ABDOMINAL CAVITY 361 



anterior, posterior, and intermediate angles. It is triangular 

 in outline and concave in contour, and it rests upon the left 

 flexure of the colon and upon the phrenico-colic ligament. 



The diaphragmatic surface is the largest of the four sur- 

 faces. It is separated from the gastric surface by the notched 

 anterior border, from the renal surface by the posterior 

 border, and from the colic surface by the inferior border. It 

 rests against the left part of the posterior portion of the 

 diaphragm, by which it is separated from the lower parts of 

 the left lung and pleura, and from the ninth, tenth, and 

 eleventh ribs. 



Of the several borders which separate the different surfaces 

 from one another the anterior, the posterior, and the inferior 

 are the most conspicuous. The anterior border lies between 

 the diaphragmatic and the gastric surfaces. It extends from 

 the superior to the anterior angle. It is crossed by two or 

 more notches which can be felt, through the abdominal wall, 

 when the spleen is enlarged, and which serve, therefore, for 

 purposes of identification. T\*& posterior border runs from the 

 superior to the posterior angle, and separates the diaphrag- 

 matic from the renal surface. It is occasionally notched. 

 The inferior border, which runs from the anterior to the posterior 

 angle, separates the diaphragmatic from the colic surface. 



Of the four angles the anterior is the most prominent and 

 distinct. It lies at the junction of the anterior and the 

 inferior borders, at the level of the eleventh rib in the mid- 

 axillary line, and is the most anterior part of the spleen. 



The spleen is entirely surrounded by peritoneum, and 

 it is attached to two of the neighbouring viscera by folds 

 of that membrane: (i) To the fundus and the vertical part 

 of the body of the stomach by the gastro-splenic ligament, 

 and (2) to the anterior surface of the left kidney by the 

 lieno-renal ligament. Both the ligaments are attached to 

 the spleen along the margins of its hilum (Fig. 135). It is 

 also attached by the splenic artery to the coeliac artery, and 

 by the splenic vein to the portal vein. It is supported in 

 position not by its peritoneal and vascular attachments, but 

 by the general intra-abdominal pressure, which is due to the 

 tonic contraction of the abdominal muscles, and which com- 

 presses the adjacent viscera against it, and also by the 

 phrenico-colic ligament, upon which its inferior border and 

 part of its inferior surface rest. 



