164 



NORMAL HISTOLOGY. 



intercellular clefts or canals in many places afford direct commu- 

 nication between the parietal cells and the lumen of the tube. The 

 parietal cells are irregularly distributed from the fundus to the 



FIG. i 



Transverse sections of peptic glands from stomach of dog: A, plane of section passes through 

 ducts near free surface ; a, lumen of glands ; b, surrounding fibrous stroma of mucosa ; B, plane of 

 section passes through fundi near terminations of tubules ; the sections of the latter are arranged in 

 groups separated by connective tissue. , 



neck of the gland ; but they are especially numerous in the vicinity 

 of the neck. These cells are larger than those lining the lumen, 

 polygonal or triangular in outline, and possessed of a pale, faintly 

 granular protoplasm surrounding a round or oval 

 nucleus. Iji^re4)arationj5.pX^hviman_ stomach, the 

 parietal cells are not infrequently the most con- 

 spicuous and best denned, since the central cells \ 

 are prone to disintegrate. 



On approaching the pyloric ring, the simple 

 tubular peptic glands are gradually replaced by 

 the compound glands, until, near the intestinal 

 opening, these alone are present. 



The pyloric glands are characterized by their 

 relatively long, wide ducts into which the several 

 divisions of the body open ; the tubular com- 

 partments are wavy and tortuous, and frequently 

 end in slightly expanded extremities. The duct 

 is lined by tall columnar epithelium, the cells be- 

 coming lower and broader as they approach the 

 neck and towards the fundus. The cells contain 

 finely granular protoplasm, and do not secrete 

 mucus, but a thin albuminous fluid. Parietal or 

 acid cells do not occur in the pyloric glands, being 

 confined to the true peptic glands. 



The gastric glands, while very uniformly dis- 

 tributed through all parts of the stomach, are 

 arranged in groups, the individual tubules of 

 which are separated by very delicate partitions of the connective 



c/ 



Portion of peptic 

 gland of dog, highly 

 magnified : a, a, the 

 central or chief cells 

 next the lumen (c) ; 

 b, b, the parietal or 

 acid cells connected 

 with the lumen of the 

 tube by short lateral 

 branches which extend 

 to the cells. 



