CHAP. VI. Prout in favour of the German results.(o) It has been suggested that SECT. III. the use of the pancreatic juice may be to animalize the unazotised parDIGESTION. ticles of vegetable food;(p) and it has been also observed, that the juice Diseases of tempers the acrid bile, (q) and that the bile is diluted by the pancreatic juice.(r) But the supposed use of the pancreas and spleen will be presently more particularly considered.(s) It has been conjectured by Haller, though it is said erroneously, that the secretion and pouring of this pancreatic juice from the pancreas into the duodenum is equal to eight pounds in the twenty-four hours.(1) Diseases of the pancreas occur but rarely;(u) but it may be affected pancreas. by turgescence, or by chronic induration or enlargement, sometimes accompanied with calculous concretions.(x) The spleen. The spleen is a soft spongy and exceedingly vascular organ. Its colour is deep red, with a tinge of blue, particularly round its margin. Its form is somewhat oval, being smooth and convex on the exterior, where it is in apposition with the diaphragm, and irregularly concave on the opposite side, which is divided into two parts, but unequally, by a transverse slit, for the transmission of its vessels. The spleen has a peritoneal investment prolonged to it from the stomach, by which, as well as by vessels, it is connected to the stomach; but it has also a smooth and fibrous tunic proper to itself. The splenic artery is of considerable size. The vein terminates in the vena portæ, and its nerves are derived from the solar plexus.(y) The spleen secretes no peculiar fluid, its blood is of a dark livid colour, and coagulates with difficulty. It is even destitute of an excreting duct, and in some instances has been extirpated without injury to the general health.(z) The spleen is situate in the left hypochondriac region between the diaphragm and the stomach, and beneath the cartilages of the false ribs.(a) With respect to the use or function of the spleen, it has been observed that it is as yet but little known, but that it may be affirmed to be subservient to digestion.(b) It has been observed, that upon the whole it should seem that the stomach, duodenum, liver, pancreas, and spleen, are united in function;(c) and that the spleen is an organ subservient to the stomach; that it is a provision for giving the vessels of the stomach an occasional power and greater activity, enabling them to pour out a quantity of fluid proportioned to the necessity of the digestion; (d) and that we may conclude that it is not the means of retarding the blood in its circulation, but of giving force to it; (e) and that the probability is, that the venous blood of the spleen is useful to the function of the liver, either by supplying venous blood in proportion to the wants of the liver, or in that venous blood carried to the liver there may be some peculiar change wrought by the spleen, and fitting it for the secretion of bile.(f) Some have suggested that the spleen is a mere diverticulum for the blood during digestion. Others, that the specific function of the spleen is to secrete from the blood a reddish fluid that has the property of coagulating, and (z) 1 Good, 26; 2 Dungl. Phy. 247. (a) 2 Horn. Anat. 56; 3 Bell, 349, 350; 3 Paris & Fonb. 66. (b) 3 Bell, 238, 349, 352; 1 Good, 26; 2 Good, 371; 2 Bost. 397; and see fully 2 Dungl. Phy. 245 to 250. (c) 3 Bell, 238, 354. (e) Id. 238, 355. Id. 356, 357; 1 Good, 306. DIGESTION. which is carried to the thoracic duct, and being there united with the CHAP. VI. chyle changes it into blood; but neither of these doctrines is to be con- SECT. III. sidered as established. (g) Dr. Bostock and others have inferred that as there are instances of continuing life and health notwithstanding the total destruction of the spleen, it is not absolutely essential to life, and that consequently the office of the spleen is only of a supplementary nature, and though occasionally useful, is not indispensable.(h) The spleen may be affected by turgescence or enlargement, called Diseases of parabysma splenicum; (i) and although this organ is not to be regarded spleen. as vital, or one of sensibility, and it be wholly wanting, or be extirpated without affecting life, yet the more the spleen exceeds its natural size, the greater is the emaciation of the individual and the impairment of his health;(k) because being a diverticulum, it retains blood that ought to go to the general fund. The spleen may also be inflamed, but it is less subject to it than many other of the abdominal viscera. (1) It may also become ossified, and have tubercles formed in its substance, but there is seldom suppuration in it. (m) So the spleen, like the liver, may be Injuries to ruptured by blows, falls, wounds, or other violence, and which will spleen. generally prove fatal.(n) with the small and great in Having thus considered the digestive organs, the intestinal canal, and Collateral the collateral or solid viscera, it may be proper to notice the peritoneum, parts conwith its folds, the mesentery, the mesocolon, and omenta. The viscera nected of the abdomen, which we have thus considered. are fixed in their position by an extended serous membrane, the peritonæum, already mentioned.(0) forming numerous folds, which are called ligaments. It is closely adapted testines, to the liver, gall bladder, stomach, intestines, spleen, and on the pelvic viscera. From the great arch of the stomach it forms a very extended fold, which invests the front of the intestines, called the great omentum or epiploon; and the great omentum is reflected back to form attachments for the small intestines in the centre of the abdomen, and called the mesentery, and a large duplicature around it for the large intestines is called the mesocolon, and ligaments of the colon, the spleen, the liver, bladder, and rectum. A very cursory notice of the peritoneum will suffice, for it is comparatively uninteresting and unimportant, whether physiologically or surgically. Its precise course is most difficult to trace; it is not to be classed amongst the viscera of the abdomen, though, in fact, it invests or surrounds them. The mesentery, mesocolon, and omenta, are ligaments and plicæ, or folds, formed by the peritoneum. The mesentery and mesocolon are primary processes reflected off from the spine upon the intestines, whereas the omenta, (from the Latin omentum, and signifying the caul in which the bowels are wrapped,)(p) are secondary processes of the peritonæum reflected from the surface of the stomach and intestines. The mesentery is the ligament of the small intestines, whilst the mesocolon is the ligament of the large intestines; and the omenta are floating membranes of great delicacy expanded over the surface of the small intestines, and attached to the great arch of the stomach. (g) (g) 1 Good, 25, 26. (h) 2 Bost. 399. (i) 1 Good, 325; 3 Bell, 351; see diseases of spleen in general, Cyclop. tit. Spleen. (k) 1 Good, 325, 326. (1) 2 Good, 371. (m) 3 Bell, 351. (n) Paris & Fonbl. 66; Ryan, Med, Jour. 179. (0) Ante, 183; and see its diseases, (p) Ventriculus atque intestina pingui CHAP. VI. The Mesentery is formed by a doubling of the peritoneum, which is SECT. III. detached forward, and includes the intestines, as in a sling. It is named DIGESTION. from its situation in the middle of the intestines, and is divided into two Of the me- parts, one connecting the small intestines, and retaining the name of sentery in mesentery; the other the great intestines, and termed mesocolon (r) The general. proper Mesentery begins at the last turn of the duodenum, and runs obliquely downwards, and towards the right side along the vertebræ of the loins, to the first, second, and third of which it is chiefly connected. Between the two layers of the mesentery are enclosed a considerable quantity of cellular substance and fat, with the numerous blood vessels, nerves, lacteals, and glands of the jejunum and ileum. Its anterior edge is much more extensive than the posterior, being plaited and folded, and corresponding with the convolutions of the intestines to which it is fixed.(s) The surface of the mesentery has a moisture exuding from its pores. Its use is to give a smooth surface and to strengthen the intestines, and in a great measure to limit the degree of their distention.(t) The mesenteric glands are of the greatest importance, for the chyle absorbed by the lacteal vessels, before it is carried into the thoracic duct, is deposited in them, and there at least delayed until it is again absorbed and carried forward.(u) The mesenteric glands. The mesocolon. The omen ral. The mesocolon is the continuation of the mesentery, which, after reaching the lower extremity of the ileum, contracts and obtains this name. It follows the course of the great intestines, and fixes them in their right place. Below the right kidney it is narrow and firm, and forms the right ligament of the colon. Opposite to that kidney it appears to be lost by the immediate adhesion of the colon to the duodenum in front of the kidney. It then turns across and forms a broad expansion, which encloses the arch of the colon at its interior edge, and behind it separates and encloses the anterior part of the duodenum, and is fixed to the spine. It adheres a little to the under part of the extremity of the stomach, and then descends over the left kidney, at the lower part of which it forms the left ligament of the colon. It afterwards adheres to the left psoas magnus muscle, and forms a loose fold, which retains the sigmoid flexure of the colon. At the last vertebra of the loins it forms the mesorectum, which by degrees becomes narrower and disappears towards the under part of the pelvis, the rectum being then immediately connected to the os sacrum. Between the layers of the mesocolon are placed the arteries, veins, and nerves, with the absorbents and glands of the colon.(v) The mesentery in general suspends, connects, and retains the intestines in their places, furnishes them with an external coat, receives their glands, vessels, and nerves, and allows the two last to be properly distributed. (x) The omentum, or caul, (y) formerly called epiploon, from its seeming to ta in gene- float on the intestines, is a fine membranous bag, intermixed with much fat, and covering a large portion of the anterior surface of the abdominal viscera. It is divided into omentum gastro colicum, and omentum colicum, the former common to the stomach and colon, the latter proper to the colon; they are, however, a continuation of one and the same substance. (z) ~ The omentum is the principal seat of fat. (a) The uses of the DIGESTION. omenta seem to be, that they fill up the inequalities which arise from the CHAP. VI. rounded forms of the viscera, and lubricate and give mobility to the in- SECT. III. testines.(6) But the idea of the oil or fat exuding is unfounded, nor is it subservient to the liver.(c) Sometimes the omentum is affected with Diseases a peculiar disease, termed parabysma omentale or turgescence of the and injuomentum, being an indurated and diffused tumour.(d) The omentum ries to may suffer strangulation, and require operation and peculiar treatment in hernia epiplocele.(e) Sometimes the omentum will become the seat of excessive accumulation of fat.(ƒ) omenta. licum or magnum in particular. The omentum gastro colicum, or magnum, consists of an anterior and of the posterior part, each of which is formed of two membranes, ultimately omenta united. In young subjects, the omentum forms a distinct bag, but, in gastro coold people, the layers of which it is composed, become more or less incorporated. The anterior layer is a continuation of the peritoneal coats produced by the upper and under surfaces of the stomach.(g) This omentum is a peculiar process of peritonæum arising immediately from the external coat of the stomach.(h) The longest and most remarkable process of peritoneum is this omentum. It is a large, empty, delicate sac, hanging from the large curvature of the stomach, extended over the greater part of the small intestines, applying itself closely to their convolutions, and in some measure insinuating itself into their interstices.(i) The omentum colicum arises from the right part of the arch of the co- of the lon, in the same manner as the other part of the omentum arises from omentum the stomach, and sends downwards and to the right side a cuneiform process to be connected to the cæcum. (k) colicum in general. Besides these omenta, there is a membrane much smaller, situated Other between the liver and stomach, termed omentum hepato gastricum, or Omenta. omentum minus of Winslow. It passes from the fore part of the sinus of the porta to the under and back part of the liver, to be connected to the whole edge of the small curvature of the stomach, and to the beginning of the duodenum. It is composed of two layers, but is thinner, has less fat, and is more uniform in its structure than the omentum magnum, and also differs from it in having no reflection upwards.(/) (b) El. Blum. 349. (c) 3 Bell, 266; El. Blum. 349. (g) 2 Horn. Anat. 12, 13; 3 Bell, 264. (i) Id. 349, where see a full description. CHAPTER VII. OF THE FUNCTION OF ABSORPTION; ITS ORGANS AND PARTS. CHAP. VII. SECT. I. TION, Section I. Definition and Description. Section II. Its Organs and parts. First, The Lacteals. Secondly, The Lymphatics. parts are solved, absorbed, form of all parts of the body. Of Cutaneous Absorption. Thirdly, The Glands Conglobate or Fourthly, The Thoracic Duct. Sixthly, Diseases in, or Injuries to, SECT. I. SECTION I-THE DEFINITION AND GENERAL DESCRIPTION. Ir has been truly observed, that absorption is one of the most imporDEFINI- tant functions in the system, and one of the most frequent channels through which disease is caused, perpetuated, or removed, and that the AND GENE- importance of entertaining accurate ideas, as to the channels through RAL DE which the noxious agents affect the system, must be manifest.(b) TION, SCRIPTION. (a) General sorbent lymphatic vessels. The function of absorption, from the Latin term, is defined by its name signifying sucking up, or imbibing, and consists in certain vessels and description organs, viz. lacteals, lymphatics, glands, and thoracic duct, termed absor of the ab- bents, receiving or taking up certain fluids, and transporting them from one part of the system to the other. The fluids thus taken up are, prinfunction, cipally, two, namely, the chyle and the lymph, the former received by the and of the lacteals, and the latter by the lymphatics. The immediate objects of the lacteal and action of those sets of vessels is essentially different; that of the lacteals is to convey the chyle from the small intestines into the thoracic duct, and from thence into the subclavian vein, to be there intermixed with the general mass of the blood, in order that it may directly serve for the nutrition of the body;(c) whilst the lymphatics, it is supposed, serve to remove what is useless or noxious, and to dispose of it in such a manner, that it may either be applied to some secondary purpose of utility, so that nothing useful may be wasted, and that what would otherwise be injurious may be discharged from the system. (d) The glands collect and retain for a time the absorbed lymph, and probably, in some degree, influence its cha (a) See an excellent practically useful article on Absorption, Amer. Cyclop. Prac. Med.; and see, in general, Elliotson's Blumenbach, 360 to 377; 2 Bost. chap. xi. p. 423 to 480; 5 Good, 168 to 192; 2 Bell, 322 to 365; Jackson, Prin. Med. 382 to 403; and Coop. Dict. tit. Absorption; see an account of the discovery of the absorbent system, El. Blum. 374 to 376; 2 Horn. Anat. 292 to 302; 2 (c) 2 Bost. 423. |