DIGESTION 295 



The oesophageal groove, formed of two longitudinal 

 muscular folds, is a continuation of the lumen of the 

 oesophagus, which runs along the wall of the first three 

 compartments and ends in the abomasum. By this 

 means fluid food can pass directly from the oesophagus to 

 the abomasum. When the pillars are relaxed the groove 

 communicates with the rumen and the reticulum. 



The crop of the fowl is a dilatation of the oesophagus that 

 occurs at the root of the neck. It corresponds to the 

 rumen, reticuhim, and omasum of the ruminant. 



The Stomach is a dilatation of the alimentary canal. It 

 bulges out at the oesophageal end — the fundus. Towards 

 the outlet it tapers off to the pyloric canal. A strong 

 circular band of muscle between the stomach and intestine 

 controls the outflow of its contents. In the dog the fundus 

 is separated from the pylorus by a circular band of muscular 

 fibres — the prepyloric sphincter. The mucous membrane 

 is largely composed of tubular glands. Those at the 

 oesophageal end secrete hydrochloric acid and pepsin, those 

 at the pyloric end pepsin only. 



In the horse (fig. 145) the stratified squamous epithelium 

 of the oesophagus is continued into the stomach, and lines 

 nearly one half of the organ. Only the pyloric part and the 

 fundus are covered with the glandular mucous membrane. 

 The opening of the oesophagus to the stomach is small, and 

 partially occluded by folds of the lining membrane. 



The Small Intestine is a long convoluted narrow muscular 

 tube suspended in the folds of a membrane slung from the 

 spinal region of the body cavity. The mucous membrane is 

 projected into the lumen of the tube as a series of delicate 

 finger-like processes — the villi — which are covered by 

 columnar epithelium. 



There are two kinds of glands that secrete the intestinal 

 fluid — the succus entericus. 



(1) Lieherkuhn's follicles are found throughout the whole 

 small intestine. They are simple test-tube like glands 

 which open between the villi. 



(2) Briinners glands are found only in the upper part of 

 the small intestine. They are branching glands that pene- 



