THE STOMACH 



1155 



the mucosa (Harvey and Bensley). The pyloric glands [gl. pyloricae] are branched tubular 

 glands occupying the pyloric region. Whether they are merely mucous or also secrete pepsin 

 is still in dispute. 



The interstitial tissue of the lamina propria contains diffuse lymphoid tissue and a few 

 small lymph nodules, especially in the pyloric region. The muscularis mucosae is a thin sheet 

 of smooth muscle lying just below the fundus of the glands and is composed of an inner circular 

 and an outer longitudinal layer. 



The tela submucosa (fig. 910) is a very loose areolar, vascular layer which permits the 

 wrinkling of the mucosa according to the degree of distention. 



The tunica muscularis contains three layers of smooth muscle (figs. 911, 912, and 913). 

 The outer or longitudinal layer [stratum longitudinale] is thickest along the lesser curvature, 

 and is continuous with the longitudinal fibres of the oesophagus and the duodenum. On the 

 anterior and posterior walls of the antrum pylori, the longitudinal fibres form thickened bands, 



Fig. 910. — Diagrammatic Section of the Stomach Wall Showing (A.) The Blood 

 vessels, (B) the Tunics, and (C) the Lj^mphatics. M, Mucosa. Mi, Muscularis mucosa;. S, 

 Submucosa. /, Circular, and O, longitudinal muscle layer. (Szymonowicz, after Mall.) 



M— 



Mi- 



the ligamenta pylori. The middle or circular layer [stratum circulare] is continuous with the 

 circular fibres of oesophagus and duodenum and surrounds the entire stomach. It is especially 

 thickened in the region of the pyloric canal, at the lower end of which it forms a thickened 

 ring-like band, the pyloric sphincter [m. sphincter pylori]. The inner or oblique layer [fibrse 

 obliquse] is composed of fibres continuous with the deepest circular fibres of the oesophagus. 

 They form an incomplete layer which encircles the fundus and passes obliquely downward 

 around the body of the stomach toward the greater curvature. 



The external tunica serosa is formed by the peritoneum, and has the smooth shiny appear- 

 ance and the structure typical for a serous membrane. 



Blood-vessels. — The stomach receives its blood-supply from many branches. From the 

 coeliac axis there is the left gastric artery, which runs along the lesser curve from left to right, 

 anastomosing with the right gastric branch of the hepatic. Along the greater curve run the 

 right and left gastro-epiploic arteries, anastomosing at the middle of the border, the left being 



