56 UNIVERSITY OF MISSOURI STUDIES 



its junction with the body, is in close relation anteroextern- 

 ally with the splenic flexure of the colon (Plates XVI, 

 XVII, XXVIII and XXXII). 



THE SPLEEN 



The spleen appears in Plates XIII to XVI and XXVIII, 

 XXIX, XXXI, XXXII, XXXIII and XXXV. It lies in the 

 left hypochondriac region upon the diaphragm and posterior 

 abdominal wall opposite the ninth, tenth and eleventh ribs. 

 The upper pole is at the level of the lower border of the 

 ninth thoracic vertebra, and the lower pole at the level of 

 the lower border of the first lumbar vertebra. Upon the 

 anterior body wall the upper pole is at the level of the 

 lower border of the fifth rib in the midclavicular line, 8 

 cm. from the midline, and the lower pole in the eighth inter- 

 costal space, about 11 cm. from the midline. The organ is 

 ovoid in outline. Its long axis is 11 cm. in length and a 

 little more nearly vertical than the tenth rib, inclining from 

 above downward, outward and forward. 



The external or diaphragmatic surface is directed back- 

 ward in the upper half and outward in the lower half, and 

 is in contact with the diaphragm (Plates XIV, XV and 

 XVI). The upper part of this surface is in relation with 

 the posterior part of the base of the left lung (Plate XIII). 



The upper pole is separated from the posterior and ex- 

 ternal part of the inferior surface of the left lobe of the liver 

 by a portion of the fundus of the stomach. The upper pole 

 and the greater part of the external and gastric surfaces 

 are covered with peritonaeum. The posterior (internal) 

 border is bound to the diaphragm. The anterior (external) 

 border is free in its upper three-fourths, and adherent to the 

 splenic flexure in its lower fourth. 



