Chapter 1

The Project Gutenberg eBook of Surgical Anatomy This eBook is for the use of anyone anywhere in the United States and most other parts of the world at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at www.gutenberg.org. If you are not located in the United States, you will have to check the laws of the country where you are located before using this eBook. Title: Surgical Anatomy Author: Joseph Maclise Release date: January 28, 2008 [eBook #24440] Most recently updated: October 22, 2023 Language: English Other information and formats: www.gutenberg.org/ebooks/24440 Credits: Produced by Don Kostuch *** START OF THE PROJECT GUTENBERG EBOOK SURGICAL ANATOMY *** [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. Each image is inserted immediately following its description. Some of the plates did not fit on the scanner and were captured as two separate images. The merged images show some artifacts of the merge process due to slightly different lighting of the page. The contrast and gamma values have been adjusted to restore the images. 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. 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.