| XXX | (258) | XXX |
258 A N A T O M Y. Part VL crural veffels, which they involve, and are gradually loft is a continuation of the cefophagus; the other joins the inteftinal canal, and is called pylorus. in their courfe downward. To thefe four produ&ions of the cellular fubftance of The great extremity of theitomach is in the left hythe peritoneum, we may add a fifth, which is fpread on pochondrium, and for the moft part immediately undex the neck of the bladder, and perhaps a fixth, which ac- the diaphragm. companies the inteftinum return. All thefe elongations The fmall extremity of the ftomach does not reach to pafs out of the cavity of-the abdomen, and may be the right hypochondrium. It bends obliquely backwafd. termed external, to diftinguifh them from others that toward the upper orifice, fo that the pylorus lies about remain in the abdomen, and are called internal, of which two fingers breaddi from the body of tire vertebrae immediately under the fmail portion of the liver, and coahereafter. The great blood-veflels, that is, the aorta and vena fequently lower down, and more forward than the ocava, are likewife involved in this cellular fubftance of ther orifice by alrnoft the fame diftance. the peritonaeum. In a word, it involves immediately According to this natural fituation, the ftomach, efpe-. and feparately all the parts and organs which are com- ciafty. when full, lies fo as that the great curvature, is monly faid to lie in the duplicature of the peritonaeum. turned more upward than downward, and the frnail curIt has, neverthelefs, productions of its own, but they vature more backward than upward. One of the lateral convex fides is turned upward, the. are very different from thofe of the cellular fubftanee ; other downward; and not forward and backward, as they for they run from without, inward, that is, they advance in dead bodies, where the inteftines do not fupfrom the convex fide of the great bag of the peritonaeum, appear in their natural fituation. into the cavity of that bag, fome more, feme lefs, and partThethemftomach is compofed of feveral parts, the chiof of alfo in different manners; as if the fides of a large which are the different which form its fubftance, ball or bladder were thr aft inward into the cavity of the to which anatpmifts giveftrata the name of tunicas or coats. ball or bladder.. Thefe coats are commonly reckoned to be four in numOf thefe internal elongations or introprefiions of the ber, the outer or common, the flelhy or mafcular, the true lamina of the peritonaeum, fome are fimply folded, nervous aponeurotic, and the villous or inner coat; .and like a duplicature • fome are expanded like inverted bags they are orafterwards fubdivided feveral ways. Or facculi to contain fome vifeus ; fome begin by a fimple The firft or outermoft coat is fimply membranous, beduplicature, and are^afterwards expanded into a cavity, ing oneof the internal prodniftions of the peritonasum. which contains fome organ; fome are alternately extend- The fecond or mufcular coat is-made ed in the form of fimple duplicatures, and of cavities; planes of fibres, which may all be reduceduptooftwo,feveral, one and laftly, fome form only a fmall eminence on the inner external, the other internal. I he external coat is longitufurface of the great cavity of the peritonaeum. though in different r.efpedts, following nearly the The chief ufes of the peritonaeum are, to line the ca- dinal, of the curvatures and convexities of the ftovity of the abdomen, to invert the vifeera contained in direffion
- and the internal plane is tranfverfely circular.
that cavity as in a common bag, to fupply them with mach Between the outer and inner planes, round the fu•particular coats, to- form productions, ligaments, con- periour orifice, there are two diftinff planes, about the nexions, folds, vaginae, 6'c. of a finger, and very oblique, which furround The fine fluid which tranfudes through the whole in- breadth this orifice in oppofite direftions, and interfeift each oternal farface of the peritonaeum, prevents the inconve- ther where they meet on the two lateral fides. niences which might-arife from the continual frictions Along middle of each lateral fide of the fmall and motions to which the vifeera of the abdomen are extremity,thethere funs a tendinous or ligamentary flat expofed either naturally or by external impulfes. portion, above a quarter of an inch in breadth, which terminates in the pylorus. Thefe two portions lie beVENTRICULUS,*or STOMACH. tween the common and mufcular coats, and adhere very ftrongly to the firft. The ftomach is a great bag or refervoir, fituated partly Between the fame two coats, there is a cellular in the left hypochondrium, and partly in the epigaftrium. fubftance which adheres very clofely to the external coat, The figure of the ftomach is like that of a bag-pipe, and infinuates itfelf between the fleihy fibres of the feoblong, incurvated, large and capacious at one end, and cond, all the way to the third. fmall and contracted at the other. The third coat, called commonly tunica nervofa, fuThe curvature of the ftomach gives us occafion to di- ftains, on its convex fide, a very large reticular diftriftinguiih two arches in it; one large, which runs along bution of capillary veflel.s and nerves. On the concav^ the greateft convexity ; and one fmall, direCtly oppofite fide, it feenis to be of a very loole texture, and as it were to the former. The fides of the ftomach, are the two fpungy or filamentary, containing a great number of lateral portions which lie between the two arches. fmall glandular bodies, efpecially near the fmall curvaThe ftomach has two extremities, one large, and one ture and fmall extremity of the ftomach. fmall like a crosked funnel. It has two openings, cal- The fourth coat of the ftomach is termed villofa, be-, led the orifices of the itomach, one between the great caufe, when it fwims in clear water, fome have imagined extremity and the fmall curvature, the other at the end they faw fomething in it like the pile of velvet. of the fmall or contracted extremity. The firft opening Thefe two coats are of a larger extent than the two, fqrmer.
