THE VISCERA. 221 



451. 3. The Spleen, lien, spleen, 



a spongy organ very rich in blood (blood gland) which lies deep 

 in the reg. hypochondr. sinistra, behind and to the left of the 

 fundus of the stomach, above the left kidney, in a fold of the 

 peritonaeum, and becomes displaced by the movements of the 

 diaphragm and stomach. Figure : semi-oval (also prismatic). 

 Colour: bluish or brownish red or even pale grey, by long 

 exposure to the air, rosy red. Weight: two to eight ounces 

 (in hypertrophy = ten to thirty pounds) ; specific grav. : 1*16. 

 Length : four to five inches ; breadth : two and a half to three 

 and a half; thickness : one to one and two-thirds. 



The external, convex, smooth surface, separated by the dia- 

 phragm from the ninth to the eleventh ribs, looks upwards and 

 backwards. 



The internal concave surface looks obliquely forwards towards 

 the Pancreas and fundus of the stomach, and presents, in about 

 the centre, a superficial oblong excavation, hilus lienalis, where 

 the splenic vessels enter and pass out, and lig. gastro-lienale is 

 attached. Before, the hilus is in contact with the fundus of the 

 stomach ; behind that, the left kidney and caps. sup. renales and 

 the tail of the Pancreas. 



The superior thick extremity lies Hinder the diaphragm ; the 

 inferior pointed extremity rests upon the angle of the colon 

 (transv. and descend.). The borders are sometimes deeply in- 

 dented, and thus present traces of a second spleen (lien, succentu- 

 riatus) or several, which in the foetus and children are frequently 

 observed. The posterior border, thick above, is adjacent to the 

 kidney, the anterior is applied to the stomach. 



Structure : 1. The proper substance of the spleen is a pultaceous, reddish 

 brown, granular mass, pulpa lienis, which consists of pencillate tufts of capil- 

 lary vessels, out of which veins pass, and which lies like a sponge in the 

 whitish cells of a fibrous membrane. 



2. The fibrous coat, tunica albuginea, forms the frame-work of the organ, 

 since it covers it externally, and sends prolongations into the Parenchyma, 

 like a net, especially at the hilus, where it forms sheaths for the vessels, and 

 accompanies their ramifications, so that the whole acquires a spongy 

 structure. 



White splenic corpuscles, corpuscula lienis Malpighi (not to be confounded 

 with the liquefying vesicles of Herbivora), lie, according to J. Miiller, inside 

 the red granules of the pulpa, and are seated upon the white sheaths of the 

 arterial branches, of which they are merely sprouts (according to Heusinger 

 blastema, formative matter). 



3. The serous tunic (peritonaeum) envelopes the whole spleen, even to the 

 Hilus, whore the lig. gastro-lienale comes over from the fundus of the stomach. 

 Lig. phrenico-lienale goes from the superior extremity of the spleen to the pos- 

 terior portion of the inferior surface of the diaphragm. Its internal surface is 

 firmly connected to the external of t. albuginea. 



