THE LARGE INTESTINE. 285 



intestine. Tliese are the intestinal villi. They are only found in the small intestine, and 

 are most abundant in its cephalic portion. 



The small intestine of the cat has no valvulse conniventes (Quain, A, 859 ; Gray, A, 

 773) ; but it is completely invested by peritoneum throutjliout its whole extent. In these 

 two particulars it diflFers from the intestine of man. 



§ 741. Microscopic Structure. — (A) Peritoneal or serous coat. (B) Muscular (unstriped) 

 coat : — (1) Longitudinal layer ; (2) circular layer. (C) Submucosa, areolar or loose con- 

 nective tissue coat. (D) Muscularis muccsfe of longitudinal and circular unstriped muscu- 

 lar fibers, some of which pass into the villi. (E) Mucous coat with villi and crypts of 

 Lieberklihn, covered with columnar epithelium ; Brunner's glands and Peyer's glands. 

 Quain. A, II, 358 ; Strieker, A, 380. 



§ 742. Intestinum amplum, az. — Large intestine (Fig. 77, § 719). 

 — The large intestine is the part of the alimentary canal extending 

 from the csecum to the anus, the caudal oj^ening of the canal. For 

 convenience of description, the large intestine is divided into four 

 parts, named in order : — CcBcitm, colon ascendens., colon iransver- 

 sum, colon descendens and rectum or terminal part. 



Exposure. — Turn the small intestine toward the left leg. 



(A) Ccecum (Fig. 80). — This is the somewhat conical blind sac at 

 the beginning of the large intestine. It lies on the right side and in 

 about the middle of the abdominal cavity. 



(B) Colon ascendens — Ascending colon. — This is the part of the 

 large intestine which extends cephalad from the csecum. 



Respecting the use of the terms cephalad and caudad in desig- 

 nating the position or direction of parts of the alimentary canal, 

 see § 91. 



TopograpMcaUy, the colon ascendens extends cephalad from 

 the csecum, but pliyslologlcally, that is, in resj^ect to the passage 

 of the contents, the entire colon is caudad of the csecum. 



It is quite short, and reaches nearly to the pylorus. Its dorsal 

 surface is in contact with the duodenum. 



(C) Colon transT.erswn — Transverse colon.— This is the continua- 

 tion of the preceding. It extends transversely across the abdomen 

 just caudad of the stomach. 



(D) Colon descendens and rectum.. — After extending nearly 

 across the abdomen from right to left, the large intestine passes 

 obliquely caudad, soon reaching the meson. It then extends cau- 

 dad along the vertebral column to terminate at the anus. The last 

 and straighter part is called the rectum. 



% 743. Obvious Structure of the Intextinum amplum. — If the large intestine is full of 

 feces, press the contents of a small part of the colon transversum aside and cut out a piece 



