General Anatomy, Applied to Physiology and Medicine, Vol. 2 (of 3)

Part 1

GENERAL ANATOMY,

APPLIED TO

PHYSIOLOGY AND MEDICINE;

BY XAVIER BICHAT,

PHYSICIAN OF THE GREAT HOSPITAL OF HUMANITY AT PARIS, AND PROFESSOR OF ANATOMY AND PHYSIOLOGY.

Translated from the French.

BY GEORGE HAYWARD, M.D.

FELLOW OF THE AMERICAN ACADEMY OF ARTS AND SCIENCES, AND OF THE MASSACHUSETTS MEDICAL SOCIETY.

IN THREE VOLUMES.

VOLUME II.

BOSTON: PUBLISHED BY RICHARDSON AND LORD.

J. H. A. FROST, PRINTER. 1822.

DISTRICT OF MASSACHUSETTS, to wit:

DISTRICT CLERK'S OFFICE.

BE IT REMEMBERED, that on the seventeenth day of April, A.D. 1822, in the forty-sixth year of the Independence of the United States of America, Richardson & Lord, of the said District, have deposited in this office the title of a book, the right whereof they claim as proprietors, in the words following, to wit:

"General Anatomy, applied to Physiology and Medicine; by Xavier Bichat, Physician of the Great Hospital of Humanity at Paris, and Professor of Anatomy and Physiology. Translated from the French, by George Hayward, M. D. Fellow of the American Academy of Arts and Sciences, and of the Massachusetts Medical Society. In three Volumes. Volume II."

In conformity to the Act of the Congress of the United States, entitled, "An Act for the Encouragement of Learning, by securing the Copies of Maps, Charts and Books, to the Authors and Proprietors of such Copies, during the times therein mentioned:" and also to an Act entitled, "An Act supplementary to an Act, entitled, An Act for the encouragement of Learning, by securing the Copies of Maps, Charts and Books, to the Authors and Proprietors of such Copies during the times therein mentioned; and extending the Benefits thereof to the Arts of Designing, Engraving and Etching Historical and other Prints."

JOHN W. DAVIS, Clerk of the District of Massachusetts.

CAPILLARY SYSTEMS.

The two great vascular systems, with red and black blood arise and terminate, as we have said, in the capillaries, which form in the lungs, as in all the other parts the limits that separate them, and in which they are changed from one to the other. There are then evidently two capillary systems distinct from each other, and which are even opposite. One, generally spread throughout the body, is the seat of the change of red blood into black. The other, confined wholly to the lungs, exhibits an opposite phenomenon; it is in its divisions that the black blood becomes red.

As the capillaries, which serve for the origin and termination of the black abdominal blood, are intermixed on both sides with those of the general capillary system, since in the abdomen they are continued with the arteries and in the liver give origin to the veins, I shall omit them in these remarks, and attend only to the general and pulmonary capillary systems.

These two capillary systems, the first especially, deserve the more particular consideration, 1st, because the circulation is governed in it by laws wholly different from those of the other parts; 2d, because most of the important functions of life take place there, as secretions, nutrition, exhalations, &c.; 3d, because their small tubes are affected on many occasions by diseases, as they are the seat of inflammations, metastases, &c.; 4th, because animal heat is especially produced in these tubes, &c.

The lowest species of animals have in reality only a capillary circulation. Their fluids do not move in great masses, in canals which carry them to all parts of the body, and afterwards bring them back again. There is only an insensible oscillation of these fluids, in tubes of the greatest delicacy and number. This kind of circulation is one of the points of contact, or rather of transition from animals to vegetables, which, destitute of the circulation with a sensible motion, have evidently like the zoophytes, that of an insensible motion and of the capillary vessels.

I shall first examine the general capillary system, and afterwards the pulmonary.

ARTICLE FIRST.

OF THE GENERAL CAPILLARY SYSTEM.

This system exists in all the organs; all are in fact composed of an infinity of capillaries, which cross, unite, separate and unite again, by communicating in a thousand ways with each other. The vessels of any considerable size, those among the arteries, in which the blood circulates by the influence of the heart, and those among the veins, which correspond to the first, have really no connexion with the structure of the organs; they wind along their interstices; and are lodged in the cellular texture that separates their lobes; but the capillaries alone essentially make part of these organs, they are so combined with them; that they truly enter into the composition of their texture. It is in this view, that we may with truth consider the animal body as an assemblage of vessels.

From this first view, it is evident that the extent of the general capillary system is immense, that it embraces all the smallest divisions of our bodies, so that we can hardly conceive of any organic particles united without capillaries. It follows hence, that this system is not only an intermediate one between the arteries and the veins. It is from it, that all the exhalants, all the excretories, &c. go. It furnishes all the vessels that carry nutritive matter to our organs; we ought to describe it then as existing in parts where arteries do not penetrate, as well as in those where they do.

Part 2

I. General Division of the Capillaries.

Since this system is not destined merely to unite the arteries to the veins, and change the black blood to red, it is evident that other fluids besides the blood, must circulate in them; this is in fact what observation proves. There are many parts in the animal economy, in which white fluids alone circulate. We know the hypothetical opinions of Boerhaave upon the white arteries, the decreasing vessels, &c. We shall find these opinions in all books; I shall only say here what accurate observation shows us. That there is in the general capillary system, parts in which the blood especially moves, others pervaded only by white, or greyish fluids, &c. is a thing of inspection, and has no need of proofs. But what is the proportion of these fluids in the different organs? it is this that must be examined; now there are parts where the blood predominates almost exclusively in the capillary system, others where it exists in part, and in which there is a portion of different fluids, others in fine in which these fluids alone are found.

Of the Organs in which the Capillaries contain only Blood.

It appears that in the muscular system, in the spleen, in certain parts of the mucous surfaces, as in the pituitary membrane, &c. the blood so predominates in the capillary tubes, that almost every other fluid is unknown in them; thus fine injections demonstrate few other vessels; the arteries and the veins are seen there in great abundance. The blood, or its colouring matter, is in them, as I shall say, in two different states; in one, it stagnates and serves then to colour the organ; in the other, it circulates and contributes to its nutrition, its excitement, &c.

Of the Organs in which the Capillaries contain Blood and Fluids differing from it.

These organs are the most numerous in the animal economy. The bones, the cellular texture, the serous membranes, a part of the fibrous system, the skin, the vascular parietes, the glands, &c. &c. exhibit this arrangement in a very remarkable manner.

To give an idea of the capillary system in this kind of organs, let us take one in which it is easy to examine it, the serous membranes, for example. When we lay them bare in a living animal, their transparency permits us to see in an evident manner that they contain but very little blood in their capillary system; there are many branches under them, but they appear to be only contiguous; raise, for example, in a small living guinea-pig the peritoneal coat of the stomach; the red arteries, which at first view appeared to be in this coat, remain untouched. These membranes, certainly owe their white or greyish colour to the small quantity of blood they receive from their small vessels, to which the next trunks give rise. After having thus exposed a serous membrane, in order to see the quantity of blood that is found in it in a natural state, irritate it with any stimulant; at the end of some time, it will be covered by an infinity of reddish streaks, which will be so numerous, that they will change its whiteness into the red colour of the mucous surfaces.

Force fine injections into a dead body, they will so fill the capillary system of the serous surfaces, of those of the peritoneum, for example, that those surfaces will be wholly black, and appear formed only by a net-work of vessels, whilst very few are apparent in the living body, because it is not the blood that fills them. When we cannot open animals to convince us of this, surgical operations, in which the intestines are laid bare, the peritoneum being untouched, wounds of the abdomen, the cesarian operation, &c. will prove incontestably that in the natural state, the blood fills ten and even twenty times less of the vessels, upon the serous surfaces, than injections show us in their texture.

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