1160 



DIGESTIVE SYSTEM 



Gastroptosis is a very common abnormality in which the body of the stomach extends 

 vertically downward to the umbilicus, or lower, forming a sharp bend beyond which the pyloric 

 portion turns upward to reach its termination. This form is especially common in women, 

 due to tight lacing. 



Fig. 919. — Serial Radiographs Taken at Short Intervals, Showing Diastole 

 (Phases 7-10) and Systole (Phases 1-6), and the Progression toward the Pylorus of a 

 Four-cycle Type of Gastric Peristalsis. Fundus of the stomach not shown. (Cole.) 



Comparative.— 'J'lie primitive .stomach i.s perhaps merely a receptacle for food, true digestive 

 glands bcuig absent in many of the fishes. Tlie vertebrate stomach is a dilated sac of variable 

 form, but is typically somewhat loojK'd, with cardiac and pyloric segments. In birds, there is 

 a peculiar arrangement, correlated with the absence of teeth. The stomach is divided into an 



