ORGANS AND PROCESSES OF DIGESTION 151 



contraction of all the muscles of the stomach, together with 

 the contraction of the walls of the abdomen. During these 

 contractions the pyloric valve is closed, and the muscles of 

 the esophagus and pharynx are in a relaxed condition. 1 



The Small Intestine. This division of the alimentary 

 canal consists of a coiled tube, about twenty-two feet in 

 length, which occupies the cen- 

 tral, lower portion of the abdomi- 

 nal cavity (Fig.' 71). At its 

 upper extremity it connects with 

 the pyloric end of the stomach 

 (Fig. 70), and at its lower end it 

 joins the large intestine. It 

 averages a little over an inch in FIG ; 70 ._ Passage from 

 diameter, and gradually dimin- stomach into small intestine. 



isheS in Size from the Stomach Illustration also shows arrange- 

 to the large intestine. The first ent of mucous T^T in 



the two organs. D. Bile duct. 



eight or ten inches form a short 



curve, known as the duodenum. The upper two fifths of 

 the remainder is called the jejunum, and the lower three 

 fifths is known as the ileum. The ileum joins that part of 

 the large intestine known as the caecum, and at their place 

 of union is a marked constriction which prevents material 

 from passing from the large into the small intestine (Fig. 

 73). This is known as the ileo-ccecal valve. 



The mucous membrane of the small intestine is richly 

 supplied with blood vessels and contains glands that secrete 



1 Perhaps the simplest method of inducing vomiting is that of thrusting a finger 

 down the throat. To make this method effective the finger should be held in the 

 throat until the vomiting begins. An emetic, such as a glass of lukewarm salt 

 water containing a teaspoonful of mustard, should also be taken, and, in the case 

 of having swallowed poison, the vomiting should be repeated several times. It 

 may even be advantageous to drink water and then vomit it up in order to wash 

 out the stomach. 



