322 ANATOMY IN A NUTSHELL. 



beginning, the inferior pancreatico-duodenalis, which, with the superior pan- 

 creatico-duodenaJis, forms as arch which lies in the concavity of the duodenum 

 and which supplies it. 



The blood is returned by means of the superior mesenteric vein which, 

 with the splenic forms the portal vein. 



The lymphatics form a continuous series, which is divided into two sets — 

 thai of the mucous membrane and that of the muscular coat. The lymph- 

 vessels of both sets form a copious plexus and end in the mesenteric lacteals. 



The nerve supply of the small intestine is by means of the superior mesenteric 

 plexus, which is continuous with the lower part of the solar plexus. The 

 branches follow the blood vessels, and finally form two plexuses, one (Auer- 

 bach's) which lies between the muscular coats; and another (Meissner's) in the 

 submucous coat. 



The follicles of Lieberkuhn are found in the large and small intestine. 



The large intestine (intestinum crassum) is about a quarter as long as the 

 small intestine. It is called large on account of its diameter, being about two 

 and a half inches in its broadest part. It begins at the right and lower portion 

 of the abdomen, passes upward and backward to the under surface of the liver, 

 thence across the belly to the spleen, from this point downward and forward to 

 the left and lower part of the abdomen, here it makes a number of curves, and 

 finally plunges into the pelvis at its back part, and ends close to the perineum, 

 near the inner opening of the anal colon. Its divisions are the caecum, ascend- 

 ing, transverse, descending colon, sigmoid flexure, and rectum. 



The glands of the small intestines or mesenteric glands (100-150) lie between 

 the layers of the mesentery among the meshes formed by the superior mesenteric 

 vessels, their size varying from that of a pea to that of a small almond. They 

 are largest and most numerous near the duodenum and the ileo-colic valve. 



The \csscls of the small intestine or lacteals, are of two kinds, viz., super- 

 ficial, placed between the layers of the muscular coat, or between the muscular 

 ami peritoneal coats, and running longitudinally; and deep, placed in the sub- 

 mucous tissue and running transversely around the gut with the mesenteric 

 vessels. They pass between the layers of the mesentery and then, in two or 

 three large trunks, into the thoracic duct. 



Tho caecum lies in the right iliac fossa; from this point the ascending colon 

 passes to the liver. Here it forms the hepatic flexure, then passes transversely 

 across the belly below the stomach, and here the splenic flexure is formed, 

 then ii passes downward, forming the descending colon. In the left iliac fossa it 

 forms the sigmoid flexure, and then passes through the pelvis as the rectum. 



The large intestine has four coats with the same arrangement as the stomach 

 and small intestine: serous, muscular, areolar, mucous. 



The large intestine has the crypts of Lieberkuhn and solitary glands. It 

 has no villi, no valvulse conniventes, no glands of Brunner, no patches of Peyer. 



The vermiform appendix is a blind process given off from the caecum, vary- 

 in man from three to six inches. (Plate CLLY.) 



The opening of the small intestine into the large is provided with promi- 

 nent lips which project into the cavity of the latter, and oppose the passage of 



