THE SPLEEN 117 



THE SPLEEN 



The spleen presents no regular subdivision of parts which may_ 

 be studied separately and combined afterward, as we are able to do 

 with organs like the lung, liver, etc. The spleen is a ductless organ 

 or so-called gland, and the plan or scheme may, perhaps, be best 

 comprehended by following the blood distribution. 



The splenic artery enters the organ at the hilum, supported by 

 a considerable amount of connective tissue, and rapidly breaks into 

 smaller branches, from which the arterioles leave at right angles. 

 The arterioles quickly merge into capillaries, which form plexuses 



Capsule 



Traleculce 



Fein ^^*^K-AJ^tf\AA* Venous spaces 



Spleen-pulp 

 Capillaries 



FIG. 81. DIAGRAM. SHOWING THE COURSE OF BLOOD IN THE SPLEEN. 



throughout the different portions of the organ. Here we meet with 

 an anomalous structure. 



The capillaries, instead of uniting to form venules, as in the 

 usual vascular plan, empty their contents into small chambers or 

 sponge -like cavities the venous spaces. The blood, after filtering 

 through the venous interstices, is collected in larger, irregular, 

 vein -like channels, which finally conduct the blood into the veins 

 proper and out of the spleen. The tissue containing this vascular 

 arrangement is called splenic pulp. 



The fibrous capsule which envelops the spleen sends trabeculae 

 within, which form a framework; and from this fibrils are sent off, 



