DIRECTIONS FOR LABORATORY WORK 799 



differential characteristics between the pars fundica and the pars pylorica 

 of the stomach. 



(5) Study an injected specimen of cat's stomach showing the blood 

 supply of the several tunics. Sketch (252). 



(6) Study demonstration preparations (methylene blue technic) of 

 cat's stomach showing the nerve supply. Note especially the myenteric 

 and the submucous plexuses. Sketch (253). 



(H) THE SMALL INTESTINE (Intestinum 



(1) Study l.p. a longitudinal section through the area of transition 

 from the pylorus to the duodenum. Compare part for part. In the 

 duodenum note: a, villi; b, intestinal glands (crypts of Lieberkiihn) ; 

 c, duodenal (Brunner's) mucous glands; and d, the plica circulares 

 (valvulse conniventes) . Sketch (254). Enumerate the chief criteria 

 for distinguishing between the duodenum (small intestine) and the 

 pyloric portion of the stomach. 



(2) Sketch h.p. : a, a villus in transverse and longitudinal sections 

 (255); b, intestinal gland (256). Identify a cell of Paneth. 



(3) Study l.p. a stained transverse section through the jejunum or 

 the ileum. Sketch (257) at the level of a Peyers patch (agminated 

 nodule). Difference in shape of villi in the three segments of the small 

 intestine? Distribution of lymphoid tissue? Presence of glands in the 

 tela submucosa? 



(I) THE LARGE INTESTINE (Intestinum crassum). 



(1) Draw l.p. (258) a portion of a stained section of the colon, 

 including the four tunics. How does it differ in grosser features from 

 the small intestine? In the relative abundance of goblet cells? of sol- 

 itary lymph nodules? of granule cells of Paneth? Note the tenia? coli 

 of the tunica muscularis. 



(J) THE VERMIFORM APPENDIX (Processus vermiformis). 



(1) Study a transverse section of a normal human appendix. Note 

 the relative abundance of the crypts of Lieberkiihn and the solitary 

 lymph nodules; and the differences in the lamina muscularis mucosae 

 and the tunica muscularis, as compared with the colon. Sketch (259). 



(K) CAECUM. 



Study a longitudinal section through the area of transition (cwcum) 

 from the ileum to the ascending colon. Note the iliocolic valve. Note 



