CHAPTEK X. 



MOVEMENTS OF THE STOMACH. 



Character of the contractions of the muscular coat of the stomach Movements 

 in the cardiac and in the pyloric portion Mechanism of the movements of 

 the stomach Rumination, and regurgitation from the stomach Rumination 

 in the human subject Yomitmg Mechanism of vomiting Condition of the 

 stomach during the act of vomiting Action of the diaphragm in vomiting 

 Action of the abdominal muscles in vomiting Action of the oesophagus in 

 vomiting Summary of the muscular action which takes place in vomiting 

 Eructation. 



As the articles of food are passed into the stomach by the 

 acts of deglutition, the organ gradually changes its form, size, 

 and position. "When the stomach is empty, the opposite sur- 

 faces of its lining membrane are in contact in many parts, and 

 are thrown into numerous longitudinal folds. As the organ is 

 distended, these folds are effaced, the stomach itself becom- 

 ing more rounded ; and as the two ends with the lesser curv- 

 ature are comparatively immovable, the whole organ un- 

 dergoes a movement of rotation, by which the anterior face 

 becomes superior, and is applied to the diaphragm. At this 

 time the great pouch has nearly filled the left hypochondriac 

 region, and the greater curvature looks anteriorly, and comes 

 in contact with the abdominal walls. 



Aside from these changes, which are merely due to the 

 ingestion of food, the stomach undergoes important move- 

 ments, which continue until its contents have been dissolved 

 and absorbed, or have passed out at the pylorus. But while 

 these movements are taking place, the two orifices are guard- 

 ed, so that the food shall remain .for the proper time exposed 



