MOVEMENTS OF THE ALIMENTARY CANAL. 719 



the sphincter again falls into tone until another peristaltic wave 

 approaches from the esophageal side. 



The Anatomy of the Stomach. The stomach in man belongs 

 to the simple type as distinguished from the compound stomachs 

 of some of the other mammalia, the ruminating animals, for 

 example. Physiological and histological investigations have shown, 

 however, that the so-called simple stomachs are divided into parts 

 that have different properties and functions. The names and bound- 

 aries of these parts can not be stated precisely, since they vary in 

 different animals, and, moreover, there is some want of agree- 

 ment among different authors regarding the nomenclature of 

 the parts of the stomach.* For the purposes of a physiological 

 description we may use the names indicated in the accompany- 

 ing schematic figure. The main interest lies in the separation of 

 the pyloric part of the stomach or antrum pylori from the main 

 cavity of the stomach. The line of separation is marked by a 

 fissure on the small curvature, incisura angularis (/. A.), and on the 

 large curvature by an abrupt change of direction. The pyloric part 



/w^ ( _. N 



-Fundua 



Pyloricfoartofsfont, 

 or antru/n bylori 



Position of 

 transverse 



Intermediate or 

 prepyloric reyion. 



Fig. 283. Schematic figure to show the different parts of the stomach. (After Retzius.) 



makes an angle, therefore, with the body of the stomach, and differs 

 from the latter in its musculature, the macroscopical and microscop- 

 ical characteristics of its mucous membrane, and in its functional 

 importance. Some writers divide the antrum further into a 

 pyloric vestibule, forming the larger part of the antrum, and a 

 pyloric canal, consisting of the narrower tube-like portion which 

 connects with the duodenum. The pyloric canal is short, about 

 3 cm., and is more marked as a separate structure in the stomach 

 of young children. The rest of the stomach falls into two sub- 

 divisions, the fundus and the corpus or body. The fundus is the 

 blind, rounded end of the stomach to the left of the cardia, or, in 

 a vertical position of the stomach, the portion that lies above a 

 horizontal plane passing through the cardia; the portion between 



* See His, "Archiv f. Anatomic," 1903, p. 345; also Cunningham, "Trans- 

 actions of the Royal Society of Edinburgh," 45, 9, 1905-06. 



