STRUCTURE OF STOMACH. 339 



short distance before the pylorus, and the constricted part is styled 

 the pyloric canal (Jonnesco). 



The cardiac opening, which communicates with the oesophagus, is Cardiac 

 placed two or three inches from the most prominent part of the opemngs? 

 fundus, and is funnel-shaped towards the cavity of the organ. The 

 pyloric orifice opens into the duodenum, and is guarded internally 

 by a muscular band (pylorus), at this spot the stomach is slightly 

 constricted externally, and a firm circular thickening can be felt. 



The anterior, or upper, and the posterior, or lower, surfaces are Surfaces, 

 somewhat flattened when the viscus is empty, but round when it is 

 distended, and the parts in contact with them have been referred 

 to (p. 300). 



The upper border or lesser curvature is concave, except for a short Small 

 distance at the pyloric end. The lower border or greater curvature is 



FIG. 126. DIAGRAM OF THE MUSCULAR FIBRES OP THE STOMACH. 

 The external and middle layers are partly removed. 



a. External or longitudinal fibres. e. Oblique fibres, more numerous, 



6. Middle or circular. on the left of the cardiac orifice, 



c. Sphincter of the pylorus. and covering the great end of the 



d. Oblique fibres on the right of stomach, 

 the cardiac opening. 



much longer, convex, and when the organ is distended forms at the and large, 

 pyloric end a slight projection to the right, which has been named 

 the antrum pylori or small cul-de-sac. 



STRUCTURE. In the wall of the stomach are four coats, viz. serous, Four strata 

 muscular, fibrous, and mucous ; and belonging to these there are 

 vessels, nerves, and lymphatics. 



Serous coat. The peritoneum gives a covering to the stomach, and The serous 

 is adherent to the surface except at each margin, where an interval 

 exists corresponding with the attachment of the small and large rent - 

 omentum: in these spaces are contained the vessels, nerves, and 

 lymphatics. During distension of the stomach the spaces above 

 mentioned are much diminished. 



Z 2 



