1074 



THE ORGANS OF DIGESTION. 



inches) ; breadth, 8 cm. ; thickness, 3 cm. (Sappey). In children its proportion 

 to body-weight is 1 to 350 ; in adults 1 to 320 ; in old age 1 to 700. 



Its average cadaveric weight in the above ten specimens was 195 gm. If 

 filled with blood its physiological weight would be 225 gm. (or 7 ounces). Its 

 specific gravity is 1.054, showing greater density than the liver. Its volume is 

 200 to 300 cc. 



Its color in the living animal is dark red and probably the same in living man. 

 After death it is dark purple to a grayish red, due to the presence of venous 

 blood. 



In consistence it is soft and distensible and liable to laceration. 

 Form and Relations. The spleen may be ellipsoid, tongue-shaped in length, 

 or it may be rectilinear with its four corners rounded off. An internal view of 



tho model by His (Fig. 612), shows it 

 to be somewhat broader above than 

 below, while typical forms presented 

 by Luschka show two types both larger 

 below. One is rectangular which is 

 most frequent, and one is oval (Fig. 

 686). 



Three surfaces may be distin- 

 guished, phrenic or external, basal, and 

 internal, which is subdivided by the 

 intermediate ridge (mar go intermedium) 

 into an an terior gastric portion (super- 

 ficies gastrica), and a posterior renal 

 portion (superficies renalis). 



There are two margins, anterior 

 or crenated (margo crenatus, and pos- 

 terior (rnargo obtusus}. 



The spleen lies obliquely with its 

 long axis placed deep in the left hypo- 



chondrium and nearly parallel to the ribs. It lies between the concave surface 

 of the diaphragm, placed to the left, behind and above, and the fundus of the stom- 

 ach, placed to the right and in front. It is above the left kidney and splenic 

 flexure of colon (Fig. 680). This figure will repay study as we do not always 

 appreciate that the suprarenal capsule and kidney and spleen rise nearly to the 

 cardia with the pancreas, transverse colon, and splenic flexure in immediate 

 contact. 



Its large convex phrenic surface lies against the costal part of the diaphragm 

 and looks upward, backward, and to the left or even a little inward above. It is 

 covered by the ninth, tenth, and eleventh ribs, but separated from them by the 

 peritoneum, diaphragm, costo-phrenic sinus, and in part by the left pleura and 

 lung. In some cases the left lobe of the liver extends between this surface of 

 the spleen and diaphragm. This is normal at birth when the hepatic surface of 

 the spleen is the biggest of all. 



The internal surface, directed toward the abdominal cavity is divided by a 

 prominent ridge into two parts, of which the posterior is narrow and the anterior 

 broad. 



The hilus of the spleen may be on the ridge, but is usually anterior to it. It 

 is represented by an irregular longitudinal row of depressions, in which the arteries 

 and nerves enter and through which the lymphatics and veins emerge. 



The surface posterior to the ridge is the renal surface, flat and not reaching 

 as high as the gastric surface, it is turned inward and downward toward the left 

 crus of the diaphragm, and is in contact with the upper and outer margin of the 

 left kidney, and usually the suprarenal capsule. 



The gastric surface, broad and concave, is directed inward and forward. 

 When the stomach is distended in the greater part of its extent, this surface lies 



Lower end 



FIG. 686. The two type-forms of the human spleen. 

 A. Rhomboidal form of spleen. B. Oval form of spleen. 

 (Luschka.) 



