66 



EXPERIMENTAL PHYSIOLOGY 



XLI. — ^Microscopic Anatomy of the Digestive Tract 



(Optional). 



Apparatus. — Prepared slides of the cross sections of the walls 

 of the esophagus (middle part), stomach (pyloric section), small 

 intestine (injected blood vessels); compound microscope. 



Directions. — ^Make drawings of each section studied and 

 label the parts. See Figs. 30 and 31. 



Fig. 30. — Vertical Section 

 of the Coats of the 

 Stomach: d, surface of 

 mucous membrane, and 

 mouths of gastric folh- 

 cles; m, gastric tubuli, 

 or follicles; mm, dense 

 connective tissue; sm, 

 sub-mucous tissue; cm,, 

 transverse muscular fi- 

 bers; Im, longitudinal 

 muscular fibers; s, fi- 

 brous, or serous, coat. 



/•J 



Fig. 31. — Section of Injected Small Intestine 

 of Cat: a, b, mucosa; g, villi; i, their absorb- 

 ent vessels; h, simple follicles; c, muscularis 

 mucosae; d, sub-mucosa; e, e', circular and 

 longitudinal layers of muscle; /, fibrous coat. 

 All the dark lines represent blood vessels 

 filled with an injection mass. 



