THE STOMACH. 



157 



ullated fibres are chiefly sympathetic and, therefore, are destined espe- 

 cially for the involuntary muscle and glands. Between the longitudinal and 

 circular layers of muscle they form a wide-meshed plexus, containing many 

 microscopic ganglia, that corresponds with the plexus myentericus of the 

 stomach and intestine, with which organs it will be described (page 163). The 

 mucous membrane receives nonmedullated fibres, from an indefinite plexus 

 within the submucous layer, which terminate within the tunica propria in 

 free endings, some threads entering the deeper layers of the epithelium. 



THE STOMACH. 



Being essentially a greatly dilated and modified segment of the digestive 

 tube, connecting the oesophagus and the small intestine, the walls of the 

 stomach agree in their general makeup with those of the other parts of the 



^ 



Mucosa 



Submucosa 



Muscularis 



Serosa 



- Gastric glands 



Muscularis 

 mucosae 



" " " J & K f "'* ^ 



^r^ossii^ 



Blood-vessel 



Oblique bundles 

 of nonstriated 

 muscle 



FIG. 196. Transverse section of human stomach, left third, showing general arrangement of coats. X 18. 



alimentary canal lying below the diaphragm. They consist, therefore, of 

 four coats the mucous, the submucous, the muscular, and the serous. 

 When moderately distended, the stomach is a somewhat flattened pear- 

 shaped sac, with the large end up and the point bent to the right. The 

 highest part of the stomach is called the/undus; the end joining the oesoph- 

 agus is the cardia, and that meeting the intestine fat Pylorus. 



The mucous coat, or mucosa, thickest near the pylorus (1.5-2 mm.) 

 and thinnest at the cardiac end (.35-. 55 mm.), is loosely attached to the 

 muscle by the submucous tissue and, possessing little elasticity, is easily 

 thrown into folds or rug eg when the other coats contract. During disten- 

 tion these folds are largely effaced, but under the more usual conditions are 



