PHYSIOLOGICAL ANATO1IY OF THE STOMACH. 209 



in anatomical descriptions are : a greater and a lesser cur- 

 vature ; a greater and a lesser pouch ; a cardiac, or cesopha- 

 geal opening; and a pyloric opening, which, leads to the 

 intestinal canal. The great pouch is sometimes called the 

 fundus. 



The coats of the stomach are three in number : the peri- 

 toneal, muscular, and mucous. By some, the fibrous tissue 

 which unites the mucous to the muscular coat is regarded 

 as a distinct covering, and is called the fibrous coat. 



Peritoneal Coat. This is simply a process of the perito- 

 neum, similar in structure to the membrane which covers the 

 other abdominal viscera. It is a reflection of the membrane 

 which lines the general abdominal cavity, which, on the 

 viscera, is somewhat thinner than it is on the walls of the 

 cavity. Over the stomach, the peritoneum is from -^\^ to 7 

 of an inch in thickness. It belongs to the class of serous 

 membranes, and consists of fibres of the white inelastic tissue, 

 mingled with a considerable number of elastic fibres. It is 

 closely adherent to the subjacent muscular coat, and is not 

 very abundantly supplied with blood-vessels and nerves. 

 Lymphatics have only been demonstrated in the subserous 

 structure. The surface of the peritoneum is everywhere 

 covered with regularly polygonal flattened cells of pavement 

 or tessellated epithelium, closely adherent to each other, and 

 presenting a perfectly smooth surface which is continually 

 moistened with a small quantity of watery secretion. An 

 important function of this membrane is to present a smooth 

 surface covering the abdominal parietes and viscera, so as 

 to allow of free movements of the viscera over each other and 

 against the walls of the abdomen. In the case of the nollow 

 viscera especially, this membrane, from its structure, must 

 give them considerable strength. 



Muscular Coat. Throughout the whole of the alimentary 

 canal, from the cardiac Opening of the stomach to the anus, 

 14 



