His 



LIFE PROCESSES OF MAN 



Figure 184. — Pear- 

 shaped Human 

 Stomach. 



muscles, one extending lengthwise, the other around 



the esophagus, act together in forcing the food or water 



into the stomach. This explains why we 

 can drink from a brook when the head is 

 much lower than the stomach. 



Stomach. — In man the stomach is the 

 largest section of the digestive tube, and 

 it has a capacity of about three pints. 

 It is usually described as pear-shaped 

 although there is much variation in its 



form (Figures 184 and 185). At the point where the 



esophagus joins the stomach there is a muscular ring 



(cardiac valve, kiir'di-ak) which ordinarily prevents the 



food from passing again into the esopha- 

 gus. In vomiting, this valve becomes 



relaxed. The opening at the larger 



and lower end of the stomach is guarded 



by a similar valve (pyloric, 23i-16Vik) 



which serves to retain the food in the 



stomach until certain digestive changes 



have taken place. 



The intestine has two parts, a small, 



much coiled tube about an inch in 



diameter and about twenty feet long 



called the small intestine; and a large 



section about five feet long and four 



inches in diameter, bent in a rough 



p shape and called the large intestine. 



At the junction between these two miliar to physicians 



regions projects a short sac, the vermi- and is called the J_ 

 ■p y s ~- i' « j.* „ , shape. — Dr. C. F. 



jorm appendix (vermi-form ap-peiv- p ot t e r. 



diks). The disease called appendicitis 

 (ap-pend-i-si'tis) affects this organ. The large intes- 

 tine ends in a special region called the rectum. The 



Figure 185. — X-ray 

 Photograph of 

 Human Stomach. 



