THE STOMACH. 



149 



Lesser Curvature, * is concave, and connected to the liver by the gastro- 

 hepatic omentum, and to the diaphragm by the gastro-phrenic ligament. 



GLsophageal Orifice, b is situated between the fundus and the lesser curva- 

 ture. It is funnel-shaped, and the highest part of the organ. 



Pyloric Orifice, k opens into the duodenum, ^and is guarded by the circu- 

 lar muscular fibres of the pylorus, which are aggregated into a circular 

 ring, projecting into the cavity, and with its covering fold of mucous 

 membrane, forming the Pyloric Valve. 



Describe its Structure. The Stomach has 3 coats, a 

 Mucous Coat, g lined with columnar non-ciliated epithelium, covered with 

 polygonal Alveoli, T |^ of an inch in diameter, containing the orifices of the 

 Gastric Follicles, When the stomach is contracted the mucous membrane lies 

 in longitudinal folds or Rugce, h one of which aids in forming the valve at 

 the pyloric orifice. 



Cellular or Sub-mucous Coat, contains the gastric vessels. 

 Muscular coat,f consists of longitudinal, circular, and oblique fibres. The 

 Longitudinal are continuous with those of the oesophagus and small intes- 

 tine, and are the most superficial. The Circular lie deeper, and over the 

 whole organ ; they form a sphincter valve around the pyloric orifice. (See 

 above.) The Oblique 

 Fibres lie deepest, 

 form ing two sets around 

 the oesophageal open- 

 ing, in continuation of 

 the circular fibres of 

 the oesophagus. 

 THE SEROUS INVEST- 

 MENT of the stomach is 

 derived from the perito- 

 neum, and covers the 

 whole external surface, 

 excepting the points 

 where the gastro- splenic, 

 greater and lesser omenta 

 are attached. It is usu- 

 ally, but incorrectly, described as a fourth coat of the stomach. 



Describe the Gastric Glands. They are of 3 kinds, the 

 Peptic Follicles, situated all over the stomach, but most numerous towards 

 the splenic end, are tubules lined with columnar epithelium in their upper 

 one-fourth, and filled with nucleated cells in their deepest parts. 



FIG. 70. 



