THE STOMACH. 



909 



The oblique fibres are limited chiefly to the cardiac end of the stomach, where 

 they are disposed as a thick uniform layer, covering both surfaces, some passing 

 obliquely from left to right, others from right to left, round the cardiac end. 



The areolar or submucous coat consists of a loose, filamentous, areolar tissue, 

 connecting the mucous and muscular layers. It supports the blood-vessels previous 

 to their distribution to the mucous membrane : hence it is sometimes called the 

 vascular coat. 



The mucous membrane is thick ; its surface smooth, soft, and velvety. In the 

 fresh state it is of a pinkish tinge at the pyloric end, and of a red or reddish- 

 brown color over the rest of its surface. In infancy it is of a brighter hue, the 

 vascular redness being more marked. It is thin at the cardiac extremity, but 

 thicker toward the pylorus. During the contracted state of the organ it is thrown 

 into numerous plaits or rugge, which for the most part have a longitudinal direc- 

 tion, and are most marked toward the lesser end of the stomach and along the 

 greater curvature (Fig. 492). These folds are entirely obliterated when the organ 

 becomes distended. 



/Structure of the Mucous Membrane. When examined with a lens the inner 

 surface of the mucous membrane presents a peculiar honeycomb appearance, from 



FIG. 494. Pyloric gland. 



FIG. 495. Peptic gastric gland. 



being covered with small shallow depressions or alveoli of a polygonal or hexagonal 

 form, which vary from -^ to ^ of an inch in diameter, and are separated by 

 slightly elevated ridges. In the bottom of the alveola are seen the orifices of 

 minute tubes, the gastric glands, which are situated perpendicularly side by side 

 throughout the entire substance of the mucous membrane. The surface of the 

 mucous membrane of the stomach is covered by a single layer of columnar epithe- 

 lium ; it lines the alveoli, and also for a certain distance the mouths of the gastric 

 glands. This epithelium commences very abruptly at the cardiac orifice, where the 

 cells suddenly change in character from the stratified epithelium of the oesophagus. 

 The cells are elongated, and consist of two parts, the inner or attached portions 

 being granular, and the outer or free parts being clear and occupied by a muco- 

 albuminous substance. 



