ORGANS OF DIGESTION 



139 



The large intestine consists of the cecum, colon, and rectum. 

 The cecum is the Ijlind conical projection at the beginning of 

 the large intestine. It is only one or two centimeters long. 

 There is no vermiform appendix in the 

 cat. The ileum opens into the large in- 

 testine at the junction of the cecum and 

 colon. An annular fold of mucous mem- 

 brane, strengthened by a sphincter muscle, 

 forms the ileocecal valve, which retains the 

 food in the small intestine until the 

 nutriment is absorbed (Fig. 66). 



The colon, extending from the cecum 

 to the rectum, is composed of the as- 

 cending, transverse, and descending parts. 

 The ascending colon lies on the right 

 side, the transverse extends crosswise, 

 connecting the ascending with the descend- 

 ing, which lies on the left side. The de- 

 scending colon terminates in the rectum, 

 which is five or six centimeters long. 



The waU of the alimentary canal is ^^^ ^^ _^ ^^^^^ 

 composed of three chief coats — mucous, section of the Mucous 



, , , Coat of the Stomach 



areolar, and muscular, these coats may between the Lines a 

 be seen by cutting transversely, with a ^^d c in Fig 61 Shows 



•^ ^ ^ -^ A Gastric Gland. X 



sharp scalpel, a portion of the stomach 250. Diagrammatic. 

 hardened in formalin. The mucous coat giand;^rcoiumnaT'ep^ 

 (Fig. 68) lines the lumen and contains thdiai ceils on the food 



, > . surface of the stomach; 



four typical structures: (a) an mner /, lumen of a gland; o. 

 epithelial layer, (b) a tunica propria sup- ^^^^^^^ ^'^ ^''^ ^^"• 

 porting (c) the secreting glands, and (d) 

 muscular layer — the muscularis mucosae — separating the 

 mucous from the submucous coat. The glands of the 

 mucosa vary much in the different portions of the canal. 

 The mucous coat of the esophagus of the cat is free 

 from glands, for the greater part, at least. In some animals 



