CHAPTER XI 



THE DIGESTIVE TRACT OF THE FOWL AND ITS 

 FUNCTION 



Note to Teacher: Hold postmortem and demonstrate all parts of the 

 digestive tract of a hen. A laying hen preferred. For reference reading 

 see Anatomy of the Domestic Fowl, published by W. B. Saunders Co., 

 Philadelphia, Pa. 



135. The Organs Through Which Food Passes. The food 

 is taken up by the beak and, by a backward movement of the 

 tongue and a jerk of the head, is thrown back into the throat 

 and passes down the first part of the esophagus (No. 2, Fig 24). 

 The esophagus gives passage to the food to the crop (No. 3, 

 Fig. 24). The crop is simply a storehouse for food. From the 

 crop the food passes through the second portion of the esophagus 

 to the proventriculus, a spindle-shaped organ just in front of the 

 gizzard (No. 4, Fig. 24). The proventriculus secretes a strong 

 acid and pepsin, in which the food soaks before it passes to the 

 gizzard. From the proventriculus the food goes on to the giz- 

 zard (No. 5, Fig. 24). The gizzard is provided with strong 

 muscles and has a thick pad lining it. In the gizzard the food 

 is ground and is mixed with a ferment secreted by glands in 

 the gizzard walls. This ferment is pepsin and aids in digesting 

 the food so that it can be used by the body. From the gizzard 

 the food passes into the loop or the first portion of the small 

 intestine (No. 6, Fig. 24). Here it is mixed with a fluid which 

 is manufactured by the pancreas (No. 13, Fig. 24). From the 

 small intestinal loop the food passes into the floating or free 

 portion of the small intestine, where it is mixed with a fluid 

 secreted by the intestinal wall. All of these fluids contain 

 ferments which digest the nutrients of the food and resolve them 

 into a state in which they can be absorbed by the blood and 



