694 A MANUAL OF ANATOMY 



The Pyloric orifice, or pylorus, is on a lower level and more 

 anterior plane than the cardia, and, moreover, it usually lies to 

 the right of the median line. Relatively to the vertebral column 

 it is on a level with the upper part of the body of the first lumbar 

 vertebra, and it is opposite the tip of the ninth right costal cartilage. 

 When the stomach is empty, the pylorus usually lies about | inch 

 to the right of the median line, but this distance is increased during 

 distension to i^ or 2 inches, or even more. The pylorus may be 

 said to lie about 4 inches below the junction of the seventh right 

 costal cartilage with the sternum. Its level may also be stated 

 as being midway between the interclavicular notch on the upper 

 border of the manubrium sterni and the upper border of the sym- 

 physis pubis. 



Peritoneal Relations. — The stomach is almost completely invested by peri- 

 toneum, the anterior surface deriving its covering from the peritoneum of the 

 general cavity, and the posterior surface from that of the small sac. The 

 parts uncovered by peritoneum are as follows : a narrow line along the small 

 curvature between the two layers of the gastro- hepatic omentum for the 

 passage of the gastric and pyloric arteries ; a narrow line along the great 

 curvature between the two layers of the gastro-colic omentum for the passage 

 of the right and left gastro-epiploic arteries ; and the uncovered area or 

 trigone. This latter area is situated on the posterior surface, bslow, and a little 

 to the left of, the cardiac orifice. It is about 2 inches in breadth, and rather 

 less from above downwards, its shape being triangular. This part of the 

 stomach is in contact with the left crus of the diaphragm, and sometimes with 

 the left suprarenal capsule. The reflection of the peritoneum around this 

 area from the stomach to the diaphragm is known as the gastro-phrenic liga- 

 ment, which lies on the left side of the lower end of the oesophagus. 



For the structure and development of the stomach, see pp. 781, 



798. 



Position, Connections, and Component Parts of the Intestinal 

 Canal. — The intestinal canal commences at the pyloric end of the 

 stomach and terminates at the anus. It is divided into small 

 intestine and large intestine. 



The small intestine commences at the pyloric extremity of the 

 stomach, and terminates in the right iliac fossa by opening obliquely 

 into the large intestine. It measures fully 23 feet in length, and is 

 divided into three parts, which, from above downwards, are called 

 the duodenum (twelve fingers' breadth), jejunum (' empty '), and 

 ileum (' coiled'). The duodenum is from 10 to 11 inches in length, 

 and its limits are the pyloric extremity of the stomach, and the 

 left side of the body of the second lumbar vertebra. Being very 

 deeply placed, its position and connections will be described further 

 on (p. 731). Of the remainder of the small intestine the upper 

 two-fifths represent the jejunum, and the lower three-fifths the 

 ileum. There is no evident external mark of separation between 

 the three divisions of the small intestine, so that they merge imper- 

 ceptibly into each other; but there are internal characters which 

 serve to distinguish these divisions. On the left side of the body 

 of the second lumbar vertebra, where the duodenum terminates in 

 the jejunum, the bowel describes a bend in a downward and for- 



