating to the head.
cervical
Pertaining to the neck.
chlorotic
Benign iron-deficiency anemia in adolescent girls, marked by a pale
yellow-green complexion.
clavicle
Either of two slender bones extending from the upper part of the
sternum (breastbone) to the shoulder.
coaptation
Joining together of two surfaces, such as the edges of a wound or the
ends of a broken bone.
condyle
Smooth surface area at the end of a bone, forming part of a joint.
costal
Pertaining to the ribs or the upper sides of the body.
cremaster
Suspensory muscle of the testis.
crural
Relating to the leg or thigh.
director
A smoothly grooved instrument used with a knife to limit the incision
of tissues.
distal
Situated away from the point of origin or attachment.
dropsy (dropsical) (edema)
Swelling from excessive accumulation of watery fluid in cells,
tissues, or serous cavities
emphysema
Chronic, irreversible disease of the lungs; abnormal enlargement of
air spaces in the lungs accompanied by destruction of the tissue
lining the walls of the air spaces.
emunctory
Organ or duct that removes or carries waste from the body.
epigastric (epigastrium)
Upper middle region of the abdomen.
episternal
See sternum.
esophagus
See oesophagus.
euphoneously (euphoniously)
Pleasant in sound; agreeable to the ear;
exigence
Urgency, need, demand, or requirement intrinsic to a circumstance.
extravasation
Exuding or passing out of a vessel into surrounding tissues; said of
blood, lymph or urine
fascia
A band of connective tissue supporting, or binding together internal
organs or parts of the body.
femoral
Pertaining to, or situated at, in, or near the thigh or femur.
fistula
Abnormal duct or passage resulting from injury, disease, or a
congenital disorder that connects an abscess, cavity, or hollow organ
to the body surface or to another hollow organ.
foramen (foramina)
Opening, orifice, or short passage, as in a bone.
fossa (fossae)
Small cavity or depression, as in a bone.
hepatic
Pertaining to the liver.
herniae (hernia)
Protrusion of an organ or tissue through an opening in its surrounding
walls, especially in the abdomen.
humerus
Bone in the arm of humans extending from the shoulder to the elbow.
hydragogue
Cathartics that aid in the removal of edematous fluids and thus
promote the discharge of watery fluid from the bowels.
hydrocele
An accumulation of serous fluid, usually about the testis.
hydrops
See dropsy. Edema.
iliac artery
Common iliac artery--either of two large arteries that conduct blood
to the pelvis and the legs. External iliac artery--the outer branch of
an iliac artery that becomes the femoral artery. Hypogastric
artery--internal iliac artery; the inner branch of an iliac artery
that conducts blood to the gluteal region.
infundibuliform
Shaped like a funnel.
inguinal
Relating to, or located in the groin.
innominate
Designated parts otherwise unnamed; as, the innominate artery, a great
branch of the arch of the aorta; the innominate vein, a great branch
of the superior vena cava.
inosculate
Unite by openings; connect or join so as to become or make continuous,
as fibers; blend, unite intimately
integument
Natural covering, coating, enclosure, etc., as a skin, shell, or rind.
laryngotomy
Cutting into the larynx, from the outside of the neck, to assist
respiration, or to remove foreign bodies.
ligature
Thread or wire for constriction of blood vessels or for removing
tumors by strangulation.
lithotomy
Surgery to remove one or more stones from an organ or duct.
meatus
Body opening such as the opening of the ear or the urethral canal.
metamorphosis
Profound change in form from one stage to the next, as from the
caterpillar to the pupa and from the pupa to the adult butterfly.
micturition
Passing urine; urination.
nares (naris)
Nostrils or the nasal passages.
nisus
Effort or endeavor to realize an aim.
occiput
Back part of the head or skull.
oesophagus (esophagus)
Muscular membranous tube for the passage of food from the pharynx to
the stomach.
osseous
Bone, bony;
palmar
Pertaining to, or located in the palm of the hand.
paracentesis
Puncture of the wall of a cavity to drain off fluid.
parietes
Wall of a body part, organ, or cavity.
parotid
Salivary gland situated at the base of each ear; near the ear.
percussion
Striking or tapping the surface the body for diagnostic or therapeutic
purposes.
pericardii (pericardium)
A double membranous sac protecting the heart. The layer in contact
with the heart is referred to as the visceral layer, the outer layer
in contact with surrounding organs is the parietal pericardium.
peritoneum (peritonaeum)
Serous membrane that lines the walls of the abdominal cavity and folds
inward to enclose the viscera.
pharynx (pharyngeal)
The cavity, with its surrounding membrane and muscles, that connects
the mouth and nasal passages with the esophagus.
physiology (physiologist)
Biological study of the functions of living organisms and their parts.
platysma
Broad, thin muscle on each side of the neck, from the upper part of
the shoulder to the corner of the mouth. They wrinkle the skin of the
neck and depresses the corner of the mouth.
pleura
Thin serous membrane in mammals that envelops each lung and folds back
to make a lining for the chest cavity.
pleuritic (pleurisy)
Inflammation of the pleura, often as a complication of a disease such
as pneumonia, accompanied by accumulation of fluid in the pleural
cavity, chills, fever, and painful breathing and coughing.
plexus
Network, as of nerves or blood vessels.
pneumothorax
Air or gas in the pleural cavity.
popliteal
Relating to the hollow part of the leg behind the knee joint.
probang
Long, slender, elastic rod with a sponge at the end. It is introduced
into the esophagus or larynx to remove foreign bodies or introduce
medication.
pudic
Pertaining to the external organs of generation.
pyriform
Shaped like a pear.
radius
Bone of the forearm on the thumb side. (See ulnar)
ramus
A branch, as of a nerve, or blood vessel.
raphe
Seamlike union between two parts or halves of an organ.
ratiocination
Logical reasoning.
sacculated
Formed with or having saclike expansions.
scirrhus
Hard dense cancerous growth usually arising from connective tissue.
septa
Thin partition dividing two cavities or soft masses of tissue.
sternum
Bones extending along the middle line of the ventral portion of the
body of most vertebrates, consisting in humans of a flat, narrow bone
connected with the clavicles and the true ribs; breastbone.
stricture
Abnormal narrowing of a duct or passage.
subclavian
Beneath the clavicle.
submaxillary
Pertaining to the lower jaw.
sui generis
The only example of its kind; a class of its own; unique
superficies
Outward appearance.
sutural
Junction of two bones.
symphysis
Growing together, or the fixed or nearly fixed union, of bones.
taxis
Replacing of a displaced part, or the reducing of a hernia, by
manipulation without cutting.
tegument (tegumentary, integument)
Natural outer covering.
thorax (thoracic)
Trunk between the neck and the abdomen, containing the cavity enclosed
by the ribs, sternum, and certain vertebrae, containing the heart,
lungs, etc.; chest.
trachea (tracheal)
Tube descending from the larynx to the bronchi and carrying air to the
lungs. Windpipe.
trephine (trephining)
Small circular saw with a center pin mounted on a strong hollow metal
shaft, used to remove circular disks of bone from the skull.
trocar
Sharp-pointed instrument enclosed in a cannula, used for withdrawing
fluid from a cavity, as the abdominal cavity.
tunica vaginalis
Pouch of serous membrane covering the testis and derived from the
peritoneum.
venesection (venisection, phlebotomy)
Opening a vein by incision or puncture to remove blood as a
therapeutic treatment.
viz.
Contraction of the Latin "videre licet" meaning "it is permissible to
see," The -z- is not a letter, but originally a twirl, representing
the symbol for the ending -et. Usually read as "namely."
ulnar
Bone of the forearm on the side opposite to the thumb. (See radius)
[End Transcriber's Notes]
SURGICAL ANATOMY
BY
JOSEPH MACLISE
FELLOW OF THE ROYAL COLLEGE OF SURGEONS.
WITH SIXTY-EIGHT COLOURED PLATES.
PHILADELPHIA:
BLANCHARD AND LEA.
1859.
[Stamped by owner: John D. Warren, Physician & Surgeon.]
I INSCRIBE THIS WORK TO THE GENTLEMEN
WITH WHOM AS A FELLOW-STUDENT I WAS ASSOCIATED AT THE
London University College:
AND IN AN ESPECIAL MANNER, IN THEIR NAME AS WELL AS MY OWN,
I AVAIL MYSELF OF THE OPPORTUNITY TO RECORD, ON THIS PAGE,
ALBEIT IN CHARACTERS LESS IMPRESSIVE THAN THOSE WHICH ARE
WRITTEN ON THE LIVING TABLET OF MEMORY,
THE DEBT OF GRATITUDE WHICH WE OWE TO THE LATE
SAMUEL COOPER, F.R.S., AND ROBERT LISTON, F.R.S.,
TWO AMONG THE MANY DISTINGUISHED PROFESSORS OF THAT
INSTITUTION, WHOSE PUPILS WE HAVE BEEN,
AND FROM WHOM WE INHERIT THAT BETTER POSSESSION THAN LIFE
ITSELF, AN ASPIRATION FOR THE LIGHT OF SCIENCE.
JOSEPH MACLISE.
PREFACE.
The object of this work is to present to the student of medicine and the
practitioner removed from the schools, a series of dissections
demonstrative of the relative anatomy of the principal regions of the
human body. Whatever title may most fittingly apply to a work with this
intent, whether it had better be styled surgical or medical, regional,
relative, descriptive, or topographical anatomy, will matter little,
provided its more salient or prominent character be manifested in its
own form and feature. The work, as I have designed it, will itself show
that my intent has been to base the practical upon the anatomical, and
to unite these wherever a mutual dependence was apparent.
That department of anatomical research to which the name topographical
strictly applies, as confining itself to the mere account of the form
and relative location of the several organs comprising the animal body,
is almost wholly isolated from the main questions of physiological and
transcendental interest, and cannot, therefore, be supposed to speak in
those comprehensive views which anatomy, taken in its widest
signification as a science, necessarily includes. While the anatomist
contents himself with describing the form and position of organs as they
appear exposed, layer after layer, by his dissecting instruments, he
does not pretend to soar any higher in the region of science than the
humble level of other mechanical arts, which merely appreciate the
fitting arrangement of things relative to one another, and combinative
to the whole design of the form or machine of whatever species this may
be, whether organic or inorganic. The descriptive anatomist of the human
body aims at no higher walk in science than this, and hence his
nomenclature is, as it is, a barbarous jargon of words, barren of all
truthful signification, inconsonant with nature, and blindly
irrespective of the cognitio certa ex principiis certis exorta.
Still, however, this anatomy of form, although so much requiring
purification of its nomenclature, in order to clothe it in the high
reaching dignity of a science, does not disturb the medical or surgical
practitioner, so far as their wants are concerned. Although it may, and
actually does, trammel the votary who aspires to the higher
generalizations and the development of a law of formation, yet, as this
is not the object of the surgical anatomist, the nomenclature, such as
it is, will answer conveniently enough the present purpose.
The anatomy of the human form, contemplated in reference to that of all
other species of animals to which it bears comparison, constitutes the
study of the comparative anatomist, and, as such, establishes the
science in its full intent. But the anatomy of the human figure,
considered as a species, per se, is confessedly the humblest walk of the
understanding in a subject which, as anatomy, is relationary, and
branches far and wide through all the domain of an animal kingdom. While
restricted to the study of the isolated human species, the cramped
judgment wastes in such narrow confine; whereas, in the expansive gaze
over all allying and allied species, the intellect bodies forth to its
vision the full appointed form of natural majesty; and after having
experienced the manifold analogies and differentials of the many, is
thereby enabled, when it returns to the study of the one, to view this
one of human type under manifold points of interest, to the appreciation
of which the understanding never wakens otherwise. If it did not happen
that the study of the human form (confined to itself) had some practical
bearing, such study could not deserve the name of anatomical, while
anatomical means comparative, and whilst comparison implies inductive
reasoning.
However, practical anatomy, such as it is, is concerned with an exact
knowledge of the relationship of organs as they stand in reference to
each other, and to the whole design of which these organs are the
integral parts. The figure, the capacity, and the contents of the
thoracic and abdominal cavities, become a study of not more urgent
concernment to the physician, than are the regions named cervical,
axillary, inguinal, &c., to the surgeon. He who would combine both modes
of a relationary practice, such as that of medicine and surgery, should
be well acquainted with the form and structures characteristic of all
regions of the human body; and it may be doubted whether he who pursues
either mode of practice, wholly exclusive of the other, can do so with
honest purpose and large range of understanding, if he be not equally
well acquainted with the subject matter of both. It is, in fact, more
triflingly fashionable than soundly reasonable, to seek to define the
line of demarcation between the special callings of medicine and
surgery, for it will ever be as vain an endeavour to separate the one
from the other without extinguishing the vitality of both, as it would
be to sunder the trunk from the head, and give to each a separate living
existence. The necessary division of labour is the only reason that can
be advanced in excuse of specialisms; but it will be readily agreed to,
that that practitioner who has first laid within himself the foundation
of a general knowledge of matters relationary to his subject, will
always be found to pursue the speciality according to the light of
reason and science.
Anatomy--the [Greek words], the knowledge based on principle--is the
foundation of the curative art, cultivated as a science in all its
branchings; and comparison is the nurse of reason, which we are fain to
make our guide in bringing the practical to bear productively. The human
body, in a state of health, is the standard whereunto we compare the
same body in a state of disease. The knowledge of the latter can only
exist by the knowledge of the former, and by the comparison of both.
Comparison may be fairly termed the pioneer to all certain knowledge. It
is a potent instrument--the only one, in the hands of the pathologist,
as well as in those of the philosophic generalizer of anatomical facts,
gathered through the extended survey of an animal kingdom. We best
recognise the condition of a dislocated joint after we have become well
acquainted with the contour of its normal state; all abnormal conditions
are best understood by a knowledge of what we know to be normal
character. Every anatomist is a comparer, in a greater or lesser degree;
and he is the greatest anatomist who compares the most generally.
Impressed with this belief, I have laid particular emphasis on imitating
the character of the normal form of the human figure, taken as a whole;
that of its several regions as parts of this whole, and that of the
various organs (contained within those regions) as its integrals or
elements. And in order to present this subject of relative anatomy in
more vivid reality to the understanding of the student, I have chosen
the medium of illustrating by figure rather than by that of written
language, which latter, taken alone, is almost impotent in a study of
this nature.
It is wholly impossible for anyone to describe form in words without the
aid of figures. Even the mathematical strength of Euclid would avail
nothing, if shorn of his diagrams. The professorial robe is impotent
without its diagrams. Anatomy being a science existing by demonstration,
(for as much as form in its actuality is the language of nature,) must
be discoursed of by the instrumentality of figure.
An anatomical illustration enters the understanding straight-forward in
a direct passage, and is almost independent of the aid of written
language. A picture of form is a proposition which solves itself. It is
an axiom encompassed in a frame-work of self-evident truth. The best
substitute for Nature herself, upon which to teach the knowledge of her,
is an exact representation of her form.
Every surgical anatomist will (if he examine himself) perceive that,
previously to undertaking the performance of an operation upon the
living body, he stands reassured and self-reliant in that degree in
which he is capable of conjuring up before his mental vision a distinct
picture of his subject. Mr. Liston could draw the same anatomical
picture mentally which Sir Charles Bell's handicraft could draw in
reality of form and figure. Scarpa was his own draughtsman.
If there may be any novelty now-a-days possible to be recognised upon
the out-trodden track of human relative anatomy, it can only be in
truthful and well-planned illustration. Under this view alone may the
anatomist plead an excuse for reiterating a theme which the beautiful
works of Cowper, Haller, Hunter, Scarpa, Soemmering, and others, have
dealt out so respectably. Except the human anatomist turns now to what
he terms the practical ends of his study, and marshals his little
knowledge to bear upon those ends, one may proclaim anthropotomy to have
worn itself out. Dissection can do no more, except to repeat
Cruveilhier. And that which Cruveilhier has done for human anatomy,
Muller has completed for the physiological interpretation of human
anatomy; Burdach has philosophised, and Magendie has experimented to the
full upon this theme, so far as it would permit. All have pushed the
subject to its furthest limits, in one aspect of view. The narrow circle
is footworn. All the needful facts are long since gathered, sown, and
known. We have been seekers after those facts from the days of
Aristotle. Are we to put off the day of attempting interpretation for
three thousand years more, to allow the human physiologist time to slice
the brain into more delicate atoms than he has done hitherto, in order
to coin more names, and swell the dictionary? No! The work must now be
retrospective, if we would render true knowledge progressive. It is not
a list of new and disjointed facts that Science at present thirsts for;
but she is impressed with the conviction that her wants can alone be
supplied by the creation of a new and truthful theory,--a generalization
which the facts already known are sufficient to supply, if they were
well ordered according to their natural relationship and mutual
dependence. "Le temps viendra peut-etre," says Fontenelle, "que l'on
joindra en un corps regulier ces membres epars; et, s'ils sont tels
qu'on le souhaite, ils s'assembleront en quelque sorte d'eux-memes.
Plusieurs verites separees, des qu'elles sont en assez grand nombre,
offrent si vivement a l'esprit leurs rapports et leur mutuelle
dependance, qu'il semble qu'apres les avoir detachees par une espece de
violence les unes des autres, elles cherchent naturellement a se
reunir."--(Preface sur l'utilite des Sciences, &c.)
The comparison of facts already known must henceforward be the scalpel
which we are to take in hand. We must return by the same road on which
we set out, and reexamine the things and phenomena which, as novices, we
passed by too lightly. The travelled experience may now sit down and
contemplate.
That which I have said and proved elsewhere in respect to the skeleton
system may, with equal truth, be remarked of the nervous system--namely,
that the question is not in how far does the limit of diversity extend
through the condition of an evidently common analogy, but by what rule
or law the uniform ens is rendered the diverse entity? The womb of
anatomical science is pregnant of the true interpretation of the law of
unity in variety; but the question is of longer duration than was the
life of the progenitor. Though Aristotle and Linnaeus, and Buffon and
Cuvier, and Geoffroy St. Hilaire and Leibnitz, and Gothe, have lived and
spoken, yet the present state of knowledge proclaims the Newton of
physiology to be as yet unborn. The iron scalpel has already made
acquaintance with not only the greater parts, but even with the
infinitesimals of the human body; and reason, confined to this narrow
range of a subject, perceives herself to be imprisoned, and quenches her
guiding light in despair. Originality has outlived itself; and discovery
is a long-forgotten enterprise, except as pursued in the microcosm on
the field of the microscope, which, it must be confessed, has drawn
forth demonstrations only commensurate in importance with the magnitude
of the littleness there seen.
The subject of our study, whichever it happen to be, may appear
exhausted of all interest, and the promise of valuable novelty, owing to
two reasons:--It may be, like descriptive human anatomy, so cold, poor
and sterile in its own nature, and so barren of product, that it will be
impossible for even the genius of Promethean fire to warm it; or else,
like existing physiology, the very point of view from which the mental
eye surveys the theme, will blight the fair prospect of truth, distort
induction, and clog up the paces of ratiocination. The physiologist of
the present day is too little of a comparative anatomist, and far too
closely enveloped in the absurd jargon of the anthropotomist, ever to
hope to reveal any great truth for science, and dispel the mists which
still hang over the phenomena of the nervous system. He is steeped too
deeply in the base nomenclature of the antique school, and too indolent
to question the import of Pons, Commissure, Island, Taenia, Nates,
Testes, Cornu, Hippocamp, Thalamus, Vermes, Arbor Vitro, Respiratory
Tract, Ganglia of Increase, and all such phrase of unmeaning sound, ever
to be productive of lucid interpretation of the cerebro-spinal ens.
Custom alone sanctions his use of such names; but
"Custom calls him to it!
What custom wills; should custom always do it,
The dust on antique time would lie unswept,
And mountainous error be too highly heaped,
For truth to overpeer."
Of the illustrations of this work I may state, in guarantee of their
anatomical accuracy, that they have been made by myself from my own
dissections, first planned at the London University College, and
afterwards realised at the Ecole Pratique, and School of Anatomy
adjoining the Hospital La Pitie, Paris, a few years since. As far as the
subject of relative anatomy could admit of novel treatment, rigidly
confined to facts unalterable, I have endeavoured to give it.
The unbroken surface of the human figure is as a map to the surgeon,
explanatory of the anatomy arranged beneath; and I have therefore left
appended to the dissected regions as much of the undissected as was
necessary. My object was to indicate the interior through the
superficies, and thereby illustrate the whole living body which concerns
surgery, through its dissected dead counterfeit. We dissect the dead
animal body in order to furnish the memory with as clear an account of
the structure contained in its living representative, which we are not
allowed to analyse, as if this latter were perfectly translucent, and
directly demonstrative of its component parts.
J. M
TABLE OF CONTENTS.
PREFACE
INTRODUCTORY TO THE STUDY OF ANATOMY AS A SCIENCE.
COMMENTARY ON PLATES 1 & 2
THE FORM OF THE THORAX, AND THE RELATIVE POSITION OF ITS
CONTAINED PARTS--THE LUNGS, HEART, AND LARGER BLOOD VESSELS.
The structure, mechanism, and respiratory motions of the thoracic
apparatus. Its varieties in form, according to age and sex. Its
deformities. Applications to the study of physical diagnosis.
COMMENTARY ON PLATES 3 & 4
THE SURGICAL FORM OF THE SUPERFICIAL, CERVICAL, AND FACIAL
REGIONS, AND THE RELATIVE POSITION OF THE PRINCIPAL BLOOD
VESSELS, NERVES, ETC.
The cervical surgical triangles considered in reference to the position
of the subclavian and carotid vessels, &c. Venesection in respect to the
external jugular vein. Anatomical reasons for avoiding transverse
incisions in the neck. The parts endangered in surgical operations on
the parotid and submaxillary glands, &c.
COMMENTARY ON PLATES 5 & 6
THE SURGICAL FORM OF THE DEEP CERVICAL AND FACIAL REGIONS,
AND THE RELATIVE POSITION OF THE PRINCIPAL BLOOD VESSELS,
NERVES, ETC.
The course of the carotid and subclavian vessels in reference to each
other, to the surface, and to their respective surgical triangles.
Differences in the form of the neck in individuals of different age and
sex. Special relations of the vessels. Physiological remarks on the
carotid artery. Peculiarities in the relative position of the subclavian
artery.
COMMENTARY ON PLATES 7 & 8
THE SURGICAL DISSECTION OF THE SUBCLAVIAN AND CAROTID
REGIONS, AND THE RELATIVE ANATOMY OF THEIR CONTENTS.
General observations. Abnormal complications of the carotid and
subclavian arteries. Relative position of the vessels liable to change
by the motions of the head and shoulder. Necessity for a fixed surgical
position in operations affecting these vessels. The operations for tying
the carotid or the subclavian at different situations in cases of
aneurism, &c. The operation for tying the innominate artery. Reasons of
the unfavourable results of this proceeding.
COMMENTARY ON PLATES 9 & 10
THE SURGICAL DISSECTION OF THE EPISTERNAL OR TRACHEAL
REGION, AND THE RELATIVE POSITION OF ITS MAIN BLOOD VESSELS,
NERVES, ETC.
Varieties of the primary aortic branches explained by the law of
metamorphosis. The structures at the median line of the neck. The
operations of tracheotomy and laryngotomy in the child and adult, The
right and left brachio-cephalic arteries and their varieties considered
surgically.
COMMENTARY ON PLATES 11 & 12
THE SURGICAL DISSECTION OF THE AXILLARY AND BRACHIAL
REGIONS, DISPLAYING THE RELATIVE POSITION OF THEIR CONTAINED PARTS.
The operation for tying the axillary artery. Remarks on fractures of the
clavicle and dislocation of the humerus in reference to the axillary
vessels. The operation for tying the brachial artery near the axilla.
Mode of compressing this vessel against the humerus.
COMMENTARY ON PLATES 13 & 14
THE SURGICAL FORMS OF THE MALE AND FEMALE AXILLAE
COMPARED.
The mammary and axillary glands in health and disease. Excision of these
glands. Axillary abscess. General surgical observations on the axilla.
COMMENTARY ON PLATES 15 & 16
THE SURGICAL DISSECTION OF THE BEND OF THE ELBOW AND THE
FOREARM, SHOWING THE RELATIVE POSITION OF THE VESSELS AND NERVES.
General remarks. Operation for tying the brachial artery at its middle
and lower thirds. Varieties of the brachial artery. Venesection at the
bend of the elbow. The radial and ulnar pulse. Operations for tying the
radial and ulnar arteries in several parts.
COMMENTARY ON PLATES 17, 18, & 19
THE SURGICAL DISSECTION OF THE WRIST AND HAND.
General observations. Superficial and deep palmar arches. Wounds of
these vessels requiring a ligature to be applied to both ends. General
surgical remarks on the arteries of the upper limb. Palmar abscess, &c.
COMMENTARY ON PLATES 20 & 21.
THE RELATIVE POSITION OF THE CRANIAL, NASAL,
ORAL, AND PHARYNGEAL CAVITIES, ETC.
Fractures of the cranium, and the operation of trephining anatomically
considered. Instrumental measures in reference to the fauces, tonsils,
oesophagus, and lungs.
COMMENTARY ON PLATE 22
THE RELATIVE POSITION OF THE SUPERFICIAL
ORGANS OF THE THORAX AND ABDOMEN.
Application to correct physical diagnosis. Changes in the relative
position of the organs during the respiratory motions. Changes effected
by disease. Physiological remarks on wounds of the thorax and on
pleuritic effusion. Symmetry of the organs, &c.
COMMENTARY ON PLATE 23
THE RELATIVE POSITION OF THE DEEPER ORGANS
OF THE THORAX AND THOSE OF THE ABDOMEN.
Of the heart in reference to auscultation and percussion. Of the lungs,
ditto. Relative capacity of the thorax and abdomen as influenced by the
motions of the diaphragm. Abdominal respiration. Physical causes of
abdominal herniae. Enlarged liver as affecting the capacity of the
thorax and abdomen. Physiological remarks on wounds of the lungs.
Pneumothorax, emphysema, &c.
COMMENTARY ON PLATE 24
THE RELATIONS OF THE PRINCIPAL BLOODVESSELS TO THE
VISCERA OF THE THORACICO-ABDOMINAL CAVITY.
Symmetrical arrangement of the vessels arising from the median
thoracico-abdominal aorta, &c. Special relations of the aorta. Aortic
sounds. Aortic aneurism and its effects on neighbouring organs.
Paracentesis thoracis. Physical causes of dropsy. Hepatic abscess.
Chronic enlargements of the liver and spleen as affecting the relative
position of other parts. Biliary concretions. Wounds of the intestines.
Artificial anus.
COMMENTARY ON PLATE 25
THE RELATION OF THE PRINCIPAL BLOODVESSELS OF
THE THORAX AND ABDOMEN TO THE OSSEOUS SKELETON.
The vessels conforming to the shape of the skeleton. Analogy between the
branches arising from both ends of the aorta. Their normal and abnormal
conditions. Varieties as to the length of these arteries considered
surgically. Measurements of the abdomen and thorax compared.
Anastomosing branches of the thoracic and abdominal parts of the aorta.
COMMENTARY ON PLATE 26
THE RELATION OF THE INTERNAL PARTS TO THE EXTERNAL SURFACE.
In health and disease. Displacement of the lungs from pleuritic
effusion. Paracentesis thoracis. Hydrops pericardii. Puncturation.
Abdominal and ovarian dropsy as influencing the position of the viscera.
Diagnosis of both dropsies. Paracentesis abdominis. Vascular
obstructions and their effects.
COMMENTARY ON PLATE 27
THE SURGICAL DISSECTION OF THE SUPERFICIAL PARTS AND
BLOODVESSELS OF THE INGUINO-FEMORAL REGION.
Physical causes of the greater frequency of inguinal and femoral
herniae. The surface considered in reference to the subjacent parts.
COMMENTARY ON PLATES 28 & 29
THE SURGICAL DISSECTION OF THE FIRST, SECOND, THIRD, AND
FOURTH LAYERS OF THE INGUINAL REGION, IN CONNEXION WITH THOSE
OF THE THIGH.
The external abdominal ring and spermatic cord. Cremaster muscle--how
formed. The parts considered in reference to inguinal hernia. The
saphenous opening, spermatic cord, and femoral vessels in relation to
femoral hernia.
COMMENTARY ON PLATES 30 & 31
THE SURGICAL DISSECTION OF THE FIFTH, SIXTH, SEVENTH, AND
EIGHTH LAYERS OF THE INGUINAL REGION, AND THEIR CONNEXION WITH
THOSE OF THE THIGH.
The conjoined tendon, internal inguinal ring, and cremaster muscle,
considered in reference to the descent of the testicle and of the
hernia. The structure and direction of the inguinal canal.
COMMENTARY ON PLATES 32, 33, & 34
THE DISSECTION OF THE OBLIQUE OR EXTERNAL,
AND OF THE DIRECT OR INTERNAL INGUINAL HERNIA.
Their points of origin and their relations to the inguinal rings. The
triangle of Hesselbach. Investments and varieties of the external
inguinal hernia, its relations to the epigastric artery, and its
position in the canal. Bubonocele, complete and scrotal varieties in the
male. Internal inguinal hernia considered in reference to the same
points. Corresponding varieties of both herniae in the female.
COMMENTARY ON PLATES 35, 36, 37, & 38
THE DISTINCTIVE DIAGNOSIS BETWEEN EXTERNAL AND INTERNAL
INGUINAL HERNIAE, THE TAXIS, SEAT OF STRICTURE, AND THE OPERATION.
Both herniae compared as to position and structural characters. The
co-existence of both rendering diagnosis difficult. The oblique changing
to the direct hernia as to position, but not in relation to the
epigastric artery. The taxis performed in reference to the position of
both as regards the canal and abdominal rings. The seat of stricture
varying. The sac. The lines of incision required to avoid the epigastric
artery. Necessity for opening the sac.
COMMENTARY ON PLATES 39 & 40
DEMONSTRATIONS OF THE NATURE OF CONGENITAL AND
INFANTILE INGUINAL HERNIAE, AND OF HYDROCELE.
Descent of the testicle. The testicle in the scrotum. Isolation of its
tunica vaginalis. The tunica vaginalis communicating with the abdomen.
Sacculated serous spermatic canal. Hydrocele of the isolated tunica
vaginalis. Congenital hernia and hydrocele. Infantile hernia. Oblique
inguinal hernia. How formed and characterized.
COMMENTARY ON PLATES 41 & 42
DEMONSTRATIONS OF THE ORIGIN AND PROGRESS
OF INGUINAL HERNIAE IN GENERAL.
Formation of the serous sac. Formation of congenital hernia. Hernia in
the canal of Nuck. Formation of infantile hernia. Dilatation of the
serous sac. Funnel-shaped investments of the hernia. Descent of the
hernia like that of the testicle. Varieties of infantile hernia.
Sacculated cord. Oblique internal inguinal hernia--cannot be congenital.
Varieties of internal hernia. Direct external hernia. Varieties of the
inguinal canal.
COMMENTARY ON PLATES 43 & 44
THE DISSECTION OF FEMORAL HERNIA AND THE SEAT OF STRICTURE.
Compared with the inguinal variety. Position and relations. Sheath of
the femoral vessels and of the hernia. Crural ring and canal. Formation
of the sac. Saphenous opening. Relations of the hernia. Varieties of the
obturator and epigastric arteries. Course of the hernia. Investments.
Causes and situations of the stricture.
COMMENTARY ON PLATES 45 & 46
DEMONSTRATIONS OF THE ORIGIN AND PROGRESS OF FEMORAL
HERNIA; ITS DIAGNOSIS, THE TAXIS, AND THE OPERATION.
Its course compared with that of the inguinal hernia. Its investments
and relations. Its diagnosis from inguinal hernia, &c. Its varieties.
Mode of performing the taxis according to the course of the hernia. The
operation for the strangulated condition. Proper lines in which
incisions should be made. Necessity for and mode of opening the sac.
COMMENTARY ON PLATE 47
THE SURGICAL DISSECTION OF THE PRINCIPAL BLOODVESSELS
AND NERVES OF THE ILIAC AND FEMORAL REGIONS.
The femoral triangle. Eligible place for tying the femoral artery. The
operations of Scarpa and Hunter. Remarks on the common femoral artery.
Ligature of the external iliac artery according to the seat of aneurism.
COMMENTARY ON PLATES 48 & 49
THE RELATIVE ANATOMY OF THE MALE PELVIC ORGANS.
Physiological remarks on the functions of the abdominal muscles. Effects
of spinal injuries on the processes of defecation and micturition.
Function of the bladder. Its change of form and position in various
states. Relation to the peritonaeum. Neck of the bladder. The prostate.
Puncturation of the bladder by the rectum. The pudic artery.
COMMENTARY ON PLATES 50 & 51
THE SURGICAL DISSECTION OF THE SUPERFICIAL
STRUCTURES OF THE MALE PERINAEUM.
Remarks on the median line. Congenital malformations. Extravasation of
urine into the sac of the superficial fascia. Symmetry of the parts.
Surgical boundaries of the perinaeum. Median and lateral important parts
to be avoided in lithotomy, and the operation for fistula in ano.
COMMENTARY ON PLATES 52 & 53
THE SURGICAL DISSECTION OF THE DEEP STRUCTURES OF THE MALE
PERINAEUM; THE LATERAL OPERATION OF LITHOTOMY.
Relative position of the parts at the base of the bladder. Puncture of
the bladder through the rectum and of the urethra in the perinaeum.
General rules for lithotomy.
COMMENTARY ON PLATES 54, 55, & 56
THE SURGICAL DISSECTION OF THE MALE BLADDER AND URETHRA;
LATERAL AND BILATERAL LITHOTOMY COMPARED.
Lines of incision in both operations. Urethral muscles--their analogies
and significations. Direction, form, length, structure, &c., of the
urethra at different ages. Third lobe of the prostate. Physiological
remarks. Trigone vesical. Bas fond of the bladder. Natural form of the
prostate at different ages.
COMMENTARY ON PLATES 57 & 58
CONGENITAL AND PATHOLOGICAL DEFORMITIES OF THE PREPUCE AND URETHRA;
STRICTURES AND MECHANICAL OBSTRUCTIONS OF THE URETHRA.
General remarks. Congenital phymosis. Gonorrhoeal paraphymosis and
phymosis. Effect of circumcision. Protrusion of the glans through an
ulcerated opening in the prepuce. Congenital hypospadias. Ulcerated
perforations of the urethra. Congenital epispadias. Urethral fistula,
stricture, and catheterism. Sacculated urethra. Stricture opposite the
bulb and the membranous portion of the urethra. Observations respecting
the frequency of stricture in these parts. Calculus at the bulb. Polypus
of the urethra. Calculus in its membranous portion. Stricture midway
between the meatus and bulb. Old callous stricture, its form, &c.
Spasmodic stricture of the urethra by the urethral muscles. Organic
stricture. Surgical observations.
COMMENTARY ON PLATES 59 & 60.
THE VARIOUS FORMS AND POSITIONS OF STRICTURES AND OTHER
OBSTRUCTIONS OF THE URETHRA; FALSE PASSAGES; ENLARGEMENTS
AND DEFORMITIES OF THE PROSTATE.
General remarks. Different forms of the organic stricture. Coexistence
of several. Prostatic abscess distorting and constricting the urethra.
Perforation of the prostate by catheters. Series of gradual enlargements
of the third lobe of the prostate. Distortion of the canal by the
enlarged third lobe--by the irregular enlargement of the three lobes--by
a nipple-shaped excrescence at the vesical orifice.
COMMENTARY ON PLATES 61 & 62
DEFORMITIES OF THE PROSTATE; DISTORTIONS AND
OBSTRUCTIONS OF THE PROSTATIC URETHRA.
Observations on the nature of the prostate--its signification. Cases of
prostate and bulb pouched by catheters. Obstructions of the vesical
orifice. Sinuous prostatic canal. Distortions of the vesical orifice.
Large prostatic calculus. Sacculated prostate. Triple prostatic urethra.
Encrusted prostate. Fasciculated bladder. Prostatic sac distinct from
the bladder. Practical remarks. Impaction of a large calculus in the
prostate. Practical remarks.
COMMENTARY ON PLATES 63 & 64
DEFORMITIES OF THE URINARY BLADDER; THE OPERATIONS OF SOUNDING FOR STONE;
OF CATHETERISM AND OF PUNCTURING THE BLADDER ABOVE THE PUBES.
General remarks on the causes of the various deformities, and of the
formation of stone. Lithic diathesis--its signification. The sacculated
bladder considered in reference to sounding, to catheterism, to
puncturation, and to lithotomy. Polypi in the bladder. Dilated ureters.
The operation of catheterism. General rules to be followed. Remarks on
the operation of puncturing the bladder above the pubes.
COMMENTARY ON PLATES 65 & 66.
THE SURGICAL DISSECTION OF THE POPLITEAL SPACE,
AND THE POSTERIOR CRURAL REGION.
Varieties of the popliteal and posterior crural vessels. Remarks on
popliteal aneurism, and the operation for tying the popliteal artery, in
wounds of this vessel. Wounds of the posterior crural arteries requiring
double ligatures. The operations necessary for reaching these vessels.
COMMENTARY ON PLATES 67 & 68.
THE SURGICAL DISSECTION OF THE ANTERIOR CRURAL REGION;
THE ANKLES AND THE FOOT.
Varieties of the anterior and posterior tibial and the peronaeal
arteries. The operations for tying these vessels in several situations.
Practical observations on wounds of the arteries of the leg and foot.
CONCLUDING COMMENTARY
ON THE FORM AND DISTRIBUTION OF THE VASCULAR SYSTEM AS A
WHOLE; ANOMALIES; RAMIFICATION; ANASTOMOSIS.
The double heart. Universal systemic capillary anastomosis. Its
division, by the median line, into two great lateral fields--those
subdivided into two systems or provinces--viz., pulmonary and systemic.
Relation of pulmonary and systemic circulating vessels. Motions of the
heart. Circulation of the blood through the lungs and system. Symmetry
of the hearts and their vessels. Development of the heart and primary
vessels. Their stages of metamorphosis simulating the permanent
conditions of the parts in lower animals. The primitive branchial arches
undergoing metamorphosis. Completion of these changes. Interpretation of
the varieties of form in the heart and primary vessels. Signification of
their normal condition. The portal system no exception to the law of
vascular symmetry. Signification of the portal system. The liver and
spleen as homologous organs,--as parts of the same whole quantity.
Cardiac anastomosing vessels. Vasa vasorum. Anastomosing branches of the
systemic aorta considered in reference to the operations of arresting by
ligature the direct circulation through the arteries of the head, neck,
upper limbs, pelvis, and lower limbs. The collateral circulation.
Practical observations on the most eligible situations for tying each of
the principal vessels, as determined by the greatest number of their
anastomosing branches on either side of the ligature, and the largest
amount of the collateral circulation that may be thereby carried on for
the support of distal parts.
[End Table of Contents]
COMMENTARY ON PLATES 1 & 2.
THE FORM OF THE THORACIC CAVITY, AND THE POSITION OF THE LUNGS,
HEART, AND LARGER BLOODVESSELS.
In the human body there does not exist any such space as cavity,
properly so called. Every space is occupied by its contents. The
thoracic space is completely filled by its viscera, which, in mass, take
a perfect cast or model of its interior. The thoracic viscera lie so
closely to one another, that they respectively influence the form and
dimensions of each other. That space which the lungs do not occupy is
filled by the heart, &c., and vice versa. The thoracic apparatus causes
no vacuum by the acts of either contraction or dilatation. Neither do
the lungs or the heart. When any organ, by its process of growth, or by
its own functional act, forces a space for itself, it immediately
inhabits that space entirely at the expense of neighbouring organs. When
the heart dilates, the pulmonary space contracts; and when the thoracic
space increases, general space diminishes in the same ratio.
The mechanism of the functions of respiration and circulation consists,
during the life of the animal, in a constant oscillatory nisus to
produce a vacuum which it never establishes. These vital forces of the
respiratory and circulatory organs, so characteristic of the higher
classes of animals, are opposed to the general forces of surrounding
nature. The former vainly strive to make exception to the irrevocable
law, that "nature abhors a vacuum." This act of opposition between both
forces constitutes the respiratory act, and thus the respiratory
thoracic being (like a vibrating pendulum) manifests respiratory motion,
not as an effort of volition originating solely with itself, but
according to the measure of the force of either law; as entity is
relationary, so is functionality likewise. The being is functional by
relationship; and just as a pendulum is functional, by reason of the
counteraction of two opposing forces,--viz., the force of motion and the
force of gravity,--so is a thoracic cavity (considering it as a
mechanical apparatus) functional by two opposing forces--the vital force
and the surrounding physical force. The inspiration of thoracic space is
the expiration of general space, and reciprocally.
The thoracic space is a symmetrical enclosure originally, which
aftercoming necessities modify and distort in some degree. The spaces
occupied by the opposite lungs in the adult body do not exactly
correspond as to capacity, O O, Plate 1. Neither is the cardiac space, A
E G D, Plate 1, which is traversed by the common median line,
symmetrical. The asymmetry of the lungs is mainly owing to the form and
position of the heart; for this organ inclines towards the left thoracic
side. The left lung is less in capacity than the right, by so much space
as the heart occupies in the left pulmonary side. The general form of
the thorax is that of a cone, I I N N, Plate 1, bicleft through its
perpendicular axis, H M. The line of bicleavage is exactly median, and
passes through the centre of the sternum in front, and the centres of
the dorsal vertebral behind. Between the dorsal vertebral and the
sternum, the line of median cleavage is maintained and sketched out in
membrane. This membranous middle is formed by the adjacent sides of the
opposite pleural or enveloping bags in which the lungs are enclosed. The
heart, A, Plate 1, is developed between these two pleural sacs, F F, and
separates them from each other to a distance corresponding to its own
size. The adjacent sides of the two pleural sacs are central to the
thorax, and form that space which is called mediastinum; the heart is
located in this mediastinum, U E, Plate 1. The extent of the thoracic
region ranges perpendicularly from the root of the neck, Q, Plate 1, to
the roof of the abdomen--viz., the diaphragm, P, transversely from the
ribs of one side, I N, Plate 1, to those of the other, and
antero-posteriorly from the sternum, H M, to the vertebral column. All
this space is pulmonary, except the cardiac or median space, which, in
addition to the heart, A, Plate 1, and great bloodvessels, G C B,
contains the oesophagus, bronchi, &c. The ribs are the true enclosures
of thoracic space, and, generally, in mammalian forms, they fail or
degenerate at that region of the trunk which is not pulmonary or
respiratory. In human anatomy, a teleological reason is given for
this--namely, that of the ribs being mechanically subservient to the
function of respiration alone. But the transcendental anatomists
interpret this fact otherwise, and refer it to the operation of a higher
law of formation.
The capacity of the thorax is influenced by the capacity of the abdomen
and its contents. In order to admit of full inspiration and pulmonary
expansion, the abdominal viscera recede in the same ratio as the lungs
dilate. The diaphragm, P P, Plate 1, or transverse musculo-membranous
partition which divides the pulmonary and alimentary cavities, is, by
virtue of its situation, as mechanically subservient to the abdomen as
to the thorax. And under general notice, it will appear that even the
abdominal muscles are as directly related to the respiratory act as
those of the thorax. The connexion between functions is as intimate and
indissoluble as the connexion between organs in the same body. There can
be no more striking proof of the divinity of design than by such
revelations as anatomical science everywhere manifests in facts such as
this--viz., that each organ serves in most cases a double, and in many a
triple purpose, in the animal economy.
The apex of the lung projects into the root of the neck, even to a
higher level, Q, Plate 1, than that occupied by the sternal end of the
clavicle, K. If the point of a sword were pushed through the neck above
the clavicle, at K, Plate 1, it would penetrate the apex of the right
lung, where the subclavian artery, Q, Plate 1, arches over it. In
connexion with this fact, I may mention it as very probable that the
bruit, or continuous murmur which we hear through the stethoscope, in
chlorotic females, is caused by the pulsation of the subclavian artery
against the top of the lung. The stays or girdle which braces the loins
of most women prevents the expansion of the thoracic apparatus,
naturally attained by the descent of the diaphragm; and hence, no doubt,
the lung will distend inordinately above towards the neck. It is an
interesting fact for those anatomists who study the higher
generalizations of their science, that at those very localities--viz.,
the neck and loins, where the lungs by their own natural effort are
prone to extend themselves in forced inspiration--happen the "anomalous"
creations of cervical and lumbar ribs. The subclavian artery is
occasionally complicated by the presence of these costal appendages.
If the body be transfixed through any one of the intercostal spaces, the
instrument will surely wound some part of the lung. If the thorax be
pierced from any point whatever, provided the instrument be directed
towards a common centre, A, Plate 1, the lung will suffer lesion; for
the heart is, almost completely, in the healthy living body, enveloped
in the lungs. So true is it that all the costal region (the asternal as
well as the sternal) is a pulmonary enclosure, that any instrument which
pierces intercostal space must wound the lung.
As the sternal ribs degenerate into the "false" asternal or incomplete
ribs from before, obliquely backward down to the last dorsal vertebra,
so the thoracic space takes form. The lungs range through a much larger
space, therefore, posteriorly than they do anteriorly.
The form of the thorax, in relation to that of the abdomen, may be
learned from the fact that a gunshot, which shall enter a little below
N, Plate 1, and, after traversing the body transversely, shall pass out
at a corresponding point at the opposite side, would open the thorax and
the abdomen into a common cavity; for it would pierce the thorax at N,
the arching diaphragm at the level of M, and thereat enter the belly;
then it would enter the thorax again at P, and make exit below N,
opposite. If a cutting instrument were passed horizontally from before
backward, a little below M, it would first open the abdomen, then pierce
the arching diaphragm, and pass into the thorax, opposite the ninth or
eighth dorsal vertebra.
The outward form or superficies masks in some degree the form of the
interior. The width of the thorax above does not exceed the diameter
between the points I I, of Plate 1, or the points W W, of Plate 2. If we
make percussion directly from before backwards at any place external to
I, Plate 1, we do not render the lung vibrative. The diameters between I
I and N N, Plate 1, are not equal; and these measures will indicate the
form of the thorax in the living body, between the shoulders above and
the loins below.
The position of the heart in the thorax varies somewhat with several
bodies. The size of the heart, even in a state of perfect health, varies
also in subjects of corresponding ages, a condition which is often
mistaken for pathological. For the most part, its form occupies a space
ranging from two or three lines right of the right side of the sternum
to the middle of the shafts of the fifth and sixth ribs of the left
side. In general, the length of the osseous sternum gives the exact
perpendicular range of the heart, together with its great vessels.
The aorta, C, Plates 1 and 2, is behind the upper half of the sternum,
from which it is separated by the pericardium, D, Plate 1, the thin edge
of the lung, and the mediastinal pleurae, U E, Plate 1, &c. If the heart
be injected from the abdominal aorta, the aortal arch will flatten
against the sternum. Pulmonary space would not be opened by a
penetrating instrument passed into the root of the neck in the median
line above the sternum, at L, Plate 1. But the apices of both lungs
would be wounded if the same instrument entered deeply on either side of
this median line at K K. An instrument which would pierce the sternum
opposite the insertion of the second, third, or fourth costal cartilage,
from H downwards, would transfix some part of the arch of the aorta, C,
Plate 1. The same instrument, if pushed horizontally backward through
the second, third, or fourth interspaces of the costal cartilages close
to the sternum, would wound, on the right of the sternal line, the vena
cava superior, G, Plate 1; on the left, the pulmonary artery, B, and
the descending thoracic aorta. In the healthy living body, the thoracic
sounds heard in percussion, or by means of the stethoscope, will vary
according to the locality operated upon, in consequence of the variable
thickness of those structures (muscular and osseous, &c.,) which invest
the thoracic walls. Uniformity of sound must, owing to these facts, be
as materially interrupted, as it certainly is, in consequence of the
variable contents of the cavity. The variability of the healthy thoracic
sounds will, therefore, be too often likely to be mistaken for that of
disease, if we forget to admit these facts, as instanced in the former
state. Considering the form of the thoracic space in reference to the
general form of the trunk of the living body, I see reason to doubt
whether the practitioner can by any boasted delicacy of manipulation,
detect an abnormal state of the pulmonary organs by percussion, or the
use of the stethoscope, applied at those regions which he terms
coracoid, scapulary, subclavian, &c., if the line of his examination be
directed from before backwards. The scapula, covered by thick carneous
masses, does not lie in the living body directly upon the
osseous-thorax, neither does the clavicle. As all antero-posterior
examination in reference to the lungs external to the points, I I,
between the shoulders cannot, in fact, concern the pulmonary organs, so
it cannot be diagnostic of their state either in health or disease. The
difficulties which oppose the practitioner's examination of the state of
the thoracic contents are already numerous enough, independent of those
which may arise from unanatomical investigation.
DESCRIPTION OF PLATES 1 & 2.
PLATE 1.
A. Right ventricle of the heart.
B. Origin of pulmonary artery.
C. Commencement of the systemic aorta, ascending part of aortic arch.
D. Pericardium investing the heart and the origins of the great
bloodvessels.
E. Mediastinal pleura, forming a second investment for the heart,
bloodvessels, &c.
F. Costal pleura, seen to be continuous above with that which forms
the mediastinum.
G. Vena cava superior, entering pericardium to join V, the right
auricle.
H. Upper third of sternum.
I I. First ribs.
K K. Sternal ends of the clavicles.
L. Upper end of sternum.
M. Lower end of sternum.
N N. Fifth ribs.
O O. Collapsed lungs.
P P. Arching diaphragm.
Q. Subclavian artery.
R. Common carotid artery, at its division into internal and external
carotids.
S S. Great pectoral muscles.
T T. Lesser pectoral muscles.
U. Mediastinal pleura of right side.
V. Right auricle of the heart.
[Illustration: Upper body, showing internal organs of neck and chest.]
Plate 1
PLATE 2.
A. Right ventricle of the heart. A a. Pericardium.
B. Pulmonary artery. B b. Pericardium.
C. Ascending aorta. C c. Transverse aorta.
D. Right auricle.
E. Ductus arteriosus in the loop of left vagus nerve, and close to
phrenic nerve of left side.
F. Superior vena cava.
G. Brachio-cephalic vein of left side.
H. Left common carotid artery.
I. Left subclavian vein.
K. Lower end of left internal jugular vein.
L. Right internal jugular vein.
M. Right subclavian vein.
N. Innominate artery--brachio-cephalic.
O. Left subclavian artery crossed by left vagus nerve.
P. Right subclavian artery crossed by right vagus nerve, whose inferior
laryngeal branch loops under the vessel.
Q. Right common carotid artery
R. Trachea.
S. Thyroid body.
T. Brachial plexus of nerves.
U. Upper end of left internal jugular vein.
V V. Clavicles cut across and displaced downwards.
W W. The first ribs.
X X. Fifth ribs cut across.
Y Y. Right and left mammae.
Z. Lower end of sternum.
[Illustration: Upper body, showing internal organs of neck and chest.]
Plate 2
COMMENTARY ON PLATES 3 & 4.
THE SURGICAL FORM OF THE SUPERFICIAL CERVICAL AND FACIAL
REGIONS, AND THE RELATIVE POSITION OF THE PRINCIPAL
BLOOD-VESSELS, NERVES, &c.
When the neck is extended in surgical position, as seen in Plates 3 and
4, its general outline assumes a quadrilateral shape, approaching to a
square. The sides of this square are formed anteriorly by the line
ranging from the mental symphysis to the top of the sternum, and
posteriorly by a line drawn between the occiput and shoulder. The
superior side of this cervical square is drawn by the horizontal ramus
of the lower maxilla, and the inferior side by the horizontal line of
the clavicle. This square space, R 16, 8, 6, Plate 4, is halved by a
diagonal line, drawn by the sterno-cleido-mastoid muscle B, which cuts
the square into two triangles. In the anterior triangle, F 16, 6, Plate
4, is located the superficial common carotid artery, C, and its
branches, D, with accompanying nerves. In the posterior triangle, 9, 8,
6, Plate 4, is placed the superficial subclavian artery, A, its
branches, L M, and the brachial plexus of nerves, I. Both these
triangles and their contents are completely sheathed by that thin
scarf-like muscle, named platysma myoides, A A, Plate 3, the fibres of
which traverse the neck slantingly in a line, O A, of diagonal direction
opposite to and secant of that of the sterno-mastoid muscle.
When the skin and subcutaneous adipose membrane are removed by careful
dissection from the cervical region, certain structures are exposed,
which, even in the undissected neck, projected on the superficies, and
are the unerring guides to the localities of the blood-vessels and
nerves, &c. In Plate 4, the top of the sternum, 6; the clavicle, 7; the
"Pomum Adami," 1; the lower maxilla at V; the hyoid bone, Z; the
sterno-cleido-mastoid muscle, B; and the clavicular portion of the
trapezius muscle, 8; will readily be felt or otherwise recognised
through the skin, &c. When these several points are well considered in
their relation to one another, they will correctly determine the
relative locality of those structures--the blood-vessels, nerves, &c.,
which mainly concern the surgical operation.
The middle point, between 7, the clavicle, and 6, the sternum, of Plate
4, is marked by a small triangular space occurring between the
clavicular and sternal divisions of the sterno-cleido-mastoid muscle.
This space marks the situation (very generally) of the bifurcation of
the innominate artery into the subclavian and common carotid arteries of
the right side; a penetrating instrument would, if passed into this
space at an inch depth, pierce first the root of the internal jugular
vein, and under it, but somewhat internal, the root of either of these
great arterial vessels, and would wound the right vagus nerve, as it
traverses this region. For some extent after the subclavian and carotid
vessels separate from their main common trunk, they lie concealed
beneath the sterno-mastoid muscle, B, Plate 4, and still deeper beneath
the sternal origins of the sterno-hyoid muscle, 5, and sterno-thyroid
muscle, some of whose fibres are traceable at the intervals. The
omo-hyoid muscle and the deep cervical fascia, as will be presently seen,
conceal these vessels also.
The subclavian artery, A, Plate 4, first appears superficial to the
above-named muscles of the cervical region just at the point where,
passing from behind the scalenus muscle, N, Plate 4, which also conceals
it, it sinks behind the clavicle. The exact locality of the artery in
this part of its course would be indicated by a finger's breadth
external to the clavicular attachment of the sterno-mastoid muscle. The
artery passes beneath the clavicle at the middle of this bone, a point
which is indicated in most subjects by that cellular interval occurring
between the clavicular origins of the deltoid and great pectoral
muscles.
The posterior cervical triangle, 9, 8, 7, Plate 4, in which the
subclavian artery is situated, is again subdivided by the muscle
omo-hyoid into two lesser regions, each of which assumes somewhat of a
triangular shape. The lower one of these embraces the vessel, A, and
those nerves of the brachial plexus, I, which are in contact with it.
The posterior belly of the omo-hyoid muscle, K, and the anterior
scalenus muscle, N, form the sides and apex of this lesser triangular
space, while the horizontal clavicle forms its base. This region of the
subclavian artery is well defined in the necks of most subjects,
especially when the muscles are put in action. In lean but muscular
bodies, it is possible to feel the projection of the anterior scalenus
muscle under the skin, external to the sterno-mastoid. The form of the
omo-hyoid is also to be distinguished in the like bodies. But in all
subjects may be readily recognised that hollow which occurs above the
clavicle, and between the trapezius, 8, and the sterno cleido-mastoid, 7
B, in the centre of which hollow the artery lies.
The contents of the larger posterior cervical triangle, formed by B, the
sterno-mastoid before; 9, the splenius; and 8, the trapezius behind,
and by the clavicle below, are the following mentioned structures--viz.,
A, the subclavian artery, in the third part of its course, as it emerges
from behind N, the scalenus anticus; L, the transversalis colli artery,
a branch of the thyroid axis, which will be found to cross the
subclavian vessel at this region; I, the brachial plexus of nerves,
which lie external to and above the vessel; H, the external jugular
vein, which sometimes, in conjunction with a plexus of veins coming from
behind the trapezius muscle, entirely conceals the artery; M, the
posterior scapular artery, a branch of the subclavian, given off from
the vessel after it has passed from behind the scalenus muscle; O,
numerous lymphatic glands; P, superficial descending branches of the
cervical plexus of nerves; and Q, ascending superficial branches of the
same plexus. All these structures, except some of the lymphatic glands,
are concealed by the platysma myoides A, as seen in Plate 3, and beneath
this by the cervical fascia, which latter shall be hereafter more
clearly represented.
In somewhat the same mode as the posterior half of the omo-hyoid
subdivides the larger posterior triangle into two of lesser dimensions,
the anterior half of the same muscle divides the anterior triangle into
two of smaller capacity.
The great anterior triangle, which is marked as that space inclosed
within the points, 6, the top of the sternum, the mental symphysis and
the angle of the maxilla; and whose sides are marked by the median line
of the neck before, the sterno-mastoid behind, and the ramus of the jaw
above, contains C, the common carotid artery, becoming superficial from
beneath the sterno-mastoid muscle, and dividing into E, the internal
carotid, and D, the external carotid. The anterior jugular vein, 3, also
occupies this region below; while some venous branches, which join the
external and internal jugular veins, traverse it in all directions, and
present obstacles to the operator from their meshy plexiform arrangement
yielding, when divided, a profuse haemorrhage.
The precise locality at which the common carotid appears from under the
sterno-mastoid muscle is, in almost all instances, opposite to the
thyroid cartilage. At this place, if an incision, dividing the skin,
platysma and some superficial branches of nerves, be made along the
anterior border of the sterno-mastoid muscle, and this latter be turned
a little aside, a process of cervical fascia, and beneath it the sheath
of the carotid artery, will successionally disclose themselves. In many
bodies, however, some degree of careful search requires to be made prior
to the full exposure of the vessel in its sheath, in consequence of a
considerable quantity of adipose tissue, some lymphatic glands, and many
small veins lying in the immediate vicinity of the carotid artery and
internal jugular vein. This latter vessel, though usually lying
completely concealed by the sterno-mastoid muscle, is frequently to be
seen projecting from under its fore part. In emaciated bodies, where the
sterno-mastoid presents wasted proportions, it will, in consequence,
leave both the main blood-vessels uncovered at this locality in the
neck.
The common carotid artery ascends the cervical region almost
perpendicularly from opposite the sterno-clavicular articulation to the
greater cornu of the os hyoides. For the greater part of this extent it
is covered by the sterno-mastoid muscle; but as this latter takes an
oblique course backwards to its insertion into the mastoid process,
while the main blood-vessel dividing into branches still ascends in its
original direction, so is it that the artery becomes uncovered by the
muscle. Even the root of the internal carotid, E, may be readily reached
at this place, where it lies on the same plane as the external carotid,
but concealed in great part by the internal jugular vein. It would be
possible, while relaxing the sterno-mastoid muscle, to compress either
the common carotid artery or its main branches against the cervical
vertebral column, if pressure were made in a direction backwards and
inwards. The facial artery V, which springs from the external carotid,
D, may be compressed against the horizontal ramus of the lower jaw-bone
at the anterior border of the masseter muscle. The temporal artery, as
it ascends over the root of the zygoma, may be compressed effectually
against this bony point.
The external jugular vein, H, Plate 4, as it descends the neck from the
angle of the jaw obliquely backwards over the sterno-mastoid muscle, may
be easily compressed and opened in any part of its course. This vein
courses downwards upon the neck in relation to that branch of the
superficial cervical plexus, named auricularis magnus nerve, Q, Plate 4,
G, Plate 3. The nerve is generally situated behind the vein, to which it
lies sometimes in close proximity, and is liable, therefore, to be
accidentally injured in the performance of phlebotomy upon the external
jugular vein. The coats of the external jugular vein, E, Plate 3, are
said to hold connexion with some of the fibres of the platysma-myoides
muscle, A A, Plate 3, and that therefore, if the vessel be divided
transversely, the two orifices will remain patent for a time.
The position of the carotid artery protects the vessel, in some degree,
against the suicidal act, as generally attempted. The depth of the
incision necessary to reach the main blood-vessels from the fore part of
the neck is so considerable that the wound seldom effects more than the
opening of some part of the larynx. The ossified condition of the
thyroid and cricoid parts of the laryngeal apparatus affords a
protection to the vessels. The more oblique the incision happens to be,
the greater probability is there that the wound is comparatively
superficial, owing to the circumstance of the instrument having
encountered one or more parts of the hyo-laryngeal range; but woeful
chance sometimes directs the weapon horizontally through that membranous
interval between the thyroid and hyoid pieces, in which case, as also in
that where the laryngeal pieces persist permanently cartilaginous, the
resistance to the cutting instrument is much less.
The anatomical position of the parotid, H, Plate 3, and submaxillary
glands, W, Plate 4, is so important, that their extirpation, while in a
state of disease, will almost unavoidably concern other principal
structures. Whether the diseased parotid gland itself or a lymphatic
body lying in connexion with it, be the subject of operation, it seldom
happens that the temporo-maxillary branch of the external carotid, F,
escapes the knife. But an accident, much more liable to occur, and one
which produces a great inconvenience afterwards to the subject, is that
of dividing the portio-dura nerve, S, Plate 4, at its exit from the
stylo-mastoid foramen, the consequence being that almost all the muscles
of facial expression become paralyzed. The masseter, L, Plate 3,
pterygoid, buccinator, 15, Plate 4, and the facial fibres of the
platysma muscles, A O, Plate 3, still, however, preserve their power, as
these structures are innervated from a different source. The orbicularis
oculi muscle, which is principally supplied by the portio-dura nerve, is
paralyzed, though it still retains a partial power of contraction, owing
to the anatomical fact that some terminal twigs of the third or motor
pair of nerves of the orbit branch into this muscle.
The facial artery, V, and the facial vein, U, Plate 4, are in close
connexion with the submaxillary gland. Oftentimes they traverse the
substance of it. The lingual nerve and artery lie in some part of their
course immediately beneath the gland. The former two are generally
divided when the gland is excised; the latter two are liable to be
wounded in the same operation.
DESCRIPTION OF PLATES 3 & 4.
PLATE 3.
A A A. Subcutaneous platysma myoides muscle, lying on the face, neck,
and upper part of chest, and covering the structures contained
in the two surgical triangles of the neck.
B. Lip of the thyroid cartilage.
C. Clavicular attachment of the trapezius muscle.
D. Some lymphatic bodies of the post triangle.
E. External jugular vein.
F. Occipital artery, close to which are seen some branches of the
occipitalis minor nerve of the cervical plexus.
G. Auricularis magnus nerve of the superficial cervical plexus.
H. Parotid gland.
I. Temporal artery, with its accompanying vein.
K. Zygoma.
L. Masseter muscle, crossed by the parotid duct, and some fibres of
platysma.
M. Facial vein.
N. Buccinator muscle.
O. Facial artery seen through fibres of platysma.
P. Mastoid half of sterno-mastoid muscle.
Q. Locality beneath which the commencements of the subclavian and
carotid arteries lie.
R. Locality of the subclavian artery in the third part of its course.
S. Locality of the common carotid artery at its division into internal
and external carotids.
[Illustration: Right side of the head, showing blood vessels, muscles
and other internal organs. ]
Plate 3
PLATE 4.
A. Subclavian artery passing beneath the clavicle, where it is crossed
by some blood-vessels and nerves.
B. Sternal attachment of the sterno-mastoid muscle, marking the
situation of the root of common carotid.
C. Common carotid at its point of division, uncovered by sterno-mastoid.
D. External carotid artery branching into lingual, facial, temporal,
and occipital arteries.
E. Internal carotid artery.
F. Temporo-maxillary branch of external carotid artery.
G. Temporal artery and temporal vein, with some ascending temporal
branches of portio-dura nerve.
H. External jugular vein descending from the angle of the jaw, where it
is formed by the union of temporal and maxillary veins.
I. Brachial plexus of nerves in connexion with A, the subclavian
artery.
K. Posterior half of the omo-hyoid muscle.
L. Transversalis colli artery.
M. Posterior scapular artery.
N. Scalenus anticus muscle.
O. Lymphatic bodies of the posterior triangle of neck.
P. Superficial descending branches of the cervical plexus of nerves.
Q. Auricularis magnus nerve ascending to join the portio-dura.
R. Occipital artery, accompanied by its nerve, and also by some
branches of the occipitalis minor nerve, a branch of cervical plexus.
S. Portio-dura, or motor division of seventh pair of cerebral nerves.
T. Parotid duct.
U. Facial vein.
V. Facial artery.
W. Submaxillary gland.
X. Digastric muscle.
Y. Lymphatic body.
Z. Hyoid bone.
1. Thyroid cartilage.
2. Superior thyroid artery.
3. Anterior jugular vein.
4. Hyoid half of omo-hyoid muscle.
5. Sterno-hyoid muscle.
6. Top of the sternum.
7. Clavicle.
8. Trapezius muscle.
9. Splenius capitis and colli muscle.
10. Occipital half of occipito-frontalis muscle.
11. Levator auris muscle.
12. Frontal half of occipito-frontalis muscle.
13. Orbicularis oculi muscle.
14. Zygomaticus major muscle.
15. Buccinator muscle.
16. Depressor anguli oris muscle.
(Page 16)
[Illustration: Right side of the head, showing blood vessels, muscles
and other internal organs. ]
Plate 4
COMMENTARY ON PLATES 5 & 6.
THE SURGICAL FORM OF THE DEEP CERVICAL AND FACIAL REGIONS, AND
THE RELATIVE POSITION OF THE PRINCIPAL BLOODVESSELS AND
NERVES, &c.
While the human cervix is still extended in surgical position, its
deeper anatomical relations, viewed as a whole, preserve the
quadrilateral form. But as it is necessary to remove the
sterno-cleido-mastoid muscle, in order to expose the entire range of the
greater bloodvessels and nerves, so the diagonal which that muscle
forms, as seen in Plates 3 and 4, disappears, and thus both the cervical
triangles are thrown into one common region. Although, however, the
sterno-mastoid muscle be removed, as seen in Plate 5, still the great
bloodvessels and nerves themselves will be observed to divide the
cervical square diagonally, as they ascend the neck from the
sterno-clavicular articulation to the ear.
The diagonal of every square figure is the junction line of the opposite
triangles which form the square. The cervical square being indicated as
that space which lies within the mastoid process and the top of the
sternum--the symphysis of the lower maxilla and the top of the shoulder,
it will be seen, in Plate 5, that the line which the common carotid and
internal jugular vein occupy in the neck, is the diagonal; and hence the
junction line of the two surgical triangles.
The general course of the common carotid artery and internal jugular
vein is, therefore, obliquely backwards and upwards through the diagonal
of the cervical square, and passing, as it were, from the point of one
angle of the square to that of the opposite--viz., from the
sterno-clavicular junction to the masto-maxillary space; and, taking the
anterior triangle of the cervical square to be that space included
within the points marked H 8 A, Plate 5, it will be seen that the common
carotid artery ranges along the posterior side of this anterior
triangle. Again: taking the points 5 Z Y to mark the posterior triangle
of the cervical square, so will it be seen that the internal jugular
vein and the common carotid artery, with the vagus nerve between them,
range the anterior side of this posterior triangle, while the subclavian
artery, Q, passes through the centre of the inferior side of the
posterior triangle, that is, under the middle of the shaft of the
clavicle.
The main blood vessels (apparently according to original design) will be
found always to occupy the centre of the animal fabric, and to seek
deep-seated protection under cover of the osseous skeleton. The
vertebrae of the neck, like those of the back and loins, support the
principal vessels. Even in the limbs the large bloodvessels range
alongside the protective shafts of the bones. The skeletal points are
therefore the safest guides to the precise localities of the
bloodvessels, and such points are always within the easy recognition of
touch and sight.
Close behind the right sterno-clavicular articulation, but separated
from it by the sternal insertions of the thin ribbon-like muscles named
sterno-hyoid and thyroid, together with the cervical fascia, is situated
the brachio-cephalic or innominate artery, A B, Plates 5 and 6, having
at its outer side the internal jugular division of the brachio-cephalic
vein, W K, Plate 5. Between these vessels lies the vagus nerve, E, Plate
6, N, Plate 5. The common carotid artery, internal jugular vein, and
vagus nerve, hold in respect to each other the same relationship in the
neck, as far upwards as the angle of the jaw. While we view the general
lateral outline of the neck, we find that, in the same measure as the
blood vessels ascend from the thorax to the skull, they recede from the
fore-part of the root of the neck to the angle of the jaw, whereby a
much greater interval occurs between them and the mental symphysis, or
the apex of the thyroid cartilage, than happens between them and the top
of the sternum, as they lie at the root of the neck. This variation as
to the width of the interval between the vessels and fore-part of the
neck, in these two situations, is owing to two causes, 1st, the somewhat
oblique course taken by the vessels from below upwards; 2dly, the
projecting development of the adult lower jaw-bone, and also of the
laryngeal apparatus, which latter organ, as it grows to larger
proportions in the male than in the female, will cause the interval at
this place to be much greater in the one than the other. In the infant,
the larynx is of such small size, as scarcely to stand out beyond the
level of the vessels, viewed laterally.
The internal jugular vein is for almost its entire length covered by the
sterno-mastoid muscle, and by that layer of the cervical aponeurosis
which lies between the vessels and the muscle. The two vessels, K C,
Plate 5, with the vagus nerve, are enclosed in a common sheath of
cellular membrane, which sends processes between them so as to isolate
the structures in some degree from one another.
The trunk of the common carotid artery is in close proximity to the
vagus nerve, this latter lying at the vessel's posterior side. The
internal jugular vein, which sometimes lies upon and covering the
carotid, will be found in general separated from it for a little space.
Opposite the os hyoides, the internal jugular vein lies closer to the
common carotid than it does farther down towards the root of the neck.
Opposite to the sterno-clavicular articulation, the internal jugular
vein will be seen separated from the common carotid for an interval of
an inch and more in width, and at this interval appears the root of the
subclavian artery, B, Plates 5 and 6, giving off its primary branches,
viz., the thyroid axis, D, the vertebral and internal mammary arteries,
at the first part of its course.
The length of the common carotid artery varies, of course, according to
the place where the innominate artery below divides, and also according
to that place whereat the common carotid itself divides into internal
and external carotids. In general, the length of the common carotid is
considerable, and ranges between the sterno-clavicular articulation and
the level of the os hyoides; throughout the whole of this length, it
seldom or never happens that a large arterial branch is given off from
the vessel, and the operation of ligaturing the common carotid is
therefore much more likely to answer the results required of that
proceeding than can be expected from the ligature of any part of the
subclavian artery which gives off large arterial branches from every
part of its course.
The sympathetic nerve, R, Plate 6, is as close to the carotid artery
behind, as the vagus nerve, N, Plate 5, and is as much endangered in
ligaturing this vessel. The branch of the ninth nerve, E, Plate 5,
(descendens noni,) lies upon the common carotid, itself or its sheath,
and is likely to be included in the ligature oftener than we are aware
of.
The trunk of the external carotid, D, Plate 5, is in all cases very
short, and in many bodies can scarcely be said to exist, in consequence
of the thyroid, lingual, facial, temporal, and occipital branches,
springing directly from almost the same point at which the common
carotid gives off the internal carotid artery. The internal carotid is
certainly the continuation of the common arterial trunk, while the
vessel named external carotid is only a series of its branches. If the
greater size of the internal carotid artery, compared to that of the
external carotid, be not sufficient to prove that the former is the
proper continuation of the common carotid, a fact may be drawn from
comparative philosophy which will put the question beyond doubt,
namely--that as the common carotid follows the line of the cervical
vertebrae, just as the aorta follows that of the vertebrae of the trunk,
so does the internal carotid follow the line of the cephalic vertebrae.
I liken, therefore, those branches of the so-called external carotid to
be, as it were, the visceral arteries of the face and neck. It would be
quite possible to demonstrate this point of analogy, were this the place
for analogical reasoning.
The common carotid, or the internal, may be compressed against the
rectus capitis anticus major muscle, 13, Plate 6, as it lies on the
fore-part of the vertebral column. The internal maxillary artery, 16,
Plate 6, and the facial artery, G, Plate 5, are those vessels which
bleed when the lower maxilla is amputated. In this operation, the
temporal artery, 15, Plate 6, will hardly escape being divided also, it
lies in such close proximity to the neck and condyle of the jaw-bone.
The subclavian artery, B Q, Plate 5, traverses the root of the neck, in
an arched direction from the sterno-clavicular articulation to the
middle of the shaft of the clavicle, beneath which it passes, being
destined for the arm. In general, this vessel rises to a level
considerably above the clavicle; and all that portion of the arching
course which it makes at this situation over the first rib has become
the subject of operation. The middle of this arching subclavian artery
is (by as much as the thickness of the scalenus muscle, X, Plate 5)
deeper situated than either extremity of the arch of this vessel, and
deeper also than any part of the common carotid, by the same fact. So
many branches spring from all parts of the arch of the subclavian
artery, that the operation of ligaturing this vessel is less successful
than the same operation exercised on others.
The structures which lie in connexion with the arch of the subclavian
also render the operation of tying the vessel an anxious task. It is
crossed and recrossed at all points by large veins, important nerves,
and by its own principal branches. The vagus nerve, S E, Plate 6,
crosses it at B, its root; external to which place the large internal
jugular vein, K, Plate 5, lies upon it; external to this latter, the
scalenus muscle, X, Plate 5, with the phrenic nerve lying upon the
muscle, binds it fixedly to the first rib; more external still, the
common trunk of the external jugular and shoulder veins, U, Plate 5, lie
upon the vessel, and it is in the immediate vicinity of the great
brachial plexus of nerves, P P, which pass down along its humeral
border, many branches of the same plexus sometimes crossing it
anteriorly.
The depth at which the middle of the subclavian artery lies may be
learned by the space which those structures, beneath which it passes,
necessarily occupy. The clavicle at its sternal end is round and thick,
where it gives attachment to the sterno-cleido-mastoid muscle. The root
of the internal jugular vein, when injected, will be seen to occupy
considerable space behind the clavicle; and the anterior scalenus muscle
is substantial and fleshy. The united spaces occupied by these
structures give the depth of the subclavian artery in the middle part of
its course.
The length of the subclavian artery between its point of branching from
the innominate and that where it gives off its first branches varies in
different bodies, but is seldom so extensive as to assure the operator
of the ultimate success of the process of ligaturing the vessel. Above
and below D, Plate 6, the thyroid axis, come off the vertebral and
internal mammary arteries internal and anterior to the scalenus muscle.
External and posterior to the scalenus, a large vessel, the post
scapular, G, Plate 6, R, Plate 5, arises. If an aneurism attack any part
of this subclavian arch, it must be in close connexion with some one of
these branches. If a ligature is to be applied to any part of the arch,
it will seldom happen that it can be placed farther than half an inch
from some of these principal collateral branches.
When the shoulder is depressed, the clavicle follows it, and the
subclavian artery will be more exposed and more easily reached than if
the shoulder be elevated, as this latter movement raises the clavicle
over the locality of the vessel. Dupuytren alludes practically to the
different depths of the subclavian artery in subjects with short necks
and high shoulders, and those with long necks and pendent shoulders.
When the clavicle is depressed to the fullest extent, if then the
sterno-cleido-mastoid and scalenus muscles be relaxed by inclining the
head and neck towards the artery, I believe it may be possible to arrest
the flow of blood through the artery by compressing it against the first
rib, and this position will also facilitate the operation of ligaturing
the vessel.
The subclavian vein, W, Plate 5, is removed to some distance from the
artery, Q, Plate 5. The width of the scalenus muscle, X, separates the
vein from the artery. An instance is recorded by Blandin in which the
vein passed in company with the artery under the scalenus muscle.
DESCRIPTION OF PLATES 5 & 6.
PLATE 5.
A. Innominate artery at its point of bifurcation.
B. Subclavian artery crossed by the vagus nerve.
C. Common carotid artery with the vagus nerve at its outer side, and
the descendens noni nerve lying on it.
D. External carotid artery.
E. Internal carotid artery with the descendens noni nerve lying on it.
F. Lingual artery passing under the fibres of the hyo-glossus muscle.
G. Tortuous facial artery.
H. Temporo-maxillary artery.
I. Occipital artery crossing the internal carotid artery and jugular
vein.
K. Internal jugular vein crossed by some branches of the cervical
plexus, which join the descendens noni nerve.
L. Spinal accessory nerve, which pierces the sterno-mastoid muscle, to
be distributed to it and the trapezius.
M. Cervical plexus of nerves giving off the phrenic nerve to descend
the neck on the outer side of the internal jugular vein and over the
scalenus muscle.
N. Vagus nerve between the carotid artery and internal jugular vein.
O. Ninth or hypoglossal nerve distributed to the muscles of the tongue.
P P. Branches of the brachial plexus of nerves.
Q. Subclavian artery in connexion with the brachial plexus of nerves.
R R. Post scapular artery passing through the brachial plexus.
S. Transversalis humeri artery.
T. Transversalis colli artery.
U. Union of the post scapular and external jugular veins, which enter
the subclavian vein by a common trunk.
V. Post-half of the omo-hyoid muscle.
W. Part of the subclavian vein seen above the clavicle.
X. Scalenus muscle separating the subclavian artery from vein.
Y. Clavicle.
Z. Trapezius muscle.
1. Sternal origin of sterno-mastoid muscle of left side.
2. Clavicular origin of sterno-mastoid muscle of right side turned
down.
3. Scalenus posticus muscle.
4. Splenius muscle.
5. Mastoid insertion of sterno-mastoid muscle.
6. Internal maxillary artery passing behind the neck of lower jaw-bone.
7. Parotid duct.
8. Genio-hyoid muscle.
9. Mylo-hyoid muscle, cut and turned aside.
10. Superior thyroid artery.
11. Anterior half of omo-hyoid muscle.
12. Sterno-hyoid muscle, cut.
13. Sterno-thyroid muscle, cut.
[Illustration: Right side of the head and neck, showing blood vessels,
muscles and other internal organs.]
Plate 5
PLATE 6.
A. Root of the common carotid artery.
B. Subclavian artery at its origin.
C. Trachea.
D. Thyroid axis of the subclavian artery.
E. Vagus nerve crossing the origin of subclavian artery.
F. Subclavian artery at the third division of its arch.
G. Post scapular branch of the subclavian artery.
H. Transversalis humeri branch of subclavian artery.
I. Transversalis colli branch of subclavian artery.
K. Posterior belly of omo-hyoid muscle, cut.
L. Median nerve branch of brachial plexus.
M. Musculo-spiral branch of same plexus.
N. Anterior scalenus muscle.
O. Cervical plexus giving off the phrenic nerve, which takes tributary
branches from brachial plexus of nerves.
P. Upper part of internal jugular vein.
Q. Upper part of internal carotid artery.
R. Superior cervical ganglion of sympathetic nerve.
S. Vagus nerve lying external to sympathetic nerve, and giving off t
its laryngeal branch.
T. Superior thyroid artery.
U. Lingual artery separated by hyo-glossus muscle from
V. Lingual or ninth cerebral nerve.
W. Sublingual salivary gland.
X. Genio-hyoid muscle.
Y. Mylo-hyoid muscle, cut and turned aside.
Z. Thyroid cartilage.
1. Upper part of sterno-hyoid muscle.
2. Upper part of omo-hyoid muscle.
3. Inferior constrictor of pharynx.
4. Cricoid cartilage.
5. Crico-thyroid muscle.
6. Thyroid body.
7. Inferior thyroid artery of thyroid axis.
8. Sternal tendon of sterno-mastoid muscle, turned down.
9. Clavicular portion of sterno-mastoid muscle, turned down.
10. Clavicle.
11. Trapezius muscle.
12. Scalenus posticus muscle.
13. Rectus capitis anticus major muscle.
14. Stylo-hyoid muscle, turned aside.
15. Temporal artery.
16. Internal maxillary artery.
17. Inferior dental branch of fifth pair of cerebral nerves.
18. Gustatory branch of fifth pair of nerves.
19. External pterygoid muscle.
20. Internal pterygoid muscle.
21. Temporal muscle cut to show the deep temporal branches of fifth pair
of nerves.
22. Zygomatic arch.
23. Buccinator muscle, with buccal nerve and parotid duct.
24. Masseter muscle cut on the lower maxilla.
25. Middle constrictor of pharynx.
[Illustration: Right side of the head and neck, showing blood vessels,
muscles and other internal organs.]
Plate 6
COMMENTARY ON PLATES 7 & 8.
THE SURGICAL DISSECTION OF THE SUBCLAVIAN AND CAROTID REGIONS,
THE RELATIVE ANATOMY OF THEIR CONTENTS.
A perfect knowledge of the relative anatomy of any of the surgical
regions of the body must include an acquaintance with the superposition
of parts contained in each region, as well as the plane relationship of
organs which hold the same level in each layer or anatomical stratum.
The dissections in Plates 7 and 8 exhibit both these modes of relation.
A portion of each of those superficial layers, which it was necessary to
divide, in order to expose a deeper organ, has been left holding its
natural level. Thus the order of superposition taken by the integument,
the fasciae, the muscles, bones, veins, nerves, and arteries, which
occupy both the surgical triangles of the neck, will be readily
recognised in the opposite Plates.
The depth of a bloodvessel or other organ from surface will vary for
many reasons, even though the same parts in the natural order of
superposition shall overlie the whole length of the vessel or organ
which we make search for. The principal of those reasons are:--1st, that
the stratified organs themselves vary in thickness at several places;
2d, that the organ or vessel which we seek will itself incline to
surface from deeper levels occupied elsewhere; 3d, that the normal
undulations of surface will vary the depth of the particular vessels,
&c.; and 4th, that the natural mobility of the superimposed parts will
allow them to change place in some measure, and consequently influence
the relative position of the object of search. On this account it is
that the surgical anatomist chooses to give a fixed position to the
subject about to be operated on, in order to reduce the number of these
difficulties as much as possible.
In Plate 7 will be seen the surgical relationship of parts lying in the
vicinity of the common carotid artery, at the point of its bifurcation
into external and internal carotids. At this locality, the vessel will
be found, in general, subjacent to the following mentioned structures,
numbered from the superficies to its own level--viz., the common
integument and subcutaneous adipose membrane, which will vary in
thickness in several individuals; next, the platysma myoides muscle, F
L, which is identified with the superficial fascia, investing the outer
surface of the sterno-mastoid muscle; next, the deeper layer of the same
fascia, R S., which passes beneath the sterno-mastoid muscle, but over
the sheath of the vessels; and next, the sheath of the vessels, Q, which
invests them and isolates them from adjacent structures. Though the
vessel lies deeper than the level of the sterno-mastoid muscle at this
locality, yet it is not covered by the muscle in the same manner, as it
is lower down in the neck. At this place, therefore, though the actual
depth of the artery from surface will be the same, whether it be covered
or uncovered by the sterno-mastoid muscle, still we know that the
locality of the vessel relative to the parts actually superimposed will
vary accordingly. This observation will apply to the situation and
relative position of all the other vessels as well. Other occurrences
will vary the relations of the artery in regard to superjacent
structures, though the actual depth of the vessel from surface may be
the same. If the internal jugular vein covers the carotid artery, as it
sometimes does, or if a plexus of veins, gathering from the fore-part of
the neck or face, overlie the vessel, or if a chain of lymphatic bodies
be arranged upon it, as is frequently the case, the knowledge of such
occurrences will guard the judgment against being led into error by the
conventionalities of the descriptive method of anatomists. The normal
relative anatomy of the bloodvessels is taken by anatomists to be the
more frequent disposition of their main trunks and branches, considered
per se, and in connexion with neighbouring parts. But it will be seen by
this avowal that those vessels are liable to many various conditions;
and such is the case, in fact. No anatomist can pronounce with exactness
the precise figure of vessels or other organs while they lie concealed
beneath the surface. An approach to truth is all that the best
experience can boast of. The form and relations of the carotid vessels
of Plate 7 may or may not be the same as those concealed beneath the
same region of Plate 8, at the point R.
The motions of the head upon the neck, or of the neck upon the trunk,
will influence the relative position of the vessels A C B, of Plate 7,
and therefore we take a fixed surgical position, in the expectation of
finding that the carotid artery projects from under the anterior border
of the upper third of the sterno-mastoid muscle, opposite the upper
border of the thyroid cartilage; at this situation of the vessels, viz.,
R, Plate 8, opposite O, the thyroid projection, is in general to be
found the anatomical relation of the vessels as they appear dissected in
Plate 7. Of these vessels, the main trunks are less liable to anomalous
character than the minor branches.
The relative position of the subclavian artery is as liable to be
influenced by the motions of the clavicle on the sternum, as that of the
carotid is by the motions of the lower jaw-bone on the skull, or by the
larynx, in its own motions at the fore-part of the neck. It becomes as
necessary, therefore, in the performance of surgical operations upon the
subclavian artery, to fix the clavicle by depressing it, as in Plate 8,
as it is to give fixity to the lower maxilla and larynx, in the position
of Plate 7, when the carotid is the subject of operation.
The same named structures, but different as to their parts, will be
found to overlie the subclavian artery as are found to conceal the
carotid artery. The skin, the fascia, and platysma muscle, the
sterno-cleido-mastoid muscle, the deep layer of the cervical fascia,
&c., cover both vessels. One additional muscle binds down the subclavian
artery, viz., the scalenus anticus. The omo-hyoid relates to both
vessels, the anterior division to the carotid, the posterior to the
subclavian.
The carotid artery lies uncovered by the sterno-mastoid muscle, opposite
to the upper border of the thyroid cartilage, or the hyoid bone; and the
subclavian artery emerges from under cover of a different part of the
same muscle, opposite the middle of the clavicle. These points of
relationship to the skeletal parts can be ascertained by the touch, in
both instances, even in the undissected body. The thyroid point, O, of
Plate 8, indicates the line, R N, which the carotid artery traverses in
the same figure, along the anterior border of the sterno-mastoid muscle,
as seen in the dissected region of Plate 7. The mid-point of the
clavicle, U, Plate 7, and the top of the sternum in the same figure,
will, while the eye follows the arching line, Z X T V, indicate with
correctness the arching course of the subclavian, such as is represented
in the dissection of that vessel, B, Plate 8.
The subclavian artery has no special sheath, properly so called; but the
deep layer of the cervical fascia, P, Plate 8, which passes under A, the
clavicular portion of the sterno-mastoid muscle, and becomes of
considerable thickness and density, sheaths over the vessel in this
region of its course.
A very complex condition of the veins which join the external jugular at
this part of the course of the subclavian artery is now and then to be
found overlying that vessel. If the hemorrhage consequent upon the
opening of these veins, or that of the external jugular, be so profuse
as to impede the operation of ligaturing the subclavian artery, it may
in some measure be arrested by compressing them against the resisting
parts adjacent, when the operator, feeling for D, the scalenus muscle,
and the first rib to which it is attached, cannot fail to alight upon
the main artery itself, B, Plate 8.
The middle of the shaft of the clavicle is a much safer guide to the
vessel than are the muscles which contribute to form this posterior
triangle of the neck, in which the subclavian vessel is located. The
form or position of the clavicle in the depressed condition of the
shoulder, as seen in Plate 8, is invariable; whereas that of the
trapezius and sterno-mastoid muscles is inconstant, these muscles being
found to stand at unequal intervals from each other in several bodies.
The space between the insertions of both these muscles is indefinite,
and may vary in degrees of width from the whole length of the clavicle
to half an inch; or, as in some instances, leaving no interval whatever.
The position of the omo-hyoid muscle will not be accounted a sure guide
to the locality of the subclavian artery, since, in fact, it varies
considerably as to its relationship with that vessel. The tense cords of
the brachial plexus of nerves, F, Plate 8, which will be found, for the
most part, ranging along the acromial border of the artery, are a much
surer guide to the vessel.
On comparing the subclavian artery, at B, Plate 8, with the common
carotid artery, at A, Plate 7, I believe that the former will be found
to exhibit, on the whole a greater constancy in respect to the
following-mentioned condition--viz., a single main arterial trunk arches
over the first rib to pass beneath the middle of the clavicle, while the
carotid artery opposite the thyroid piece of the larynx is by no means
constantly single as a common carotid trunk. The place of division of
the common carotid is not definite, and, therefore, the precise
situation in the upper two-thirds of the neck, where it may present as a
single main vessel, cannot be predicted with certainty in the
undissected body. There is no other main artery of the body more liable
to variation than that known as external carotid. It is subject to as
many changes of character in respect to the place of its branching from
the common carotid, and also in regard to the number of its own
branches, as any of the lesser arteries of the system. It is but as an
aggregate of the branches of that main arterial trunk which ranges from
the carotid foramen of the temporal bone to the aorta; and, as a branch
of a larger vessel, it is, therefore, liable to spring from various
places of the principal trunk, just as we find to be the case with all
the other minor branches of the larger arteries. Its name, external
carotid, is as unfittingly applied to it, in comparison with the vessel
from which it springs, as the name external subclavian would be if
applied to the thyroid axis of the larger subclavian vessel. The
nomenclature of surgical anatomy does not, however, court a
philosophical inquiry into that propriety of speech which comparative
science demands, nor is it supposed to be necessary in a practical point
of view.
It will, however, sound more euphoneously with reason, and at the same
time, I believe, be found not altogether unrelated to the useful, if,
when such conditions as the "anomalies of form" present themselves, we
can advance an interpretation of the same, in addition to the dry record
of them as isolated facts. Comparative anatomy, which alone can furnish
these interpretations, will therefore prove to be no alien to the
practical, while it may lend explanation to those bizarreries which
impede the way of the anthropotomist. All the anomalies of form, both as
regards the vascular, the muscular, and the osseous systems of the human
body, are analyzed by comparison through the animal series. Numerous
cases are on record of the subclavian artery being found complicated
with supernumerary ribs jutting from the 5th, 6th, or 7th cervical
vertebrae. [Footnote] To these I shall add another, in respect of the
carotid arteries--viz., that I have found them complicated with an
osseous shaft of bone, taking place of the stylo-hyoid ligament, a
condition which obtains permanently in the ruminant and other classes of
mammals.
[Footnote: I have given an explanation of these facts in my work on
Comparative Osteology and the Archetype Skeleton, to which, and also to
Professor Owen's work, entitled Homologies of the Vertebrate Skeleton, I
refer the reader.]
DESCRIPTION OF PLATES 7 & 8.
PLATE 7.
A. Common carotid at its place of division.
B. External carotid.
C. Internal carotid, with the descending branch of the ninth nerve lying
on it.
D. Facial vein entering the internal jugular vein.
E. Sterno-mastoid muscle, covered by
F. Part of the platysma muscle.
G. External jugular vein.
H. Parotid gland, sheathed over by the cervical fascia.
I. Facial vein and artery seen beneath the facial fibres of the platysma.
K. Submaxillary salivary gland.
L. Upper part of the platysma muscle cut.
M. Cervical fascia cut.
N. Sterno-hyoid muscle.
O. Omo-hyoid muscle.
P. Sterno-thyroid muscle.
Q. Fascia proper of the vessels.
R. Layer of the cervical fascia beneath the sterno-mastoid muscle.
S. Portion of the same fascia.
T. External jugular vein injected beneath the skin.
U. Clavicle at the mid-point, where the subclavian artery passes
beneath it.
V. Locality of the subclavian artery in the third part of its course.
W. Prominence of the trapezius muscle.
X. Prominence of the clavicular portion of the sterno-cleido-mastoid
muscle.
Y. Place indicating the interval between the clavicular and sternal
insertions of sterno-cleido-mastoid muscle.
Z. Projection of the sternal portion of the sterno-cleido-mastoid
muscle.
[Illustration: Right side of the head and neck, showing blood vessels,
muscles and other internal organs.]
Plate 7
PLATE 8.
A. Clavicular attachment of the sterno-mastoid muscle lying over the
internal jugular vein, &c.
B. Subclavian artery in the third part of its course.
C. Vein formed by the union of external jugular, scapular, and other
veins.
D. Scalenus anticus muscle stretching over the artery, and separating it
from the internal jugular vein.
E. Post-half of omo-hyoid muscle.
F. Inner branches of the brachial plexus of nerves.
G. Clavicular portion of trapezius muscle.
H. Transversalis colli artery.
I. Layer of the cervical fascia, which invests the sterno-mastoid and
trapezius muscles.
K. Lymphatic bodies lying between two layers of the cervical fascia.
L. Descending superficial branches of the cervical plexus of nerves.
M. External jugular vein seen under the fascia which invests the
sterno-mastoid muscle.
N. Platysma muscle cut on the body of sterno-mastoid muscle.
O. Projection of the thyroid cartilage.
P. Layer of the cervical fascia lying beneath the clavicular portion of
the sterno-mastoid muscle.
Q. Layer of the cervical fascia continued from the last over the
subclavian artery and brachial plexus of nerves.
[Illustration: Right side of the head and neck, showing blood vessels,
muscles and other internal organs.]
Plate 8
COMMENTARY ON PLATES 9 & 10.
THE SURGICAL DISSECTION OF THE STERNO-CLAVICULAR OR TRACHEAL
REGION, AND THE RELATIVE POSITION OF ITS MAIN BLOODVESSELS,
NERVES, &c.
The law of symmetry governs the development of all structures which
compose the human body; and all organized beings throughout the animal
kingdom are produced in obedience to this law. The general median line
of the human body is characterized as the point of fusion of the two
sides; and all structures or organs which range this common centre are
either symmetrically azygos, or symmetrically duplex. The azygos organ
presents as a symmetrical unity, and the duplex organ as a symmetrical
duality. The surgical anatomist takes a studious observation of this law
of symmetry; and knowing it to be one of general and almost
unexceptional occurrence, he practises according to its manifestation.
The vascular as well as the osseous skeleton displays the law of
symmetry; but while the osseous system offers no exception to this law,
the vascular system offers one which, in a surgical point of view, is of
considerable importance--namely, that behind the right sterno-clavicular
articulation, C, Plate 9, is found the artery, A, named innominate, this
being the common trunk of the right common carotid and subclavian
vessels; while on the left side, behind the left sterno-clavicular
junction, Q, Plate 10, the two vessels (subclavian, B, and carotid, A,)
spring separately from the aortic arch. This fact of asymmetrical
arrangement in the arterial trunks at the fore part of the root of the
neck is not, however, of invariable occurrence; on the contrary,
numerous instances are observed where the arteries in question, on the
right side as well as the left, arise separately from the aorta; and
thus Nature reverts to the original condition of perfect symmetry as
governing the development of even the vascular skeleton. And not
unfrequently, as if to invite us to the inquiry whether a separate
origin of the four vessels (subclavian and carotid) from the aorta, or a
double innominate condition of the vessels, were the original form with
Nature, we find her also presenting this latter arrangement of them. An
innominate or common aortic origin may happen for the carotid and
subclavian arteries of the left side, as well as the right. Hence,
therefore, while experience may arm the judgment with a general rule,
such generality should not render us unmindful of the possible
exception.
When, as in Plate 9, A, the innominate artery rises to a level with C,
the right sterno-clavicular junction, and when at this place it
bifurcates, having on its left side, D, the trachea, and on its right
side, B, the root of the internal jugular vein, together with a, the
vagus nerve, the arterial vessel is said to be of normal character, and
holding a normal position relative to adjacent organs. When, as in Plate
10, A, the common carotid, and B, the subclavian artery, rise separately
from the aortic arch to a level with Q, the left sterno-clavicular
articulation, the vessels having M, the trachea, to their inner side,
and C D, the junction of the internal jugular and subclavian veins, to
their outer side, with b, the left vagus nerve, between them, then the
arterial vessels are accounted as being of normal character, and as
holding a normal relative position. Every exception to this condition of
A, Plate 9, or to that of A B, Plate 10, is said to be abnormal or
peculiar, and merely because the disposition of the vessels, as seen in
Plates 9 and 10, is taken to be general or of more frequent occurrence.
Now, though it is not my present purpose to burden this subject of
regional anatomy with any lengthy inquiry into the comparative meaning
of the facts, why a common innominate trunk should occur on the right of
the median line, while separate arterial trunks for the carotid and
subclavian arteries should spring from the aorta on the left of this
mid-line, thus making a remarkable exception to the rule of symmetry
which characterizes all the arterial vessels elsewhere, still I cannot
but regard this exceptional fact of asymmetry as in itself expressing a
question by no means foreign to the interests of the practical.
In the abstract or general survey of all those peculiarities of length
to which the innominate artery, A, Plate 9, is subject, I here lay it
down as a proposition, that they occur as graduated phases of the
bicleavage of this innominate trunk from the level of A, to the aortic
arch, in which latter phasis the aorta gives a separate origin to the
carotid and subclavian vessels of the right side as well as the left. On
the other hand, I observe that the peculiarities to the normal separate
condition of A and B, the carotid and subclavian arteries of Plate 10,
display, in the relationary aggregate, a phasial gradation of A and B
joining into a common trunk union, in which state we then find the aorta
giving origin to a right and left innominate artery. Between these two
forms of development--viz., that where the four vessels spring
separately from the aortic arch, and that where two innominate or
brachio-cephalic arteries arise from the same--may be read all the sum
of variation to which these vessels are liable. It is true that there
are some states of these vessels which cannot be said to be naturally
embraced in the above generalization; but though I doubt not that these
might be encompassed in a higher generalization; still, for all
practical ends, the lesser general rule is all-sufficient.
In many instances, the innominate artery, A, Plate 9, is of such
extraordinary length, that it rises considerably (for an inch, or even
more) above the level of C, the sternal end of the clavicle. In other
cases, the innominate artery bifurcates soon after it leaves the first
part of the aortic arch; and between these extremes as to length, the
vessel varies infinitesimally.
The innominate artery lies closer behind the right sterno-clavicular
junction than the left carotid or subclavian arteries lie in relation to
the left sterno-clavicular articulation; and this difference of depth
between the vessel of the right side and those of the left is mainly
owing to the form and direction of the aortic arch from which they take
origin. The aortic arch ranges, not alone transversely, but also from
before backward, and to the left side of the dorsal spine; and
consequently, as the innominate artery, A, Plate 9, springs from the
first or fore part of the aorta, while the left carotid and subclavian
arteries arise from the second and deeper part of its arch, the vessels
of both sides rising into the neck perpendicularly from the root in the
thorax, will still, in the cervical region, manifest a considerable
difference as to antero-posterior depth. The depth of the left
subclavian artery, B, Plate 10, from cervical surface, is even greater
than that of the left common carotid, A, Plate 10, and this latter, at
its root in the aortic arch, is deeper than the innominate artery. Both
common carotids, A A, Plates 9 and 10, hold nearly the same
antero-posterior depth on either side of the trachea, M, Plate 10, and
D, Plate 9. Although the relative depth of the arterial vessels on both
sides of the trachea is different, still they are covered by an equal
number of identical structures, taking the same order of superposition.
On either side of the episternal cervical pit, which, even in the
undissected body of male or female, infant or adult, is always a
well-marked surgical feature, may be readily recognised the converging
sternal attachments of the sterno-mastoid muscles, L G, Plate 10; and
midway between these symmetrical muscular prominences in the neck, but
holding a deeper level than them, is situated that part of the trachea
which is generally the subject of the operation of tracheotomy. The
relative anatomy of the trachea, M, Plate 10, D, Plate 9, at this
situation requires therefore to be carefully considered. The trachea is
said to incline rather to the right side of the median line; but perhaps
this observation would be more true to nature if it were accompanied by
the remark, that this seeming inclination to the right side is owing to
the fact, that the innominate artery, A, Plate 9, lies obliquely over
its fore part, near the sternum. However this may be, it certainly will
be the safer step in the operation to regard the median position of the
trachea as fixed, than to encroach upon the locality of the carotid
vessels; and to make the incision longitudinally and exactly through the
median line, while the neck is extended backwards, and the chin made to
correspond with the line of incision. And when the operator takes into
consideration the situation of the vessel A, Plate 9, and A, Plate 10,
at this region of the neck, he will at once own to the necessity of
opening the trachea, D, Plate 9, M, Plate 10, at a situation nearer the
larynx than the point marked in the figures. The course taken by the
common carotid arteries is, in respect to the trachea, divergent from
below upwards; and as these vessels will consequently be found to stand
wider apart at the level of K, I, Plate 10, than they do at the level of
M, Plate 10, so the farther upwards from the sternum we choose the point
at which to open the trachea, the less likely are we to endanger the
great arterial vessels.
In addition to the fact, that the carotid arteries at an inch above the
sternum lie nearer the median line than they do higher up in the neck,
it should always be remembered, that the trachea itself is situated much
deeper at the point M, Plate 10, D, Plate 9, than it is opposite the
points F and K of the same figures. The laryngo-tracheal line is, in the
lateral view of the neck, downwards and backwards, and therefore it will
be found always at a considerable depth from cervical surface, as it
passes behind the first bone of the sternum, midway between both
sterno-mastoid muscles.
In the operation of tracheotomy, the cutting instrument divides the
following named structures as they lie beneath the common integument: If
the incision be made directly upon the median line, the muscles F,
sterno-hyoid, and E, sterno-thyroid, Plate 9, are not necessarily
divided, as these structures and their fellows hold a somewhat lateral
position opposite to each other. Beneath these muscles and above them,
thus encasing them, the cervical fascia, f f, Plate 10, is required to
be divided, in order to expose the trachea. Beneath f f the cervical
fascia, will next be felt the rounded bilobed mass of the thyroid body,
lying on the forepart of the trachea; above the thyroid body, the
cricoid and some tracheal cartilaginous rings will be felt; and since
the thyroid body varies much as to bulk in several individuals of the
same and different sexes, as also from a consideration that its
substance is traversed by large arterial and venous vessels, it will be
therefore preferable to open the trachea above it, than through it or
below it.
On the forepart of the tracheal median line, either superficial to, or
deeper than, the cervical fascia, the tracheotomist occasionally meets
with a chain of lymphatic glands or a plexus of veins, which latter,
when divided, will trammel the operation by the copious haemorrhage
which all veins at this region of the neck are prone to supply, owing to
their direct communication with the main venous trunks of the heart; and
not unfrequently the inferior thyroid artery overlies the trachea at the
point D, Plate 9, when this thyroid vessel arises directly from the arch
of the aorta, between the roots of the innominate and left common
carotid, or when it springs from the innominate itself. The inferior
thyroid vein, sometimes single and sometimes double, overlies the
trachea at the point D, Plate 9, when this vein opens into the left
innominate venous trunk, as this latter crosses over the root of the
main arteries springing from the aorta.
Laryngotomy is, anatomically considered, a far less dangerous operation
than tracheotomy, for the above-named reasons; and the former should
always be preferred when particular circumstances do not render the
latter operation absolutely necessary. In addition to the fact, that the
carotid arteries lie farther apart from each other and from the median
place--viz., the crico-thyroid interval, which is the seat of
laryngotomy--than they do lower down on either side of the trachea, it
should also be noticed that the tracheal tube being more moveable than
the larynx, is hence more liable to swerve from the cutting instrument,
and implicate the vessels. Tracheotomy on the infant is a far more
anxious proceeding than the same operation performed on the adult;
because the trachea in the infant's body lies more closely within the
embrace of the carotid arteries, is less in diameter, shorter, and more
mobile than in the adult body.
The episternal or interclavicular region is a locality traversed by so
many vitally important structures gathered together in a very limited
space, that all operations which concern this region require more steady
caution and anatomical knowledge than most surgeons are bold enough to
test their possession of. The reader will (on comparing Plates 9 and 10)
be enabled to take account of those structures which it is necessary to
divide in the operation required for ligaturing the innominate artery,
A, Plate 9, or either of those main arterial vessels (the right common
carotid and subclavian) which spring from it; and he will also observe
that, although the same number and kind of structures overlie the
carotid and subclavian vessels, A B, of the left side, Plate 10, still,
that these vessels themselves, in consequence of their separate
condition, will materially influence the like operation in respect to
them. An aneurism occurring in the first part of the course of the right
subclavian artery, at the locality a, Plate 9, will lie so close to the
origin of the right common carotid as to require a ligature to be passed
around the innominate common trunk, thus cutting off the flow of blood
from both vessels; whereas an aneurism implicating either the left
common carotid at the point A, or the left subclavian artery at the
point B, does not, of course, require that both vessels should be
included in the same ligature. There seems to be, therefore, a greater
probability of effectually treating an aneurism of the left
brachio-cephalic vessels by ligature than attaches to those of the right
side; for if space between collateral branches, and also a lesser
caliber of arterial trunk, be advantages, allowing the ligature to hold
more firmly, then the vessels of the left side of the root of the neck
manifest these advantages more frequently than those of the right, which
spring from a common trunk. Whenever, therefore, the "peculiarity" of a
separate aortic origin of the right carotid and subclavian arteries
occurs, it is to be regarded more as a happy advantage than otherwise.
DESCRIPTION OF PLATES 9 & 10.
PLATE 9.
A. Innominate artery, at its point of bifurcation.
B. Right internal jugular vein, joining the subclavian vein.
C. Sternal end of the right clavicle.
D. Trachea.
E. Right sterno-thyroid muscle, cut.
F. Right sterno-hyoid muscle, cut.
G. Right sterno-mastoid muscle, cut.
a. Right vagus nerve, crossing the subclavian artery.
b. Anterior jugular vein, piercing the cervical fascia to join the
subclavian vein.
[Illustration: Neck and upper chest, showing blood vessels, muscles and
other internal organs.]
Plate 9
PLATE 10.
A. Common carotid artery of left side.
B. Left subclavian artery, having b, the vagus nerve, between it and A.
C. Lower end of left internal jugular vein, joining--
D. Left subclavian vein, which lies anterior to d, the scalenus anticus
muscle.
E. Anterior jugular vein, coursing beneath sterno-mastoid muscle and
over the fascia.
F. Deep cervical fascia, enclosing in its layers f f f, the several
muscles.
G. Left sterno-mastoid muscle, cut across, and separated from g g, its
sternal and clavicular attachments.
H. Left sterno-hyoid muscle, cut.
I. Left sterno-thyroid muscle, cut.
K. Right sterno-hyoid muscle.
L. Right sterno-mastoid muscle.
M. Trachea.
N. Projection of the thyroid cartilage.
O. Place of division of common carotid.
P. Place where the subclavian artery passes beneath the clavicle.
Q. Sternal end of the left clavicle.
[Illustration: Neck and upper chest, showing blood vessels, muscles and
other internal organs.]
Plate 10
COMMENTARY ON PLATES 11 & 12.
THE SURGICAL DISSECTION OF THE AXILLARY AND BRACHIAL REGIONS,
DISPLAYING THE RELATIVE ORDER OF THEIR CONTAINED PARTS.
All surgical regions have only artificial boundaries; and these, as
might be expected, do not express the same meaning while viewed from
more points than one. These very boundaries themselves, being moveable
parts, must accordingly influence the relative position of the
structures which they bound, and thus either include within or exclude
from the particular region those structures wholly or in part which are
said to be proper to it. Of this kind of conventional surgical boundary
the moveable clavicle is an example; and the bloodvessels which it
overarches manifest consequently neither termination nor origin except
artificially from the fixed position which the bone, R, assumes, as in
Plate 11, or c*, Plate 12. In this position of the arm in relation to
the trunk, the subclavian artery, B, terminates at the point where,
properly speaking, it first takes its name; and from this point to the
posterior fold of the axilla formed by the latissimus dorsi muscle, O,
Plate 11, N, Plate 12, and the anterior fold formed by the great
pectoral muscle, K, Plate 11, I, Plate 12, the continuation of the
subclavian artery is named axillary. From the posterior fold of the
axilla, O P, Plate 11, to the bend of the elbow, the same main vessels
take the name of brachial.
When the axillary space is cut into from the forepart through the great
pectoral muscle, H K, Plate 11, and beneath this through the lesser
pectoral muscle, L I, together with the fascial processes which invest
these muscles anteriorly and posteriorly, the main bloodvessels and
nerves which traverse this space are displayed, holding in general that
relative position which they exhibit in Plate 11. These vessels, with
their accompanying nerves, will be seen continued from those of the
neck; and thus may be attained in one view a comparative estimate of the
cervical and axillary regions, together with their line of union beneath
the clavicle, c*, Plate 12, R, Plate 11, which serves to divide them
surgically.
In the neck, the subclavian artery, B, Plate 11, is seen to be separated
from the subclavian vein, A, by the breadth of the anterior scalenus
muscle, D, as the vessels arch over the first rib, F. In this region of
the course of the vessels, the brachial plexus of nerves, C, ranges
along the outer border of the artery, B, and is separated by the artery
from the vein, A, as all three structures pass beneath the clavicle, R,
and the subclavius muscle, E. From this latter point the vessels and
nerves take the name axillary, and in this axillary region the relative
position of the nerves and vessels to each other and to the adjacent
organs is somewhat changed. For now in the axillary region the vein, a,
is in direct contact with the artery, b, on the forepart and somewhat to
the inner side of which the vein lies; while the nerves, D, d, Plate 12,
embrace the artery in a mesh or plexus of chords, from which it is often
difficult to extricate it, for the purpose of ligaturing, in the dead
subject, much less the living. The axillary plexus of nerves well merits
the name, for I have not found it in any two bodies assuming a similar
order or arrangement. Perhaps the order in which branches spring from
the brachial plexus that is most constantly met with is the one
represented at D, Plate 12, where we find, on the outer border of B, the
axillary artery, a nervous chord, d, giving off a thoracic branch to
pass behind H, the lesser pectoral muscle, while the main chord itself,
d, soon divides into two branches, one the musculo-cutaneous, e, which
pierces G, the coraco-brachialis muscle, and the other which forms one
of the roots of the median nerve, h. Following that order of the nerves
as they are shown in Plate 12, they may be enumerated from without
inwards as follows:--the external or musculo-cutaneous, e; the two roots
of the median, h; the ulnar, f; the musculo-spiral, g; the circumflex,
i; close to which are seen the origins of the internal cutaneous, the
nerve of Wrisberg, some thoracic branches, and posteriorly the
subscapular nerve not seen in this view of the parts.
The branches which come off from the axillary artery are very variable
both as to number and place of origin, but in general will be found
certain branches which answer to the names thoracic, subscapular, and
circumflex. These vessels, together with numerous smaller arteries,
appear to be confined to no fixed point of origin, and on this account
the place of election for passing a ligature around the main axillary
artery sufficiently removed from collateral branches must be always
doubtful. The subscapular artery, Q, Plate 12, is perhaps of all the
other branches that one which manifests the most permanent character;
its point of origin being in general opposite the interval between the
latissimus and sub-scapular muscles, but I have seen it arise from all
parts of the axillary main trunk. If it be required to give, in a
history of the arteries, a full account of all the deviations from the
so-called normal type to which these lesser branches here and elsewhere
are subject, such account can scarcely be said to be called for in this
place.
The form of the axillary space is conical, while the arm is abducted
from the side, and while the osseous and muscular structures remain
entire. The apex of the cone is formed at the root of the neck beneath
the clavicle, R, Plate 11, and the subclavious muscle, E, and between
the coracoid process, L*, of the scapula and the serratus magnus muscle,
as this lies upon the thoracic side; at this apex the subclavian
vessels, A B, enter the axillary space. The base of the cone is below,
looking towards the arm, and is formed in front by the pectoralis major,
K H, and behind by the latissimus dorsi, O, and teres muscles, P,
together with a dense thick fascia; at this base the axillary vessels, a
b, pass out to the arm, and become the brachial vessels, a*b*. The
anterior side of the cone is formed by the great pectoral muscle, H K,
Plate 11, and the lesser pectoral, L I. The inner side is formed by the
serratus magnus muscle, M, Plate 12, on the side of the thorax; the
external side is formed by the scapular and humeral insertion of the
subscapular muscle, the humerus and coraco-brachialis muscle; and the
posterior side is formed by the latissimus dorsi, the teres and body of
the subscapular muscle.
In this axillary region is contained a complicated mass of bloodvessels,
nerves, and lymphatic glands, surrounded by a large quantity of loose
cellular membrane and adipose tissue. All the arterial branches here
found are given off from the axillary artery; and the numerous veins
which accompany these branches enter the axillary vein. Nerves from
other sources besides those of the axillary plexus traverse the axillary
space; such nerves, for example, as those named intercosto-humeral, seen
lying on the latissimus tendon, O, Plate 11. The vein named cephalic, S,
enters the axillary space at that cellular interval occurring between
the clavicular origin of the deltoid muscle, G, and the humeral
attachment of the pectoralis major, H, which interval marks the place of
incision for tying the axillary artery.
The general course of the main vessels through the axillary space would
be indicated with sufficient accuracy by a line drawn from the middle of
the clavicle, R R, Plate 11, to the inner border of the biceps muscle,
N. In this direction of the axillary vessels, the coracoid process, L*,
from which arises the tendon of the pectoralis minor muscle, L, is to be
taken as a sure guide to the place of the artery, b, which passes, in
general, close to the inner side of this bony process. Even in the
undissected body the coracoid process may be felt as a fixed resisting
point at that cellular interval between the clavicular attachments of
the deltoid and great pectoral muscles. Whatever necessity shall require
a ligature to be placed around the axillary in preference to the
subclavian artery, must, of course, be determined by the particular
case; but certain it is that the main artery, at the place B, a little
above the clavicle, will always be found freer and more isolated from
its accompanying nerves and vein, and also more easily reached, owing to
its comparatively superficial situation, than when this vessel has
become axillary. The incision required to be made, in order to reach the
axillary artery, b, from the forepart, through the skin, both pectoral
muscles, and different layers of fasciae, must be very deep, especially
in muscular, well-conditioned bodies; and even when the level of the
vessel is gained, it will be found much complicated by its own branches,
some of which overlie it, as also by the plexus of nerves, D, Plate 12,
which embraces it on all sides, while the large axillary vein, a, Plate
11, nearly conceals it in front. This vein in Plate 11 is drawn somewhat
apart from the artery.
Sometimes the axillary artery is double, in consequence of its high
division into brachial branches. But as this peculiarity of premature
division never takes place so high up as where the vessel, B, Plate 11,
overarches the first rib, F, this circumstance should also have some
weight with the operator.
When we view the relative position of the subclavian vessels, A B, Plate
11, to the clavicle, R, we can readily understand why a fracture of the
middle of this bone through that arch which it forms over the vessels,
should interfere with the free circulation of the blood which these
vessels supply to the arm. When the clavicle is severed at its middle,
the natural arch which the bone forms over the vessels and nerves is
lost, and the free moving broken ends of the bone will be acted on in
opposing directions by the various muscles attached to its sternal and
scapular extremities. The outer fragment follows more freely than the
inner piece the action of the muscles; but, most of all, the weight of
the unsupported shoulder and arm causes the displacement to which the
outer fragment is liable. The subclavius muscle, E, like the pronator
quadratus muscle of the forearm, serves rather to further the
displacement of the broken ends of the bone than to hold them in situ.
If the head of the humerus be dislocated forwards beneath L, Plate 11,
the coracoid attachment of the pectoralis minor muscle, it must press
out of their proper place and put tensely upon the stretch the axillary
vessels and plexus of nerves. So large and resistent a body as the head
of the humerus displaced forwards, and taking the natural position of
these vessels and nerves, will accordingly be attended with other
symptoms--such as obstructed circulation and pain or partial paralysis,
besides those physical signs by which we distinguish the presence of it
as a new body in its abnormal situation.
When the main vessels and nerves pass from the axillary space to the
inner side of the arm, they become comparatively superficial in this
latter situation. The inner border of the biceps muscle is taken as a
guide to the place of the brachial artery for the whole extent of its
course in the arm. In plate 11, the artery, b*, is seen in company with
the median nerve, which lies on its fore part, and with the veins called
comites winding round it and passing with it and the nerve beneath the
fascia which encases in a fold of itself all three structures in a
common sheath. Though the axillary vein is in close contact with the
axillary artery and nerves, yet the basilic vein, d*, the most
considerable of those vessels which form the axillary vein, is separated
from the brachial artery by the fascia. The basilic vein, however,
overlies the brachial artery to its inner side, and is most commonly
attended by the internal cutaneous nerve, seen lying upon it in Plate
11, as also by that other cutaneous branch of the brachial plexus, named
the nerve of Wrisberg. If a longitudinal incision in the course of the
brachial artery be made (avoiding the basilic vein) through the
integument down to the fascia of the arm, and the latter structure be
slit open on the director, the artery will be exposed, having the median
nerve lying on its outer side in the upper third of the arm, and passing
to its inner side towards the bend of the elbow, as at b*, Plate 12. The
superior and inferior profunda arteries, seen springing above and below
the point b, Plate 12, are those vessels of most importance which are
given off from the brachial artery, but the situation of their origin is
very various. The ulnar nerve, f, lies close to the inner side of the
main arterial trunk, as this latter leaves the axilla, but from this
place to the inner condyle, Q, behind which the ulnar nerve passes into
the forearm, the nerve and artery become gradually more and more
separated from each other in their descent. The musculo-spiral nerve, g,
winds under the brachial artery at the middle of the arm, but as this
nerve passes deep between the short and long heads of the triceps
muscle, P, and behind the humerus to gain the outer aspect of the limb,
a little care will suffice for avoiding the inclusion of it in the
ligature.
The brachial artery may be so effectually compressed by the fingers on
the tourniquet, against the humerus in any part of its course through
the arm, as to stop pulsation at the wrist.
The tourniquet is a less manageable and not more certain compressor of
the arterial trunk than is the hand of an intelligent assistant. At
every region of the course of an artery where the tourniquet is
applicable, a sufficient compression by the hand is also attainable with
greater ease to the patient; and the hand may compress the vessel at
certain regions where the tourniquet would be of little or no use, or
attended with inconvenience, as in the locality of the subclavian
artery, passing over the first rib, or the femoral artery, passing over
the pubic bone, or the carotid vessels in the neighbourhood of the
trachea, as they lie on the fore part of the cervical spinal column.
DESCRIPTION OF PLATES 11 & 12.
PLATE 11.
A. Subclavian vein, crossed by a branch of the brachial plexus given to
the subclavius muscle; a, the axillary vein; a *, the basilic vein,
having the internal cutaneous nerve lying on it.
B. Subclavian artery, lying on F, the first rib; b, the axillary artery;
b *, the brachial artery, accompanied by the median nerve and venae
comites.
C. Brachial plexus of nerves; c*, the median nerve.
D. Anterior scalenus muscle.
E. Subclavius muscle.
F F. First rib.
G. Clavicular attachment of the deltoid muscle.
H. Humeral attachment of the great pectoral muscle.
I. A layer of fascia, encasing the lesser pectoral muscle.
K. Thoracic half of the great pectoral muscle.
L. Coracoid attachment of the lesser pectoral muscle.
L*. Coracoid process of the scapula.
M. Coraco-brachialis muscle.
N. Biceps muscle.
O. Tendon of the latissimus dorsi muscle, crossed by the
intercosto-humeral nerves.
P. Teres major muscle, on which and O is seen lying Wrisberg's nerve.
Q. Brachial fascia, investing the triceps muscle. .
R R. Scapular and sternal ends of the clavicle.
S. Cephalic vein, coursing between the deltoid and pectoral muscles, to
enter at their cellular interval into the axillary vein beneath E, the
subclavius muscle.
[Illustration: Right arm and upper chest, showing blood vessels, muscles
and other internal organs.]
Plate 11
PLATE 12.
A. Axillary vein, cut and tied; a, the basilic vein, cut.
B. Axillary artery; b, brachial artery, in the upper part of its course,
having h, the median nerve, lying rather to its outer side; b*, the
artery in the lower part of its course, with the median nerve to its
inner side.
C. Subclavius muscle.
C*. Clavicle.
D. Axillary plexus of nerves, of which d is a branch on the coracoid
border of the axillary artery; e, the musculo-cutaneous nerve, piercing
the coraco-brachialis muscle; f, the ulnar nerve; g, musculo-spiral
nerve; h, the median nerve; i, the circumflex nerve.
E. Humeral part of the great pectoral muscle.
F. Biceps muscle.
G. Coraco-brachialis muscle.
H. Thoracic half of the lesser pectoral muscle.
I. Thoracic half of the greater pectoral muscle.
K. Coracoid attachment of the lesser pectoral muscle.
K*. Coracoid process of the scapula.
L. Lymphatic glands.
M. Serratus magnus muscle.
N. Latissimus dorsi muscle.
O. Teres major muscle.
P. Long head of triceps muscle.
Q. Inner condyle of humerus.
[Illustration: Right arm, showing blood vessels, muscles and other
internal organs.]
Plate 12
COMMENTARY ON PLATES 13 & 14.
THE SURGICAL FORM OF THE MALE AND FEMALE AXILLAE COMPARED.
Certain characteristic features mark those differences which are to be
found in all corresponding regions of both sexes. Though the male and
female bodies, in all their regions, are anatomically homologous or
similar at basis, yet the constituent and corresponding organs of each
are gently diversified by the plus or minus condition, the more or the
less, which the development of certain organs exhibits; and this
diversity, viewed in the aggregate, constitutes the sexual difference.
That diversity which defines the sexual character of beings of the same
species, is but a link in that extended chain of differential gradation
which marks its progress through the whole animal kingdom. The female
breast is a plus glandular organ, situated, pendent, in that very
position where, in a male body, the unevolved mamma is still
rudimentarily manifested.
The male and female axillae contain the same number and species of
organs; and the difference by which the external configuration of both
are marked mainly arises from the presence of the enlarged mammary
gland, which, in the female, Plate 14, masks the natural outline of the
pectoral muscle, E, whose axillary border is overhung by the gland; and
thus this region derives its peculiarity of form, contrasted with that
of the male subject.
When the dissected axilla is viewed from below, the arm being raised,
and extended from the side, its contained parts, laid deeply in their
conical recess, are sufficiently exposed, at the same time that the
proper boundaries of the axillary cavity are maintained. In this point
of view from which the axillary vessels are now seen, their relative
position, in respect to the thorax and the arm, are best displayed. The
thickness of that fleshy anterior boundary formed by both pectoral
muscles, E F, Plate 13, will be marked as considerable; and the depth at
which these muscles conceal the vessels, A B, in the front aspect of the
thoracico-humeral interval, will prepare the surgeon for the
difficulties he is to encounter when proceeding to ligature the axillary
artery at the incision made through the anterior or pectoral wall of
this axillary space.
The bloodvessels of the axilla follow the motions of the arm; and
according to the position assumed by the arm, these vessels describe
various curves, and lie more or less removed from the side of the
thorax. While the arm hangs close to the side, the axillary space does
not (properly speaking) exist; and in this position, the axillary
vessels and nerves make a general curve from the clavicle at the point
K, Plate 14, to the inner side of the arm, the concavity of the curve
being turned towards the thoracic side. But when the arm is abducted
from the side, and elevated, the vessels which are destined to supply
the limb follow it, and in this position they take, in reality, a
serpentine course; the first curve of which is described, in reference
to the thorax, from the point K to the head of the humerus; and the next
is that bend which the head of the humerus, projecting into the axilla
in the elevated position of the member, forces them to make around
itself in their passage to the inner side of the arm. The vessels may be
readily compressed against the upper third of the humerus by the finger,
passed into the axilla, and still more effectually if the arm be raised,
as this motion will rotate the tuberous head of the humerus downwards
against them.
The vessels and nerves of the axilla are bound together by a fibrous
sheath derived from the membrane called costo-coracoid; and the base or
humeral outlet of this axillary space, described by the muscles C, K, E,
G, Plate 13, is closed by a part of the fascial membrane, g, extended
across from the pectoral muscle, E, to the latissimus dorsi tendon, K.
In the natural position of the vessels at that region of their course
represented in the Plates, the vein A overlies the artery B, and also
conceals most of the principal nerves. In order to show some of these
nerves, in contact with the artery itself, the axillary vein is drawn a
little apart from them.
The axillary space gives lodgment to numerous lymphatic glands, which
are either directly suspended from the main artery, or from its
principal branches, by smaller branches, destined to supply them. These
glands are more numerous in the female axilla, Plate 14, than in the
male, Plate 13, and while they seem to be, as it were, indiscriminately
scattered here and there through this region, we observe the greater
number of them to be gathered together along the axillary side of the
great pectoral muscle; at which situation, h, in the diseased condition
of the female breast, they will be felt to form hard, nodulated masses,
which frequently extend as far up through the axillary space as the root
of the neck, involving the glands of this latter region also in the
disease.
The contractile motions of the pectoral muscle, E, of the male body,
Plate 13, are during life readily distinguishable; and that boundary
which it furnishes to the axillary region is well defined; but in the
female form, Plate 14, the general contour of the muscle E, while in
motion, is concealed by the hemispherical mammary gland, F, which,
surrounded by its proper capsule, lies loosely pendent from the fore
part of the muscle, to which, in the healthy state of the organ, it is
connected only by free-moving bonds of lax cellular membrane. The
motions of the shoulder upon the trunk do not influence the position of
the female mammary gland, for the pectoral muscle acts freely beneath
it; but when a scirrhus or other malignant growth involves the mammary
organ, and this latter contracts, by the morbid mass, a close adhesion
to the muscle, then these motions are performed with pain and
difficulty.
When it is required to excise the diseased female breast, (supposing the
disease to be confined to the structure of the gland itself,) the
operation may be performed confidently and without difficulty, in so far
as the seat of operation does not involve the immediate presence of any
important nerves or bloodvessels. But when the disease has extended to
the axillary glands, the extirpation of these (as they lie in such close
proximity to the great axillary vessels and their principal branches)
requires cautious dissection. It has more than once happened to eminent
surgeons, that in searching for and dissecting out these diseased
axillary glands, H, h, Plate 14, the main artery has been wounded.
As the coracoid process points to the situation of the artery in the
axilla, so the coraco-brachialis muscle, C, marks the exact locality of
the vessel as it emerges from this region; the artery ranges along the
inner margin of both the process and the muscle, which latter, in fleshy
bodies, sometimes overhangs and conceals it. When the vessel has passed
the insertion of the coraco-brachialis, it becomes situated at the inner
side of the biceps, which also partly overlaps it, as it now lies on the
forepart of the brachialis anticus. As the general course of the
artery, from where it leaves the axilla to the bend of the elbow, is one
of winding from the inner side to the forepart of the limb, so should
compression of the vessel, when necessary, be directed in reference to
the bone accordingly--viz., in the upper or axillary region of the arm,
from within outwards, and in the lower part of the arm, from before
backwards.
All incised, lacerated, or contused wounds of the arm and shoulder,
happening by pike, bayonet, sabre, bullet, mace, or arrow, on the outer
aspect of the limb, are (provided the weapon has not broken the bones)
less likely to implicate the great arteries, veins, and nerves. These
instruments encountering the inner or axillary aspect of the member,
will of course be more likely to involve the vessels and nerves in the
wound. In severe compound fractures of the humerus occurring from force
applied at the external side of the limb, the brachial vessels and
nerves have been occasionally lacerated by the sharp jagged ends of the
broken bone,--a circumstance which calls for immediate amputation of the
member.
The axilla becomes very frequently the seat of morbid growths, which,
when they happen to be situated beneath the dense axillary fascia, and
have attained to a large size, will press upon the vessels and nerves of
this region, and cause very great inconvenience. Adipose and other kind
of tumours occurring in the axilla beneath the fascia, and in close
contact with the main vessels, have been known to obstruct these vessels
to such a degree, as to require the collateral or anastomatic
circulation to be set up for the support; of the limb. When abscesses
take place in the axilla, beneath the fascia, it is this structure which
will prevent the matter from pointing; and it is required, therefore, to
lay this fascia freely open by a timely incision. The accompanying
Plates will indicate the proper direction in which such incision should
be made, so as to avoid the vessels A, B. When the limb is abducted from
the side, the main vessels and nerves take their position parallel with
the axis of the arm. The axillary vessels and nerves being thus liable
to pressure from the presence of large tumours happening in their
neighbourhood, will suggest to the practitioner the necessity for
fashioning of a proper form and size all apparatus, which in fracture or
dislocation of the shoulder-bones shall be required to bear forcibly
against the axillary region. While we know that the locality of the main
vessels and nerves is that very situation upon which a pad or fulcrum
presses, when placed in the axilla for securing the reduction of
fractures of the clavicle, the neck of the humerus, or scapula, so
should this member of the fracture apparatus be adapted, as well to
obviate this pressure upon these structures, as to give the needful
support to the limb in reference to the clavicle, &c. The habitual use,
for weeks or more, of a hard, resisting fulcrum in the axilla, must act
in some degree like the pad of a tourniquet, arresting the flow of a
vigorous circulation, which is so essential to the speedy union of all
lesions of bones. And it should never be lost sight of, that all
grievously coercive apparatus, which incommode the suffering patient,
under treatment, are those very instruments which impede the curative
process of Nature herself.
The anatomical mechanism of the human body, considered as a whole, or
divisible into regions, forms a study so closely bearing upon practice,
that the surgeon, if he be not also a mechanician, and fully capable of
making his anatomical knowledge suit with the common principles of
mechanics, while devising methods for furthering the efforts, of Nature
curatively, may be said to have studied anatomy to little or no purpose.
The shoulder apparatus, when studied through the principle of mechanics,
derives an interest of practical import which all the laboured
description of the schools could never supply to it, except when
illustrating this principle.
The disposal of the muscular around the osseous elements of the shoulder
apparatus, forms a study for the surgeon as well in the abnormal
condition of these parts, as in their normal arrangement; for in
practice he discovers that that very mechanical principle upon which
both orders of structures (the osseous and muscular) are grouped
together for normal articular action, becomes, when the parts are
deranged by fracture or, other accident, the chief cause whereby
rearrangement is prevented, and the process of reunion obstructed. When
a fracture happens in the shaft of the humerus, above or below the
insertions of the pectoral and latissimus dorsi muscles, these are the
very agents which when the bone possessed its integrity rendered it
functionally fitting, and which, now that the bone is severed, produce
the displacement of the lower fragment from the upper one. To counteract
this source of derangement, the surgeon becomes the mechanician, and
now, for the first time, he recognises the necessity of the study of
topographical anatomy.
When a bone is fractured, or dislocated to a false position and retained
there by the muscular force, the surgeon counteracts this force upon
mechanical principle; but while he puts this principle in operation, he
also acknowledges to the paramount necessity of ministering to the ease
of Nature as much as shall be consistent with the effectual use of the
remedial agent; and in the present state of knowledge, it is owned, that
that apparatus is most efficient which simply serves both objects, the
one no less than the other. And, assuming this to be the principle which
should always guide us in our treatment of fractures and dislocations, I
shall not hesitate to say, that the pad acting as a fulcrum in the
axilla, or the perineal band bearing as a counterextending force upon
the groin (the suffering body of the patient being, in both instances,
subjected for weeks together to the grievous pressure and irritation of
these members of the apparatus), do not serve both objects, and only one
incompletely; I say incompletely, for out of every six fractures of
either clavicle or thigh-bone, I believe that, as the result of our
treatment by the present forms of mechanical contrivances, there would
not be found three cases of coaptation of the broken ends of the bone so
complete as to do credit to the surgeon. The most pliant and portable of
all forms of apparatus which constitute the hospital armamentaria, is
the judgment; and this cannot give its approval to any plan of
instrument which takes effect only at the expense of the patient.
DESCRIPTION OF PLATES 13 & 14.
PLATE 13.
A. Axillary vein, drawn apart from the artery, to show the nerves lying
between both vessels. On the bicipital border of the vein is seen the
internal cutaneous nerve; on the tricipital border is the nerve of
Wrisberg, communicating with some of the intercosto-humeral nerves; a,
the common trunk of the venae comites, entering the axillary vein.
B. Axillary artery, crossed by one root of the median nerve; b, basilic
vein, forming, with a, the axillary vein, A.
C. Coraco-brachialis muscle.
D. Coracoid head of the biceps muscle.
E. Pectoralis major muscle.
F. Pectoralis minor muscle.
G. Serratus magnus muscle, covered by g, the axillary fascia, and
perforated, at regular intervals, by the nervous branches called
intercosto-humeral.
H. Conglobate gland, crossed by the nerve called "external respiratory"
of Bell, distributed to the serratus magnus muscle. This nerve descends
from the cervical plexus.
I. Subscapular artery.
K. Tendon of latissimus dorsi muscle.
L. Teres major muscle.
[Illustration: Arm and chest, showing blood vessels, muscles and other
internal organs.]
Plate 13
PLATE 14.
A. Axillary vein.
B. Axillary artery.
C. Coraco-brachialis muscle.
D. Short head of the biceps muscle.
E. Pectoralis major muscle.
F. Mammary gland, seen in section.
G. Serratus magnus muscle.
H. Lymphatic gland; h h, other glands of the lymphatic class.
I. Subscapular artery, crossed by the intercosto-humeral nerves and
descending parallel to the external respiratory nerve. Beneath the
artery is seen a subscapular branch of the brachial plexus, given
to the latissimus dorsi muscle.
K. Locality of the subclavian artery.
L. Locality of the brachial artery at the bend of the elbow.
[Illustration: Arm and chest, showing blood vessels, muscles and other
internal organs.]
Plate 14
COMMENTARY ON PLATES 15 & 16.
THE SURGICAL DISSECTION OF THE BEND OF THE ELBOW
AND THE FOREARM, SHOWING THE RELATIVE POSITION
OF THE ARTERIES, VEINS, NERVES, &c.
The farther the surgical region happens to be removed from the centre of
the body, the less likely is it that all accidents or operations which
involve such regions will concern the life immediately. The limbs
undergo all kinds of mutilation, both by accident and intention, and yet
the patient survives; but when the like happens at any region of the
trunk of the body, the life will be directly and seriously threatened.
It seems, therefore, that in the same degree as the living principle
diverges from the body's centre into the outstanding members, in that
degree is the life weakened in intensity; and just as, according to
physical laws, the ray of light becomes less and less intense by the
square of the distance from the central source, so the vital ray, or
vis, loses momentum in the same ratio as it diverges from the common
central line to the periphery.
The relative anatomy of every surgical region becomes a study of more or
less interest to the surgeon, according to the degree of importance
attaching to the organs contained, or according to the frequency of such
accidents as are liable to occur in each. The bend of the elbow is a
region of anatomical importance, owing to the fact of its giving passage
to C, Plate 15, the main artery of the limb, and also because in it are
located the veins D, B, E, F, which are frequently the subject of
operation. The anatomy of this region becomes, therefore, important;
forasmuch as the operation which is intended to concern the veins alone,
may also, by accident, include the main arterial vessel which they
overlie. The nerves, which are seen to accompany the veins
superficially, as well as that which accompanies the more
deeply-situated artery, are, for the same reason, required to be known.
The course of the brachial artery along the inner border of the biceps
muscle is comparatively superficial, from the point where it leaves the
axilla to the bend of the elbow. In the whole of this course it is
covered by the fascia of the arm, which serves to isolate it from the
superficial basilic vein, B, and the internal cutaneous nerve, both of
which nevertheless overlie the artery. The median nerve, d, Plate 15,
accompanies the artery in its proper sheath, which is a duplication of
the common fascia; and in this sheath are also situated the venae
comites, making frequent loops around the artery. The median nerve
itself, D, Plate 16, takes a direct course down the arm; and the
different relative positions which this nerve holds in reference to the
artery, C, at the upper end, the middle, and the lower end of the arm,
occur mainly in consequence of the undulating character of the vessel
itself.
When it is required to ligature the artery in the middle of the arm, the
median nerve will be found, in general, at its outer side, between it
and the biceps; but as the course of the artery is from the inner side
of the biceps to the middle of the bend of the elbow, so we find it
passing under the nerve to gain this locality, C, Plate 16, where the
median nerve, D, then becomes situated at the inner side of the vessel.
The median nerve, thus found to be differently situated in reference to
the brachial artery, at the upper, the middle, and the lower part of the
arm, is (with these facts always held in memory) taken as the guide to
that vessel. An incision made of sufficient length (an inch and a half,
more or less) over the course of the artery, and to the outer side of
the basilic vein, B, Plate 16, will divide the skin, subcutaneous
adipose membrane, which varies much in thickness in several individuals,
and will next expose the common fascial envelope of the arm. When this
fascia is opened, by dividing it on the director, the artery becomes
exposed; the median nerve is then to be separated from the side of the
vessel by the probe or director, and, with the precaution of not
including the venal comites, the ligature may now be passed around the
vessel. In the lower third of the arm it is not likely that the operator
will encounter the ulnar nerve, and mistake it for the median, since the
former, d, Plate 16, is considerably removed from the vessel. If the
incision be made precisely in the usual course of the brachial artery,
the ulnar nerve will not show itself. It will be well, however, to bear
in mind the possible occurrence of some of those anomalies to that
normal relative position of the artery, the median, and the ulnar nerve,
which the accompanying Plates represent.
The median nerve, D, Plate 16, is sometimes found to lie beneath the
artery in the middle and lower third of the arm. At other times it is
found far removed to the inner side of the usual position of the vessel,
and lying in close contact with the ulnar nerve, d. Or the brachial
artery may take this latter position, while the median nerve stands
alone at the position of D, Plate 16. Or both the main artery and the
median nerve may course much to the inner side of the biceps muscle, A,
Plate 16, while in the usual situation of the nerve and vessel there is
only to be found a small arterial branch (the radial), which springs
from the brachial, high up in the arm. Or the nerve and vessel may be
lying concealed beneath a slip of the brachialis anticus muscle, E,
Plate 16, in which case no appearance of them will be at all manifested
through the usual place of incision made for the ligature of the
brachial vessel. Or, lastly, there may be found more arteries than the
single main brachial appearing at this place in the arm, and such
condition of a plurality of vessels occurs in consequence of a high
division of the brachial artery. Each of these variations from the
normal type is more or less frequent; and though it certainly is of
practical import to bear them in mind, still, as we never can foretell
their occurrence by a superficial examination of the limb, or pronounce
them to be present till we actually encounter them in operation, it is
only when we find them that we commence to reason upon the facts; but
even at this crisis the knowledge of their anatomy may prevent a
confusion of ideas.
That generalization of the facts of such anomalies as are liable to
occur to the normal character of the brachial artery, represented in
Plates 15 and 16, which appears to me as being most inclusive of all
their various conditions, is this--viz., that the point of division into
radial, ulnar, and interosseous, which F, Plate 16, usually marks, may
take place at any part of the member between the bend of the elbow and
the coracoid process in the axillary space.
At the bend of the elbow, the brachial artery usually occupies the
middle point between e, the inner condyle of the humerus and the
external margin of the supinator radii longus muscle, G. The structures
which overlie the arterial vessel, C, Plate 16, at this locality,
numbering them from its own depth to the cutaneous surface, are these--
viz., some adipose cellular membrane envelopes the vessel, as it lies on
E, the brachialis anticus muscle, and between the two accompanying
veins; at the inner side of the artery, but separated from it by a small
interval occupied by one of the veins, is situated the median nerve d,
Plate 15. Above all three structures is stretched that dense fibrous
band of the fascia, H, Plate 16, which becomes incorporated with the
common fascial covering of the forearm. Over this fascial process lies
the median basilic vein, F B, Plate 15, accompanying which are seen some
branches of the internal cutaneous nerve. The subcutaneous adipose
tissue and common integument cover these latter. If it be required to
ligature the artery at this locality, an incision two inches and a half
in length, made along the course of the vessel, and avoiding the
superficial veins, will expose the fascia; and this being next divided
on the director, the artery will be exposed resting on the brachialis
anticus, and between the biceps tendon and pronator teres muscle. As
this latter muscle differs in width in several individuals, sometimes
lying in close contact with the artery, and at other times leaving a
considerable interval between the vessel and itself, its outer margin is
not, therefore, to be taken as a sure guide to the artery. The inner
border of the biceps indicates much more generally the situation of the
vessel.
The bend of the elbow being that locality where the operation of
phlebotomy is generally performed, it is therefore required to take
exact account of the structures which occupy this region, and more
especially the relation which the superficial veins hold to the deeper
seated artery. In Plate 15, the artery, C, is shown in its situation
beneath the fascial aponeurosis, which comes off from the tendon of the
biceps, a portion of which has been cut away; and the venous vessel, F
B, which usually occupies the track of the artery, is pushed a little to
the inner side. While opening any part of the vessel, F B, which
overlies the artery, it is necessary to proceed with caution, as well
because of the fact that between the artery, C, and the vein, F B, the
fascia alone intervenes, as also because the ulnar artery is given off
rather frequently from the main vessel at this situation, and passes
superficial to the fascia and flexors of the forearm, to gain its usual
position at K, Plate 15. I have met with a well marked example of this
occurrence in the living subject.
The cephalic vein, D, is accompanied by the external cutaneous nerve,
which branches over the fascia on the outer border of the forearm. The
basilic vein, B, is accompanied by the internal cutaneous nerve, which
branches in a similar way over the fascia of the inner and fore part of
the forearm. The numerous branches of both these nerves interlace with
the superficial veins, and are liable to be cut when these veins are
being punctured. Though the median basilic, F, and the basilic vein, B,
are those generally chosen in the performance of the operation of
bleeding, it will be seen, in Plate 15, that their contiguity to the
artery necessarily demands more care and precision in that operation
executed upon them, than if D, the cephalic vein, far removed as it is
from the course of the artery, were the seat of phlebotomy.
As it is required, in order to distend the superficial veins, D, B, F,
that a band should be passed around the limb at some locality between
them and the heart, so that they may yield a free flow of blood on
puncture, a moderate pressure will be all that is needful for that end.
It is a fact worthy of notice, that the excessive pressure of the
ligaturing band around the limb at A B, Plate 15, will produce the same
effect upon the veins near F, as if the pressure were defective, for in
the former case the ligature will obstruct the flow of blood through the
artery; and the vein, F, will hence be undistended by the recurrent
blood, just as when, in the latter case, the ligature, making too feeble
a pressure on the vein, B, will not obstruct its current in that degree
necessary to distend the vessel, F.
Whichever be the vein chosen for phlebotomy at the bend of the elbow, it
will be seen, from an examination of Plates 15 and 16, that the opening
may be made with most advantage according to the longitudinal axis of
the vessel; for the vessel while being cut open in this direction, is
less likely to swerve from the point of the lancet than if it were to be
incised across, which latter mode is also far more liable to implicate
the artery. Besides, as the nerves course along the veins from above
downwards--making, with each other, and with the vessels, but very acute
angles--all incisions made longitudinally in these vessels, will not be
so likely to divide any of these nerves as when the instrument is
directed to cut crossways.
The brachial artery usually divides, at the bend of the elbow, into the
radial, the ulnar, and the interosseous branches. The point F, Plate 16,
is the common place of division, and this will be seen in the Plate to
be somewhat below the level of the inner condyle, e. From that place,
where the radial and ulnar arteries spring, these vessels traverse the
forearm, in general under cover of the muscles and fascia, but
occasionally superficial to both these structures. The radial artery, F
N, Plate 16, takes a comparatively superficial course along the radial
border of the forearm, and is accompanied, for the upper two-thirds of
its length, by the radial branch of the musculo-spiral nerve, seen in
Plate 16, at the outer side of the vessel. The supinator radii longus
muscle in general overlaps, with its inner border, both the radial
artery and nerve. At the situation of the radial pulse, I, Plate 15, the
artery is not accompanied by the nerve, for this latter will be seen, in
plate 16, to pass outward, under the tendon of the supinator muscle, to
the integuments.
The ulnar artery, whose origin is seen near F, Plate 16, passes deeply
beneath the superficial flexor muscles, L M K, and the pronator teres,
I, and first emerges from under cover of these at the point O, from
which point to S, Plate 16, the artery may be felt, in the living body,
obscurely beating as the ulnar pulse. On the inner border of the ulnar
artery, and in close connexion with it, the ulnar nerve may be seen
looped round by small branches of the vessel.
The radial and ulnar arteries may be exposed and ligatured in any part
of their course; but of the two, the radial vessel can be reached with
greater facility, owing to its comparatively superficial situation. The
inner border of the supinator muscle, G, Plate 16, is the guide to the
radial artery; and the outer margin of the flexor carpi ulnaris muscle,
K, Plate 16, indicates the locality of the ulnar artery. Both arteries,
I, K, Plate 15, at the wrist, lie beneath the fascia. If either of these
vessels require a ligature in this region of the arm, the operation may
be performed with little trouble, as a simple incision over the track of
the vessels, through the skin and the fascia, will readily expose each.
Whenever circumstances may call for placing a ligature on the ulnar
artery, as it lies between the superficial and deep flexor muscles, in
the region of I L M, Plate 16, the course of the vessel may be indicated
by a line drawn from a central point of the forearm, an inch or so below
the level of the inner condyle--viz., the point F, and carried to the
pisiform bone, T. The line of incision will divide obliquely the
superficial flexors; and, on a full exposure of the vessel in this
situation, the median nerve will be seen to cross the artery at an acute
angle, in order to gain the mid-place in the wrist at Q. The ulnar
nerve, d, Plate 16, passing behind the inner condyle, e, does not come
into connexion with the ulnar artery until both arrive at the place O.
It will, however, be considered an awkward proceeding to subject to
transverse section so large a mass of muscles as the superficial flexors
of the forearm, when the vessel may be more readily reached elsewhere,
and perhaps with equal advantage as to the locality of the ligature.
When either the radial or ulnar arteries happen to be completely divided
in a wound, both ends of the vessel will bleed alike, in consequence of
the free anastomosis of both arteries in the hand.
DESCRIPTION OF PLATES 15 & 16.
PLATE 15.
A. Fascia covering the biceps muscle.
B. Basilic vein, with the internal cutaneous nerve.
C. Brachial artery, with the venae comites.
D. Cephalic vein, with the external cutaneous nerve; d, the median nerve.
E. A communicating vein, joining the venae comites.
F. Median basilic vein.
G. Lymphatic gland.
H. Radial artery at its middle.
I. Radial artery of the pulse.
K. Ulnar artery, with ulnar nerve.
L. Palmaris brevis muscle.
[Illustration: Right arm, showing blood vessels, muscles and other
internal organs.]
Plate 15
PLATE 16.
A. Biceps muscle.
B. Basilic vein, cut.
C. Brachial artery.
D. Median nerve; d, the ulnar nerve.
E. Brachialis anticus muscle; e, the internal condyle.
F. Origin of radial artery.
G. Supinator radii longus muscle.
H. Aponeurosis of the tendon of the biceps muscle.
I. Pronator teres muscle.
K. Flexor carpi ulnaris muscle.
L. Flexor carpi radialis muscle.
M. Palmaris longus muscle.
N. Radial artery, at its middle, with the radial nerve on its outer side.
O. Flexor digitorum sublimis.
P. Flexor pollicis longus.
Q. Median nerve.
R. Lower end of radial artery.
S. Lower end of ulnar artery, in company with the ulnar nerve.
T. Pisiform bone.
U. Extensor metacarpi pollicis.
[Illustration: Right arm, showing blood vessels, muscles and other
internal organs.]
Plate 16
COMMENTARY ON PLATES 17, 18, & 19.
THE SURGICAL DISSECTION OF THE WRIST AND HAND.
A member of such vast importance as the human hand necessarily claims a
high place in regard to surgery. The hand is typical of the mind. It is
the material symbol of the immaterial spirit, It is the prime agent of
the will; and it is that instrument by which the human intellect
manifests its presence in creation. The human hand has a language of its
own. While the tongue demonstrates the thought through the word, the
hand realizes and renders visible the thought through the work. This
organ, therefore, by whose fitness of form the mind declares its own
entity in nature, by the invention and creation of the thing, which is,
as it were, the mind's autograph, claims a high interest in surgical
anatomy; and accordingly the surgeon lays it down as a rule, strictly to
be observed, that when this beautiful and valuable member happens to be
seriously mutilated, in any of those various accidents to which it is
exposed, the prime consideration should be, not as to the fact of how
much of its quantity or parts it can be deprived in operation, but
rather as to how little of its quantity should it be deprived, since no
mechanical ingenuity can fashion an apparatus, capable of supplying the
loss of a finger, or even of one of its joints.
The main blood vessels and nerves of the arm traverse the front aspect
of the wrist, and are distributed chiefly to supply the palmar surface
of the hand, since in the palm are to be found a greater variety and
number of structures than are met with on the back of the hand. The
radial artery, A, Plate 17, occupies (as its name indicates) the radial
border of the forepart of the wrist, and the ulnar artery, C, Plate 17,
occupies the ulnar border; both vessels in this region of their course
lie parallel to each other; both are comparatively superficial, but of
the two, the radial artery is the more superficial and isolated, and
thereby occasions the radial pulse. The anatomical situation of the
radial artery accounts for the fact, why the pulsation of this vessel is
more easily felt than that of the ulnar artery.
The radial vessel, A, Plate 17, at the wrist, is not accompanied by the
radial nerve; for this nerve, C, Plate 19, passes from the side of the
artery, at a position, C, Plate 19, varying from one to two or more
inches above the wrist, to gain the dorsal aspect of the hand. The ulnar
artery, C, Plate 17, is attended by the ulnar nerve, D, in the wrist,
and both these pass in company to the palm. The ulnar nerve, D E, lies
on the ulnar border of the artery, and both are in general to be found
ranging along the radial side of the tendon of the flexor carpi ulnaris
muscle, T, and the pisiform bone, G. The situation of the radial artery
is midway between the flexor carpi radialis tendon, I, and the outer
border of the radius. The deep veins, called comites, lie in close
connexion with the radial and ulnar arteries. When it is required to lay
bare the radial or ulnar artery, at the wrist, it will be sufficient for
that object to make a simple longitudinal incision (an inch or two in
length) over the course of the vessel A or C, Plate 17, through the
integument, and this incision will expose the fascia, which forms a
common investment for all the structures at this region. When this
fascia has been cautiously slit open on the director, the vessels will
come into view. The ulnar artery, however, lies somewhat concealed
between the adjacent muscles, and in order to bring this vessel fully
into view, it will be necessary to draw aside the tendon of the flexor
ulnaris muscle, T.
The radial artery, A, Plate 18, passes external to the radial border of
the wrist, beneath the extensor tendons, B, of the thumb; and after
winding round the head of the metacarpal bone of the thumb, as seen at
E, Plate 19, forms the deep palmar arch E, Plate 18. This deep palmar
arch lies close upon the forepart of the carpo-metacarpal joints; it
sends off branches to supply the deeply situated muscles, and other
structures of the palm; and from it are also derived other branches,
which pierce the interosseal spaces, and appear on the back of the hand,
Plate 19. The deep palmar arch, E, Plate 18, inosculates with a branch
of the ulnar artery, I, Plate 18, whilst its dorsal interosseal
branches, Plate 19, communicate freely with the dorsal carpal arch,
which is formed by a branch of the radial artery E, Plate 19, and the
terminal branch of the posterior interosseous vessel.
The ulnar artery, C, Plate 17, holds a direct and superficial course,
from the ulnar border of the forearm through the wrist; and still
remains superficial in the palm, where it forms the superficial palmar
arch, F. From this arch arise three or four branches of considerable
size, which are destined to supply the fingers. A little above the
interdigital clefts, each of these digital arteries divides into two
branches, which pass along the adjacent sides of two fingers--a mode of
distribution which also characterises the digital branches of the
median, b b, and ulnar nerves, e e. The superficial palmar arch of the
ulnar vessel anastomoses with the deep arch of the radial vessel. The
principal points of communication are, first, by the branch, (ramus
profundus,) I, Plate 18, which passes between the muscles of the little
finger to join the deep arch beneath the long flexor tendons. 2nd, by
the branch (superficialis volae) which springs from the radial artery,
A, Plate 17, and crosses the muscles of the ball of the thumb, to join
the terminal branch of the superficial arch, F, Plate 17. 3rd, by
another terminal branch of the superficial arch, which joins the
arteries of the thumb, derived from the radial vessel, as seen at e,
Plate 18.
The frequent anastomosis thus seen to take place between the branches of
the radial, the ulnar, and the interosseous arteries in the hand, should
be carefully borne in mind by the surgeon. The continuity of the three
vessels by anastomosis, renders it very difficult to arrest a
haemorrhage occasioned by a wound of either of them. It will be at once
seen, that when a haemorrhage takes place from any of these larger
vessels of the hand, the bleeding will not be commanded by the
application of a ligature to either the radial, the ulnar, or the
interosseous arteries in the forearm; and for this plain reason, viz.,
that though in the arm these arteries are separate, in the hand their
communication renders them as one.
If a haemorrhage therefore take place from either of the palmar vessels,
it will not be sufficient to place a ligature around the radial or the
ulnar artery singly, for if F, Plate 17, bleeds, and in order to arrest
that bleeding we tie the vessel C, Plate 17, still the vessel F will
continue to bleed, in consequence of its communication with the vessel
E, Plate 18, by the branch 1, Plate 18, and other branches above
mentioned. If E, Plate 18, bleeds, a ligature applied to the vessel A,
Plate 18, will not stop the flow of blood, because of the fact that E
anastomoses with G, by the branch I and other branches, as seen in
Plates 17 and 19.
Any considerable haemorrhage, therefore, which may be caused by a wound
of the superficial or deep palmar arches, or their branches, and which
we are unable to arrest by compression, applied directly to the patent
orifices of the vessel, will in general require that a ligature be
applied to both the radial and ulnar arteries at the wrist; and it
occasionally happens that even this proceeding will not stop the flow of
blood, for the interosseous arteries, which also communicate with the
vessels of the hand, may still maintain the current of circulation
through them. These interosseous arteries being branches of the ulnar
artery, and being given off from the vessel at the bend of the elbow, if
the bleeding be still kept up from the vessel wounded in the hand, after
the ligature of the ulnar and radial arteries is accomplished, are in
all probability the channels of communication, and in this case the
brachial artery must be tied. A consideration of the above mentioned
facts, proper to the normal distribution of the vessels of the upper
extremity, will explain to the practitioner the cause of the difficulty
which occasionally presents itself, as to the arrest of haemorrhage from
the vessels of the hand. In addition to these facts he will do well to
remember some other arrangements of these vessels, which are liable to
occur; and upon these I shall offer a few observations.
While I view the normal disposition of the arteries of the arm as a
whole, (and this view of the whole great fact is no doubt necessary, if
we would take within the span and compass of the reason, all the lesser
facts of which the whole is inclusive,) I find that as one main vessel
(the brachial) divides into three lesser branches, (the ulnar, radial
and interosseous,) so, therefore, when either of these three supplies
the haemorrhage, and any difficulty arises preventing our having access
at once to the open orifices of the wounded vessel, we can command the
flow of blood by applying a ligature to the main trunk--the brachial. If
this measure fail to command the bleeding, then we may conclude that the
wounded vessel (whichever it happen to be, whether the radial, the
ulnar, or the interosseous) arises from the brachial artery, higher up
in the arm than that place whereat we applied the ligature. To this
variety as to the place of origin, the ulnar, radial, and interosseous
arteries are individually liable.
Again, as the single brachial artery divides into the three arteries of
the forearm, and as these latter again unite into what may (practically
speaking) be termed a single vessel in the hand, in consequence of their
anastomosis, so it is obvious that in order to command a bleeding from
any of the palmar arteries, we should apply a ligature upon each of the
vessels of the forearm, or upon the single main vessel in the arm. When
the former proceeding fails, we have recourse to the latter, and when
this latter fails (for fail it will, sometimes,) we then reasonably
arrive at the conclusion that some one of the three vessels of the
forearm, springs higher up than the place of the ligature on the main
brachial vessel.
But however varied as to the normal locality of their origin, at the
bend of the elbow, these vessels of the forearm may at times manifest
themselves, still one point is quite fixed and certain, viz., that they
communicate with each other in the hand. Hence, therefore, it becomes
evident, that in order to command, at once and effectually, a bleeding,
either from the palmar arteries, or those of the forearm, we attain to a
more sure and successful result, the nearer we approach the
fountain-head and place a ligature on it--the brachial artery. It is
true that to stop the circulation through the main vessel of the limb,
is always attended with danger, and that such a proceeding is never to
be adopted but as the lesser one of two great hazards. It is also true
that to tie the main brachial artery for a haemorrhage of anyone of its
terminal branches, may be doing too much, while a milder course may
serve; or else that even our tying the brachial may not suffice, owing
to a high distribution of the vessels of the arm, in the axilla, above
the place of the ligature. Thus doubt as to the safest measure, viz.,
that which is sufficient and no more, enveils the proper place whereat
to apply a ligature on the principal vessel; but whatever be the doubt
as to this particular, there can be none attending the following rule of
conduct, viz., that in all cases of haemorrhage, caused by wounds of the
vessels of the upper limb, we should, if at all practicable, endeavour
to stop the flow of blood from the divided vessels in the wound itself,
by ligature or otherwise; and both ends of the divided vessel require to
be tied. Whenever this may be done, we need not trouble ourselves
concerning the anomaly in vascular distribution.
The superficial palmar arch, F, Plate 17, lies beneath the dense palmar
fascia; and whenever matter happens to be pent up by this fascia, and it
is necessary that an opening be made for its exit, the incision should
be conducted at a distance from the locality of the vessel. When matter
forms beneath the palmar fascia, it is liable, owing to the unyielding
nature of this fibrous structure, to burrow upwards into the forearm,
beneath the annular ligament D, Plates 17 and 18. All deep incisions
made in the median line of the forepart of the wrist are liable to wound
the median nerve B, Plate 17. When the thumb, together with its
metacarpal bone, is being amputated, the radial artery E, Plate 19,
which winds round near the head of that bone, may be wounded. It is
possible, by careful dissection, to perform this operation without
dividing the radial vessel.
DESCRIPTION OF PLATES 17, 18, & 19.
PLATE 17.
A. Radial artery.
B. Median nerve; b b b b, its branches to the thumb and fingers.
C. Ulnar artery, forming F, the superficial palmar arch.
D. Ulnar nerve; E e e, its continuation branching to the little and ring
fingers, &c.
G. Pisiform bone.
H. Abductor muscle of the little finger.
I. Tendon of flexor carpi radialis muscle.
K. Opponens pollicis muscle.
L. Flexor brevis muscle of the little finger.
M. Flexor brevis pollicis muscle.
N. Abductor pollicis muscle.
OOOO. Lumbricales muscles.
P P P P. Tendons of the flexor digitorum sublimis muscle.
Q. Tendon of the flexor longus pollicis muscle.
R. Tendon of extensor metacarpi pollicis.
S. Tendons of extensor digitorum sublimis; P P P, their digital
prolongations.
T. Tendon of flexor carpi ulnaris.
U. Union of the digital arteries at the tip of the finger.
[Illustration: Right hand, showing blood vessels, muscles and other
internal organs.]
Plate 17
PLATE 18.
A. Radial artery.
B. Tendons of the extensors of the thumb.
C. Tendon of extensor carpi radialis.
D. Annular ligament.
E. Deep palmar arch, formed by radial artery giving off e, the artery of
the thumb.
F. Pisiform bone.
G. Ulnar artery, giving off the branch I to join the deep palmar arch E
of the radial artery.
H. Ulnar nerve; h, superficial branches given to the fingers. Its deep
palmar branch is seen lying on the interosseous muscles, M M.
K. Abductor minimi digiti.
L. Flexor brevis minimi digiti.
M. Palmar interosseal muscles.
N. Tendons of flexor digitorum sublimis and profundus, and the
lumbricales muscles cut and turned down.
O. Tendon of flexor pollicis longus.
P. Carpal end of the metacarpal bone of the thumb.
[Illustration: Left hand, showing blood vessels, muscles and other
internal organs.]
Plate 18
PLATE 19.
AAA. Tendons of extensor digitorum communis; A*, tendon overlying that
of the indicator muscle.
B. Dorsal part of the annular ligament.
C. End of the radial nerve distributed over the back of the hand, to two
of the fingers and the thumb.
D. Dorsal branch of the ulnar nerve supplying the back of the hand and
the three outer fingers.
E. Radial artery turning round the carpal end of the metacarpal bone of
the thumb.
F. Tendon of extensor carpi radialis brevis.
G. Tendon of extensor carpi radialis longus.
H. Tendon of third extensor of the thumb.
I. Tendon of second extensor of the thumb.
K. Tendon of extensor minimi digiti joining a tendon of extensor
communis.
[Illustration: Right hand, showing blood vessels, muscles and other
internal organs.]
Plate 19
COMMENTARY ON PLATES 20 & 21.
THE RELATIVE POSITION OF THE CRANIAL,
NASAL, ORAL, AND PHARYNGEAL CAVITIES, &c.
On making a section (vertically through the median line) of the
cranio-facial and cervico-hyoid apparatus, the relation which these
structures bear to each other in the osseous skeleton reminds me
strongly of the great fact enunciated by the philosophical anatomists,
that the facial apparatus manifests in reference to the cranial
structures the same general relations which the hyoid apparatus bears to
the cervical vertebrae, and that these relations are similar to those
which the thoracic apparatus bears to the dorsal vertebrae. To this
anatomical fact I shall not make any further allusions, except in so far
as the acknowledgment of it shall serve to illustrate some points of
surgical import.
The cranial chamber, A A H, Plate 20, is continuous with the spinal
canal C. The osseous envelope of the brain, called calvarium, Z B, holds
serial order with the cervical spinous processes, E I, and these with
the dorsal spinous processes. The dura-matral lining membrane, A A A*,
of the cranial chamber is continuous with the lining membrane, C, of the
spinal canal. The brain is continuous with the spinal cord. The
intervertebral foramina of the cervical spine are manifesting serial
order with the cranial foramina. The nerves which pass through the
spinal region of this series of foramina above and below C are
continuous with the nerves which pass through the cranial region. The
anterior boundary, D I, of the cervical spine is continuous with the
anterior boundary, Y F, of the cranial cavity. And this common serial
order of osseous parts--viz., the bodies of vertebrae, serves to
isolate the cranio-spinal compartment from the facial and cervical
passages. Thus the anterior boundary, Y F D I, of the cranio-spinal
canal is also the posterior boundary of the facial and cervical
cavities.
Now as the cranio-spinal chamber is lined by the common dura-matral
membrane, and contains the common mass of nervous structure, thus
inviting us to fix attention upon this structure as a whole, so we find
that the frontal cavity, Z, the nasal cavity, X W, the oral cavity, 4,
5, S, the pharyngeal and oesophageal passages 8 Q, are lined by the
common mucous membrane, and communicate so freely with each other that
they may be in fact considered as forming a common cavity divided only
by partially formed septa, such as the one, U V, which separates to some
extent the nasal fossa from the oral fossa.
As owing to this continuity of structure, visible between the head and
spine, we may infer the liability which the affections of the one region
have to pass into and implicate the other, so likewise by that
continuity apparent between all compartments of the face, fauces,
oesophagus, and larynx, we may estimate how the pathological condition
of the one region will concern the others.
The cranium, owing to its comparatively superficial and undefended
condition, is liable to fracture. When the cranium is fractured, in
consequence of force applied to its anterior or posterior surfaces, A or
B, Plate 20, the fracture will, for the most part, be confined to the
place whereat the force has been applied, provided the point opposite
has not been driven against some resisting body at the same time. Thus
when the point B is struck by a force sufficient to fracture the bone,
while the point A is not opposed to any resisting body, then B alone
will yield to the force applied; and fracture thus occurring at the
point B, will have happened at the place where the applied force is met
by the force, or weight, or inertia of the head itself. But when B is
struck by any ponderous body, while A is at the same moment forced
against a resisting body, then A is also liable to suffer fracture. If
fracture in one place be attended with counter-fracture in another
place, as at the opposite points A and B, then the fracture occurs from
the force impelling, while the counter-fracture happens by the force
resisting.
Now in the various motions which the cranium A A B performs upon the top
of the cervical spine C, motions backwards, forwards, and to either
side, it will follow that, taking C as a fixed point, almost all parts
of the cranial periphery will be brought vertical to C in succession,
and therefore whichever point happens at the moment to stand opposite to
C, and has impelling force applied to it, then C becomes the point of
resistance, and thus counter-fractures at the cranial base occur in the
neighbourhood of C. When force is applied to the cranial vertex, whilst
the body is in the erect posture, the top of the cervical spine, E D C,
becomes the point of resistance. Or if the body fall from a height upon
its cranial vertex, then the propelling force will take effect at the
junction of the spine with the cranial base, whilst the resisting force
will be the ground upon which the vertex strikes. In either case the
cranial base, as well as the vertex, will be liable to fracture.
The anatomical form of the cranium is such as to obviate a frequent
liability to fracture. Its rounded shape diffuses, as is the case with
all rotund forms, the force which happens to strike upon it. The mode in
which the cranium is set upon the cervical spine serves also to diffuse
the pressure at the points where the two opposing forces meet--viz., at
the first cervical vertebra E and the cranial basilar process F. This
fact might be proved upon mechanical principle.
The tegumentary envelope of the head, as well as the dura-matral lining,
serves to damp cranial vibration consequent upon concussion; while the
sutural isolation of the several component bones of the cranium also
prevents, in some degree, the extension of fractures and the vibrations
of concussion. The contents of the head, like the contents of all hollow
forms, receive the vibratory influence of force externally applied. The
brain receives the concussion of the force applied to its osseous
envelope; and when this latter happens to be fractured, the danger to
life is not in proportion to the extent of the fracture here, any more
than elsewhere in the skeleton fabric, but is solely in proportion to
the amount of shock or injury sustained by the nervous centre.
When it is required to trephine any part of the cranial envelope, the
points which should be avoided, as being in the neighbourhood of
important bloodvessels, are the following--the occipital protuberance,
B, within which the "torcular Herophili" is situated, and from this
point passing through the median line of the vertex forwards to Z the
frontal sinus, the trephine should not be applied, as this line marks
the locality of the superior longitudinal sinus. The great lateral sinus
is marked by the superior occipital ridge passing from the point B
outwards to the mastoid process. The central point B of the side of the
head, Plate 21, marks the locality of the root of the meningeal artery
within the cranium, and from this point the vessel branches forwards and
backwards over the interior of the cranium.
The nasal fossae are situated on either side of the median partition
formed by the vomer and cartilaginous nasal septum. Both nasal fossae
are open anteriorly and posteriorly; but laterally they do not, in the
normal state of these parts, communicate. The two posterior nares
answering to the two nasal fossae open into the upper part of the bag of
the pharynx at 8, Plate 20, which marks the opening of the Eustachian
tube.
The structures observable in both the nasal fossae absolutely
correspond, and the foramina which open into each correspond likewise.
All structures situated on either side of the median line are similar.
And the structure which occupies the median line is itself double, or
duality fused into symmetrical unity. The osseous nasal septum is
composed of two laminae laid side by side. The spongy bones, X W, are
attached to the outer wall of the nasal fossa, and are situated one
above the other. These bones are three in number, the uppermost is the
smallest. The outer wall of each naris is grooved by three fossae,
called meatuses, and these are situated between the spongy bones. Each
meatus receives one or more openings of various canals and cavities of
the facial apparatus. The sphenoidal sinus near F opens into the upper
meatus. The frontal, Z, and maxillary sinuses open into the middle
meatus, and the nasal duct opens into the inferior sinus beneath the
anterior inferior angle of the lower spongy bone, W.
In the living body the very vascular fleshy and glandular Schneiderian
membrane which lines all parts of the nasal fossa almost completely
fills this cavity. When polypi or other growths occupy the nasal fossae,
they must gain room at the expense of neighbouring parts. The nasal duct
may have a bent probe introduced into it by passing the instrument along
the outer side of the floor of the nasal fossa as far back as the
anterior inferior angle of the lower spongy bone, W, at which locality
the duct opens. An instrument of sufficient length, when introduced into
the nostrils in the same direction, will, if passed backwards through
the posterior nares, reach the opening of the Eustachian tube, 8.
While the jaws are closed, the tongue, R, Plate 20, occupies the oral
cavity almost completely. When the jaws are opened they form a cavity
between them equal in capacity to the degree at which they are sundered
from each other. The back of the pharynx can be seen when the jaws are
widely opened if the tongue be depressed, as R, Plate 20. The hard
palate, U, which forms the roof of the mouth, is extended further
backwards by the soft palate, V, which hangs as the loose velum of the
throat between the nasal fossae above and the fauces below. Between the
velum palati, V, and the root of the tongue, we may readily discern,
when the jaws are open, two ridges of arching form, 5, 6, on either side
of the fauces. These prominent arches and their fellows are named the
pillars of the fauces. The anterior pillar, 5, is formed by the
submucous palato-glossus muscle; the posterior pillar, 6, is formed by
the palato-pharyngeus muscle. Between these pillars, 5 and 6, is
situated the tonsil, S, beneath the mucous membrane. When the tonsils of
opposite sides become inflamed and suppurate, an incision may be made
into either gland without much chance of wounding the internal carotid
artery; for, in fact, this vessel lies somewhat removed from it behind.
In Plate 21, that point of the superior constrictor of the pharynx,
marked D, indicates the situation of the tonsil gland; and a
considerable interval will be seen to exist between D and the internal
carotid vessel F.
If the head be thrown backwards the nasal and oral cavities will look
almost vertically towards the pharyngeal pouch. When the juggler is
about to "swallow the sword," he throws the head back so as to bring the
mouth and fauces in a straight line with the pharynx and oesophagus. And
when the surgeon passes the probang or other instruments into the
oesophagus, he finds it necessary to give the head of the person on whom
he operates the same inclination backwards. When instruments are being
passed into the oesophagus through the nasal fossa, they are not so
likely to encounter the rima glottidis below the epiglottis, 9, as when
they are being passed into the oesophagus by the mouth. The glottis may
be always avoided by keeping the point of the instrument pressing
against the back of the pharynx during its passage downwards.
When in suspended animation we endeavour to inflate the lungs through
the nose or mouth, we should press the larynx, 10, 11,12, backwards
against the vertebral column, so as to close the oesophageal tube.
DESCRIPTION OF PLATES 20 & 21.
PLATE 20.
A A. The dura-matral falx; A*, its attachment to the tentorium.
B. Torcular Herophili.
C. Dura-mater lining the spinal canal.
D D*. Axis vertebra.
E E*. Atlas vertebra.
F F*. Basilar processes of the sphenoid and occipital bones.
G. Petrous part of the temporal bone.
H. Cerebellar fossa.
I I*. Seventh cervical vertebra.
K K*. First rib surrounding the upper part of the pleural sac.
L L*. Subclavian artery of the right side overlying the pleural sac.
M M*. Right subclavian vein.
N. Right common carotid artery cut at its origin.
O. Trachea.
P. Thyroid body.
Q. Oesophagus.
R. Genio-hyo-glossus muscle.
S. Left tonsil beneath the mucous membrane.
T. Section of the lower maxilla.
U. Section of the upper maxilla.
V. Velum palati in section.
W. Inferior spongy bone.
X. Middle spongy bone.
Y. Crista galli of oethmoid bone.
Z. Frontal sinus.
2. Anterior cartilaginous part of nasal septum.
3. Nasal bone.
4. Last molar tooth of the left side of lower jaw.
5. Anterior pillar of the fauces.
6. Posterior pillar of the fauces.
7. Genio-hyoid muscle.
8. Opening of Eustachian tube.
9. Epiglottis.
10. Hyoid bone.
11. Thyroid bone.
12. Cricoid bone.
13. Thyroid axis.
14. Part of anterior scalenus muscle.
15. Humeral end of the clavicle.
16. Part of posterior scalenus muscle.
[Illustration: Head and neck, in section, from front to back; showing
blood vessels, muscles and other internal organs.]
Plate 20
PLATE 21.
A. Zygoma.
B. Articular glenoid fossa of temporal bone.
C. External pterygoid process lying on the levator and tensor palati
muscles.
D. Superior constrictor of pharynx.
E. Transverse process of the Atlas.
F. Internal carotid artery. Above the point F, is seen the
glosso-pharyngeal nerve; below F, is seen the hypoglossal nerve.
G. Middle constrictor of pharynx.
H. Internal jugular vein.
I. Common carotid cut across.
K. Rectus capitis major muscle.
L. Inferior constrictor of pharynx.
M. Levator anguli scapulae muscle.
N. Posterior scalenus muscle.
O. Anterior scalenus muscle.
P. Brachial plexus of nerves.
Q. Trachea.
R R*. Subclavian artery.
S. End of internal jugular vein.
T. Bracheo-cephalic artery.
U U*. Roots of common carotid arteries.
V. Thyroid body.
W. Thyroid cartilage.
X. Hyoid bone.
Y. Hyo-glossus muscle.
Z. Upper maxillary bone.
2. Inferior maxillary branch of fifth cerebral nerve.
3. Digastric muscle cut.
4. Styloid process.
5. External carotid artery.
6 6. Lingual artery.
7. Roots of cervical plexus of nerves.
8. Thyroid axis; 8*, thyroid artery, between which and Q, the trachea,
is seen the inferior laryngeal nerve.
9. Omo-hyoid muscle cut.
10. Sternal end of clavicle.
11. Upper rings of trachea, which may with most safety be divided in
tracheotomy.
12. Cricoid cartilage.
13. Crico-thyroid interval where laryngotomy is performed.
14. Genio-hyoid muscle.
15. Section of lower maxilla.
16. Parotid duct.
17. Lingual attachment of styloglossus muscle, with part of the
gustatory nerve seen above it.
[Illustration: Head and neck, showing blood vessels, muscles and other
internal organs.]
Plate 21
COMMENTARY ON PLATE 22.
THE RELATIVE POSITION OF THE SUPERFICIAL ORGANS OF THE THORAX AND ABDOMEN.
In the osseous skeleton, the thorax and abdomen constitute a common
compartment. We cannot, while we contemplate this skeleton, isolate the
one region from the other by fact or fancy. The only difference which I
can discover between the regions called thorax and abdomen, in the
osseous skeleton, (considering this body morphologically,) results,
simply, from the circumstance that the ribs, which enclose thoracic
space, have no osseous counterparts in the abdomen enclosing abdominal
space, and this difference is merely histological. In man and the
mammalia the costal arches hold relation with the pulmonary organs, and
these costae fail at that region where the ventral organs are located.
In birds, and many reptiles, the costal arches enclose the common
thoracico-abdominal region, as if it were a common pulmonary region. In
fishes the costal arches enclose the thoracico-abdominal region, just as
if it were a common abdominal region. I merely mention these general
facts to show that costal enclosure does not actually serve to isolate
the thorax from the abdomen in the lower classes of animals; and on
turning to the human form, I find that this line of separation between
the two compartments is so very indefinite, that, as pathologists, we
are very liable to err in our diagnosis between the diseased and the
healthy organs of either region, as they lie in relation with the
moveable diaphragm or septum in the living body. The contents of the
whole trunk of the body from the top of the sternum to the perineum are
influenced by the respiratory motions; and it is most true that the
diaphragmatic line, H F H*, is alternately occupied by those organs
situated immediately above and below it during the performance of these
motions, even in health.
The organs of the thoracic region hold a certain relation to each other
and to the thoracic walls. The organs of the abdomen hold likewise a
certain relation to each other and to the abdominal parietes. The organs
of both the thorax and the abdomen have a certain relation to each
other, as they lie above and below the diaphragm. In dead nature these
relations are fixed and readily ascertainable, but in living, moving
nature, the organs influence this relative position, not only of each
other, but also of that which they bear to the cavities in which they
are contained. This change of place among the organs occurs in the
normal or healthy state of the living body, and, doubtless, raises some
difficulty in the way of our ascertaining, with mathematical precision,
the actual state of the parts which we question, by the physical signs
of percussion and auscultation. In disease this change of place among
these organs is increased, and the difficulty of making a correct
diagnosis is increased also in the same ratio. For when an emphysematous
lung shall fully occupy the right thoracic side from B to L, then G, the
liver, will protrude considerably into the abdomen beneath the right
asternal ribs, and yet will not be therefore proof positive that the
liver is diseased and abnormally enlarged. Whereas, on the other hand,
when G, the liver, is actually diseased, it may occupy a situation in
the right side as high as the fifth or sixth ribs, pushing the right
lung upwards as high as that level; and, therefore, while percussion
elicits a dull sound over this place thus occupied, such sound will not
be owing to a hepatized lung, but to the absence of the lung caused by
the presence of the liver.
In the healthy adult male body, Plate 22, the two lungs, D D*, whilst in
their ordinary expanded state, may be said to range over all that region
of the trunk of the body which is marked by the sternal and asternal
ribs. The heart, E, occupies the thoracic centre, and part of the left
thoracic side. The heart is almost completely enveloped in the two
lungs. The only portion of the heart and pericardium, which appears
uncovered by the lung on opening the thorax, is the base of the right
ventricle, E, situated immediately behind the lower end of the sternum,
where this bone is joined by the cartilages of the sixth and seventh
ribs. The lungs range perpendicularly from points an inch above B, the
first rib, downwards to L, the tenth rib, and obliquely downwards and
backwards to the vertebral ends of the last ribs. This space varies in
capacity, according to the degree in which the lungs are expanded within
it. The increase in thoracic space is attained, laterally, by the
expansion of the ribs, C I; and vertically, by the descent of the
diaphragm, H, which forces downwards the mass of abdominal viscera. The
contraction of thoracic space is caused by the approximation of all the
ribs on each side to each other; and by the ascent of the diaphragm. The
expansion of the lungs around the heart would compress this organ, were
it not that the costal sides yield laterally while the diaphragm itself
descends. The heart follows the ascent and descent of the diaphragm,
both in ordinary and forced respiration.
But however much the lungs vary in capacity, or the heart as to position
in the respiratory motions, still the lungs are always closely applied
to the thoracic walls. Between the pleura costalis and pulmonalis there
occurs no interval in health. The thoracic parietes expand and contract
to a certain degree; and to that same degree, and no further, do the
lungs within the thorax expand and contract. By no effort of expiration
can the animal expel all the air completely from its lungs, since by no
effort of its own, can it contract thoracic space beyond the natural
limit. On the other hand, the utmost degree of expansion of which the
lungs are capable, exactly equals that degree in which the thoracic
walls are dilatable by the muscular effort; and, therefore, between the
extremes of inspiration and expiration, the lungs still hold closely
applied to the costal parietes. The air within the lungs is separated
from the air external to the thorax, by the thoracic parietes. The air
within and external to the lungs communicate at the open glottis. When
the glottis closes and cuts off the communication, the respiratory act
ceases--the lungs become immovable, and the thoracic walls are (so far
as the motions of respiration are concerned) rendered immovable also.
The muscles of respiration cannot, therefore, produce a vacuum between
the pulmonic and costal pleura, either while the external air has or has
not access to the lungs. Upon this fact the mechanism of respiration
mainly depends; and we may see a still further proof of this in the
circumstance that, when the thoracic parietes are pierced, so as to let
the external air into the cavity of the pleura, the lung collapses and
the thoracic side ceases to exert an expansile influence over the lung.
When in cases of fracture of the rib the lung is wounded, and the air of
the lung enters the pleura, the same effect is produced as when the
external air was admitted through an opening in the side.
When serous or purulent effusion takes place within the cavity of the
pleura, the capacity of the lung becomes lessened according to the
quantity of the effusion. It is more reasonable to expect that the soft
tissue of the lung should yield to the quantity of fluid within the
pleural cavity, than that the rigid costal walls should give way
outwardly; and, therefore, it seldom happens that the practitioner can
discover by the eye any strongly-marked difference between the thoracic
walls externally, even when a considerable quantity of either serum,
pus, or air, occupies the pleural sacs.
In the healthy state of the thoracic organs, a sound characteristic of
the presence of the lung adjacent to the walls of the thorax may be
elicited by percussion, or heard during the respiratory act through the
stethoscope, over all that costal space ranging anteriorly between B,
the first rib, and I K, the eight and ninth ribs. The respiratory murmur
can be heard below the level of these ribs posteriorly, for the lung
descends behind the arching diaphragm as far as the eleventh rib.
When fluid is effused into the pleural cavity, the ribs are not moved by
the intercostal muscles opposite the place occupied by the fluid, for
this has separated the lung from the ribs. The fluid has compressed the
lung; and in the same ratio as the lung is prevented from expanding, the
ribs become less moveable. The presence of fluid in the pleural sac is
discoverable by dulness on percussion, and, as might be expected, by the
absence of the respiratory murmur at that locality which the fluid
occupies. Fluid, when effused into the pleural sac, will of course
gravitate; and its position will vary according to the position of the
patient. The sitting or standing posture will therefore suit best for
the examination of the thorax in reference to the presence of fluid.
Though the lungs are closely applied to the costal sides at all times in
the healthy state of these organs, still they slide freely within the
thorax during the respiratory motions--forwards and backwards--over the
serous pericardium, E, and upwards and downwards along the pleura
costalis. The length of the adhesions which supervene upon pleuritis
gives evidence of the extent of these motions. When the lung becomes in
part solidified and impervious to the inspired air, the motions of the
thoracic parietes opposite to the part are impeded. Between a solidified
lung and one which happens to be compressed by effused fluid it requires
no small experience to distinguish a difference, either by percussion or
the use of the stethoscope. It is great experience alone that can
diagnose hydro-pericardium from hypertrophy of the substance of the
heart by either of these means.
The thoracic viscera gravitate according to the position of the body.
The heart in its pericardial envelope sways to either side of the
sternal median line according as the body lies on this or that side. The
two lungs must, therefore, be alternately affected as to their capacity
according as the heart occupies space on either side of the thorax. In
expiration, the heart, E, is more uncovered by the shelving edges of the
lungs than in inspiration. In pneumothorax of either of the pleural sacs
the air compresses the lung, pushes the heart from its normal position,
and the space which the air occupies in the pleura yields a clear hollow
sound on percussion, whilst, by the ear or stethoscope applied to a
corresponding part of the thoracic walls, we discover the absence of the
respiratory murmur.
The transverse diameter of the thoracic cavity varies at different
levels from above downwards. The diameter which the two first ribs, B
B*, measure, is the least. That which is measured by the two eighth
ribs, I I*, is the greatest. The perpendicular depth of the thorax,
measured anteriorly, ranges from A, the top of the sternum, to F, the
xyphoid cartilage. Posteriorly, the perpendicular range of the thoracic
cavity measures from the spinous process of the seventh cervical
vertebra above, to the last dorsal spinous process below. In full,
deep-drawn inspiration in the healthy adult, the ear applied to the
thoracic walls discovers the respiratory murmur over all the space
included within the above mentioned bounds. After extreme expiration, if
the thoracic walls be percussed, this capacity will be found much
diminished; and the extreme limits of the thoracic space, which during
full inspiration yielded a clear sound, indicative of the presence of
the lung, will now, on percussion, manifest a dull sound, in consequence
of the absence of the lung, which has receded from the place previously
occupied.
Owing to the conical form of the thoracic space, the apex of which is
measured by the first ribs, B B*, and the basis by I I*, it will be seen
that if percussion be made directly from before, backwards, over the
pectoral masses, R R*, the pulmonic resonance will not be elicited. When
we raise the arms from the side and percuss the thorax between the folds
of the axillae, where the serratus magnus muscle alone intervenes
between the ribs and the skin, the pulmonic sound will answer clearly.
At the hypochondriac angles formed between the points F, L, N, on either
side the lungs are absent both in inspiration and expiration.
Percussion, when made over the surface of the angle of the right side,
discovers the presence of the liver, G G*. When made over the median
line, and on either side of it above the umbilicus, N, we ascertain the
presence of the stomach, M M*. In the left hypochondriac angle, the
stomach may also be found to occupy this place wholly.
Beneath the umbilicus, N, and on either side of it as far outwards as
the lower asternal ribs, K L, thus ranging the abdominal parietes
transversely, percussion discovers the transverse colon, O, P, O*. The
small intestines, S S*, covered by the omentum, P*, occupy the
hypogastric and iliac regions.
The organs situated within the thorax give evidence that they are
developed in accordance to the law of symmetry. The lungs form a pair,
one placed on either side of the median line. The heart is a double
organ, formed of the right and left heart. The right lung differs from
the left, inasmuch as we find the former divided into three lobes, while
the latter has only two. That place which the heart now occupies in the
left thoracic side is the place where the third or middle lobe of the
left lung is wanting. In the abdomen we find that most of its organs are
single. The liver, stomach, spleen, colon, and small intestine form a
series of single organs: each of these may be cleft symmetrically. The
kidneys are a pair.
The extent to which the ribs are bared in the figure Plate 22, marks
exactly the form and transverse capacity of the thoracic walls. The
diaphragm, H H*, has had a portion of its forepart cut off, to show how
it separates the thin edges of both lungs above from the liver, G, and
the stomach, M, below. These latter organs, although occupying abdominal
space, rise to a considerable height behind K L, the asternal ribs, a
fact which should be borne in mind when percussing the walls of the
thorax and abdomen at this region.
DESCRIPTION OF PLATE 22.
A. Upper bone of the sternum.
B B*. Two first ribs.
C C*. Second pair of ribs.
D D*. Right and left lungs.
E. Pericardium, enveloping the heart--the right ventricle.
F. Lower end of the sternum.
G G*. Lobes of the liver.
H H*. Right and left halves of the diaphragm in section. The right half
separating the right lung from the liver; the left half separating
the left lung from the broad cardiac end of the stomach.
I I*. Eighth pair of ribs.
K K*. Ninth pair of ribs.
L L*. Tenth pair of ribs.
M M*. The stomach; M, its cardiac bulge; M*, its pyloric extremity.
N. The umbilicus.
OO*. The transverse colon.
P P*. The omentum, covering the transverse colon and small intestines.
Q. The gall bladder.
R R*. The right and left pectoral prominences.
S S*. Small intestines.
[Illustration: Chest and abdomen, showing bones, blood vessels, muscles
and other internal organs.]
Plate 22
COMMENTARY ON PLATE 23.
THE RELATIVE POSITION OF THE DEEPER ORGANS
OF THE THORAX AND THOSE OF THE ABDOMEN.
The size or capacity of the thorax in relation to that of the abdomen
varies in the individual at different periods of life. At an early age,
the thorax, compared to the abdomen, is less in proportion than it is at
adult age. The digestive organs in early age preponderate considerably
over the respiratory organs; whereas, on the contrary, in the healthy
and well-formed adult, the thoracic cavity and organs of respiration
manifest a greater relative proportion to the ventral cavity and organs.
At the adult age, when sexual peculiarities have become fully marked,
the thoracic organs of the male body predominate over those of the
abdomen, whilst in the female form the ventral organs take precedence as
to development and proportions. This diversity in the relative capacity
of the thorax and abdomen at different stages of development, and also
in persons of different sexes, stamps each individual with
characteristic traits of physical conformation; and it is required that
we should take into our consideration this normal diversity of
character, while conducting our examinations of individuals in reference
to the existence of disease.
The heart varies in some measure, not only as to size and weight, but
also as to position, even in healthy individuals of the same age and
sex. The level at which the heart is in general found to be situated in
the thorax is that represented in PLATE 23, where the apex points to the
sixth intercostal space on the left side above K, while the arch of the
aorta rises to a level with C, the second costal cartilage. In some
instances, the heart may be found to occupy a much lower position in the
thorax than the one above mentioned, or even a much higher level. The
impulse of the right ventricle, F, has been noticed occasionally as
corresponding to a point somewhat above the middle of the sternum and
the intercostal space between the fourth and fifth left costal
cartilages; while in other instances its beating was observable as low
down as an inch or more below the xiphoid cartilage, and these
variations have existed in a state of health.
Percussion over the region of the heart yields a dull flat sound. The
sound is dullest opposite the right ventricle, F; whilst above and to
either side of this point, where the heart is overlapped by the anterior
shelving edges of both lungs, the sound is modified in consequence of
the lung's resonant qualities. The heart-sounds, as heard through the
stethoscope, in valvular disease, will, of course, be more distinctly
ascertained at the locality of F, the right ventricle, which is
immediately substernal. While the body lies supine, the heart recedes
from the forepart of the chest; and the lungs during inspiration
expanding around the heart will render its sounds less distinct. In the
erect posture, the heart inclines forwards and approaches the anterior
wall of the thorax. When the heart is hypertrophied, the lungs do not
overlap it to the same extent as when it is of its ordinary size. In the
latter state, the elastic cushion of the lung muffles the heart's
impulse. In the former state, the lung is pushed aside by the overgrown
heart, the strong muscular walls of which strike forcibly against the
ribs and sternum.
The thorax is separated from the abdomen by the moveable diaphragm. The
heart, F E, lies upon the diaphragm, L L*. The liver, M, lies
immediately beneath the right side of this muscular septum, L*, while
the bulging cardiac end of the stomach, O, is in close contact with it
on the left side, L. As these three organs are attached to the
diaphragm--the heart by its pericardium, the stomach by the tube of the
oesophagus, and the liver by its suspensory ligaments--it must happen
that the diaphragm while descending and ascending in the motions of
inspiration and expiration will communicate the same alternate motions
to the organs which are connected with it.
In ordinary respiration the capacity of the thorax is chiefly affected
by the motions of the diaphragm; and the relative position which this
septum holds with regard to the thoracic and abdominal chambers will
cause its motions of ascent and descent to influence the capacity of
both chambers at the same time. When the lungs expand, they follow the
descent of the diaphragm, which forces the abdominal contents downwards,
and thus what the thorax gains in space the abdomen loses. When the
lungs contract, the diaphragm ascends, and by this act the abdomen gains
that space which the thorax loses. But the organs of the thoracic cavity
perform a different office in the economy from those of the abdomen. The
air which fills the lungs is soon again expired, whilst the ingesta of
the abdominal viscera are for a longer period retained; and as the
space, which by every inspiration the thorax gains from the abdomen,
would cause inconvenient pressure on the distended organs of this latter
cavity, so we find that to obviate this inconvenience, nature has
constructed the anterior parietes of the abdomen of yielding material.
The muscular parietes of the abdomen relax during every inspiration, and
thus this cavity gains that space which it loses by the encroachment of
the dilating lungs.
The mechanical principle upon which the abdominal chamber is
constructed, enables it to adjust its capacity to such exigence or
pressing necessity as its own visceral organs impose on it, from time to
time; and the relation which the abdominal cavity bears to the thoracic
chamber, enables it also to be compensatory to this latter. When the
inspiratory thorax gains space from the abdomen, or when space is
demanded for the increasing bulk of the alimentary canal, or for the
enlarging pregnant uterus; or when, in consequence of disease, such as
dropsical accumulation, more room is wanted, then the abdominal chamber
supplies the demand by the anterior bulge or swell of its expansile
muscular parietes.
The position of the heart itself is affected by the expansion of the
lungs on either side of it. As the expanding lungs force the diaphragm
downwards, the heart follows it, and all the abdominal viscera yield
place to the descending thoracic contents. In strong muscular efforts
the diaphragm plays an important part, for, previously to making forced
efforts, the lungs are distended with air, so as to swell and render
fixed the thoracic walls into which so many powerful muscles of the
shoulders, the neck, back, and abdomen, are inserted; at the same time
the muscular diaphragm L L*, becomes tense and unbent from its arched
form, thereby contracting abdominal space, which now has no compensation
for this loss of space, since the abdominal parietes are also rendered
firm and unyielding. It is at this crisis of muscular effort that the
abdominal viscera become impacted together; and, acting by their own
elasticity against the muscular force, make an exit for themselves
through the weakest parts of the abdominal walls, and thus herniae of
various kinds are produced. The most common situations of abdominal
herniae are at the inguinal regions, towards which the intestines, T T,
naturally gravitate; and at these situations the abdominal parietes are
weak and membranous.
The contents of a hernial protrusion through the abdominal parietes,
correspond in general with those divisions of the intestinal tube, which
naturally lie adjacent to the part where the rupture has taken place. In
the umbilical hernia it is either the transverse colon S*, or some part
of the small intestine occupying the median line, or both together, with
some folds of the omentum, which will be found to form the contents of
this swelling. When the diaphragm itself sustains a rupture in its left
half, the upper portion of the descending colon, S, protrudes through
the opening. A diaphragmatic hernia has not, so far as I am aware, been
seen to occur in the right side; and this exemption from rupture of the
right half of the diaphragm may be accounted for anatomically, by the
fact that the liver, M, defends the diaphragm at this situation. The
liver occupies the whole depth of the right hypochondrium; and
intervenes between the diaphragm L*, and the right extremity of the
transverse colon, S**.
The contents of a right inguinal hernia consist of the small intestine,
T. The contents of the right crural hernia are formed by either the
small intestine, T, or the intestinum caecum, S***. I have seen a few
cases in which the caecum formed the right crural hernia. Examples are
recorded in which the intestine caecum formed the contents of a right
inguinal hernia. The left inguinal and crural herniae contain most
generally the small intestine, T, of the left side.
The right lung, I*, is shorter than the left; for the liver, M, raises
the diaphragm, L, to a higher level within the thorax, on the right
side, than it does on the left. When the liver happens to be diseased
and enlarged, it encroaches still more on thoracic space; but,
doubtless, judging from the anatomical connexions of the liver, we may
conclude that when it becomes increased in volume it will accommodate
itself as much at the expense of abdominal space. The liver, in its
healthy state and normal proportions, protrudes for an inch (more or
less) below the margins of the right asternal ribs. The upper or convex
surface of the liver rises beneath the diaphragm to a level
corresponding with the seventh or sixth rib, but this position will vary
according to the descent and ascent of the diaphragm in the respiratory
movements. The ligaments by which the liver is suspended do not prevent
its full obedience to these motions.
The left lung, I, descends to a lower level than the right; and the left
diaphragm upon which it rests is itself supported by the cardiac end of
the stomach. When the stomach is distended, it does not even then
materially obstruct the expansion of the left lung, or the descent of
the left diaphragm, for the abdominal walls relax and allow of the
increasing volume of the stomach to accommodate itself. The spleen, R,
is occasionally subject to an extraordinary increase of bulk; and this
organ, like the enlarged liver and the distended stomach, will, to some
extent, obstruct the movements of the diaphragm in the act of
respiration, but owing to its free attachments it admits of a change of
place. The abdominal viscera, one and all, admit of a change of place;
the peculiar forms of those mesenteric bonds by which they are
suspended, allow them to glide freely over each other; and this
circumstance, together with the yielding nature of the abdominal
parietes, allows the thoracic organs to have full and easy play in the
respiratory movements performed by agency of the diaphragm.
The muscles of respiration perform with ease so long as the air has
access to the lungs through the normal passage, viz., the trachea. While
the principle of the thoracic pneumatic apparatus remains underanged,
the motor powers perform their functions capably. The physical or
pneumatic power acts in obedience to the vital or muscular power, while
both stand in equilibrium; but the ascendancy of the one over the other
deranges the whole thoracic machine. When the glottis closes by muscular
spasm and excludes the external air, the respiratory muscles cease to
exert a motor power upon the pulmonary cavity; their united efforts
cannot cause a vacuum in thoracic space in opposition to the pressure of
the external air. When, in addition to the natural opening of the
glottis, a false opening is made in the side at the point K, the air
within the lung at I, and external to it in the now open pleural cavity,
will stand in equilibrio; the lung will collapse as having no muscular
power by which to dilate itself, and the thoracic dilator muscles will
cease to affect the capacity of the lung, so long as by their action in
expanding the thoracic walls, the air gains access through the side to
the pleural sac external to the lung.
Whether the air be admitted into the pleural sac, by an opening made in
the side from without, or by an opening in the lung itself, the
mechanical principle of the respiratory apparatus will be equally
deranged. Pneumo-thorax will be the result of either lesion; and by the
accumulation of air in the pleura the lung will suffer pressure. This
pressure will be permanent so long as the air has no egress from the
cavity of the pleura.
The permanent distention of the thoracic cavity, caused by the
accumulation of air in the pleural sac, or by the diffusion of air
through the interlobular cellular tissue consequent on a wound of the
lung itself, will equally obstruct the breathing; and though the
situation of the accumulated air is in fact anatomically different in
both cases, yet the effect produced is similar. Interlobular pressure
and interpleural pressure result in the same thing, viz., the permanent
retention of the air external to the pulmonary cells, which, in the
former case, are collapsed individually; and, in the latter case, in the
mass. Though the emphysematous lung is distended to a size equal to the
healthy lung in deep inspiration, yet we know that emphysematous
distention, being produced by extrabronchial air accumulation, is, in
fact, obstructive to the respiratory act. The emphysematous lung will,
in the same manner as the distended pleural sac, depress the diaphragm
and render the thoracic muscles inoperative. The foregoing observations
have been made in reference to the effect of wounds of the thorax, the
proper treatment of which will be obviously suggested by our knowledge
of the state of the contained organs which have suffered lesion.
DESCRIPTION OF PLATE 23.
A. Upper end of the sternum.
B B.* First pair of ribs.
C C.* Second pair of ribs.
D. Aorta, with left vagus and phrenic nerves crossing its transverse
arch.
E. Root of pulmonary artery.
F. Right ventricle.
G. Right auricle.
H. Vena cava superior, with right phrenic nerve on its outer border.
I I*. Right and left lungs collapsed, and turned outwards, to show the
heart's outline.
K K*. Seventh pair of ribs.
L L*. The diaphragm in section.
M. The liver in section.
N. The gall bladder with its duct joining the hepatic duct to form the
common bile duct. The hepatic artery is seen superficial to the common
duct; the vena portae is seen beneath it. The patent orifices of the
hepatic veins are seen on the cut surface of the liver.
O. The stomach.
P. The coeliac axis dividing into the coronary, splenic and hepatic
arteries.
Q. Inferior vena cava.
R. The spleen.
S S* S**. The transverse colon, between which and the lower border of
the stomach is seen the gastro-epiploic artery, formed by
the splenic and hepatic arteries.
S***. Ascending colon in the right iliac region.
T. Convolutions of the small intestines distended with air.
[Illustration: Chest and abdomen, showing bones, blood vessels, muscles
and other internal organs.]
Plate 23
COMMENTARY ON PLATE 24.
THE RELATIONS OF THE PRINCIPAL BLOODVESSELS
TO THE VISCERA OF THE THORACICO-ABDOMINAL CAVITY.
The median line of the body is occupied by the centres of the four great
systems of organs which serve in the processes of circulation,
respiration, innervation, and nutrition. These organs being fashioned in
accordance with the law of symmetry, we find them arranged in close
connexion with the vertebrate centre of the osseous fabric, which is
itself symmetrical. In this symmetrical arrangement of the main organs
of the trunk of the body, a mechanical principle is prominently
apparent; for as the centre is the least moveable and most protected
region of the form, so have these vitally important structures the full
benefit of this situation. The aortal trunk, G, of the arterial system
is disposed along the median line, as well for its own safety as for the
fitting distribution of those branches which spring symmetrically from
either side of it to supply the lateral regions of the body.
The visceral system of bloodvessels is moulded upon the organs which
they supply. As the thoracic viscera differ in form and functional
character from those of the abdomen, so we find that the arterial
branches which are supplied by the aorta to each set, differ likewise in
some degree. In the accompanying figure, which represents the thoracic
and abdominal visceral branches of the aorta taken in their entirety,
this difference in their arrangement may be readily recognised. In the
thorax, compared with the abdomen, we find that not only do the aortic
branches differ in form according to the variety of those organs
contained in either region, but that they differ numerically according
to the number of organs situated in each. The main vessel itself,
h
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