THE SPLEE]^'. 397 



superior mesenteric. Its blood is returned by the splenic and superior mesenteric 

 veins. Its lymjihatics terminate in tlie lumbar vessels and glands. The nerves 

 of the pancreas are derived from the solar plexus. 



THE SPLEEW. 



The spleen (figf. 282, r) is a soft highly vascular and easily distensible 

 organ, of a dark bluish or purplish grey colour. It is situated in the left 

 hypo-chondrium, between the cardiac end of the stomach, and the dia- 

 phragm. It is the largest of the organs termed ductless glands. 



The shape of the spleen is somewhat variable : it forms usually a 

 compressed oval mass, placed nearly vertically in the body, and having 

 two faces, one external, convex, and free, and which is turned to the left ; 

 the other internal and concave, which is directed to the right, and is 

 applied to the cardiac end or great cul-de-sac of the stomach : it also 

 presents an anterior sharper and a posterior blunter margin. 



The convex face of the spleen, smooth and covered by the peritoneum, 

 is in contact with the under surfiice of the left side of the diaphragm, 

 and corresponds with the ninth, tenth, and eleventh ribs. The internal 

 concave face is divided by a vertical fissure, named the Jiiliis (r), into 

 an anterior and posterior portion, both covered with peritoneum, con- 

 tinued round the borders from the convex surface. The anterior of 

 these two portions is the larger, and is closely applied to the stomach ; 

 the posterior is in a})position with the left pillar of the diaphragm and 

 left suprarenal capsule. The anterior border of the spleen is thinner 

 than the posterior, and is often slightly notched, especially towards the 

 lower part (see fig. 282). The lower end is pointed, and is in contact 

 with the left end of the arch of the colon (splenic flexure), and rests on 

 the costo-colic ligament. The position of the hilns corresponds with 

 the line of attachment of the gastro-splenic omentum, a fold of perito- 

 neum, continuous with the left border of the great omentum, attaching 

 the spleen to the left extremity of the stomach. Along the bottom of 

 this fissure are large openings, which transmit blood vessels, with 

 lymphatics and nerves, to and from the interior of the organ. In 

 some cases there is no distinct fissure, but merely a row of openings 

 for the vessels ; and in others the situation of the hilns is occupied 

 by a longitudinal ridge, interrupted by the vascular orifices. A por- 

 tion of variable extent behind the hilus, and towards its lower end, will 

 usually be observed deriving its peritoneal covering from the sac of the 

 omentum, at least in the young subject. 



The spleen varies in magnitude more than any other organ in the body ; and 

 this not only in different subjects, but, as may be ascertained by percussion, in 

 the same individual, under different conditions. On this account it is difficult or 

 impossible to state what are its ordinary weight and dimensions : in the adult it 

 measures generally about 5 or oh inches from the upper to the lower end, 3 or 4 

 inches from the anterior to the posterior border, and 1 or 1^ inch from its external 

 to its internal sm-face ; and its usual vohime, according to Krause. is from 9j 

 to li) cubic inches. In the greater number of a series of cases examined by Reid, 

 its weight ranged from 5 to 7 ozs. in the male, and was somewhat less in the 

 female ; but even when perfectlj- free from disease, it may fluctuate lietween 

 4 and 10 ounces. Gray states that the proportion of the spleen to the weight of 

 the adult body varies from 1 : ;)2() to 1 : 400. In the foetus the proportion is as 

 1 : 850. After the age of forty the average weight gradually diminishes, so that 

 in old age the weight of the spleen is to that of the body as 1 : 700. The specific 

 gi-avity of this organ, according to Haller, Soemmeniug, and Krause ;s about 



