186 ANATOMY OP THE ABDOMEN, ETC. 



The coats of the stomach, as in the rest of the alimen- 

 tary canal, are four in number, viz : peritoneal, muscular, 

 cellular, and mucous. The peritoneal coat envelops it 

 entirely. The muscular coat is made up of numerous and 

 well-marked fibres, disposed in longitudinal, circular, and 

 oblique directions. The mucous coat is movable, and 

 slides upon the muscular, from which it is separated by the 

 cellular coat ; if not fully distended it will therefore be 

 thrown into ruga* by the contraction of the latter ; its sur- 

 face is characterized by a sort of granulated appearance 

 due to the follicles with which it is provided. At the 

 pyloric extremity the mucous membrane forms a valve 

 called the pylorus; this is sometimes a complete ring, at 

 others merely two crescentic folds ; the muscular ^b 

 beneath form a sort of sphincter, and the entrance to the 

 duodenum may be closed by their contraction. The color 

 and condition of the mucous coat is variously modified by 

 the contents of the stomach and by post-mortem changes. 



THE SPLEEN. 



The SPLEEN is situated beneath the cartilages of the ribs, 

 at the cardiac extremity of the stomach, with which it is 

 connected by means of the gastro-splenic omen turn ; it is also 

 held in contact with the diaphragm by a suspensory perito- 

 neal ligament; its connections, however, are not very strong, 

 and it may easily be torn out from its position with the 

 fingers. It is completely invested by peritoneum, which is 

 closely adherent, and presents a smooth surface, convex 

 externally, and concave internally. The upper end of the 

 spleen is larger than the lower ; the posterior border is 

 blunt and rounded, the anterior comparatively sharp, and 

 containing one or more notches. The concavity of the 

 spleen admits the arteries, and gives exit to the veins, 

 and that portion in relation with* these is called its Mlus. 

 The splenic artery, of large size, divides at its entrance 

 into several branches ; the splenic vein, also of large size, is 

 joined by the gastric, and superior, and inferior mesenteric 

 veins, and terminates in the portal vein. Its nerves are 

 derived from the solar plexus. 



A section of the spleen exhibits a reticulated parenchyma 

 of very elastic nature, from the meshes of which large 

 quantities of blood may be squeezed or washed. In its 

 tissue, pearly bodies are sometimes seen, not unlike miliary 

 tubercles ; these are called the corpuscles of the spleen. 





