740 DISEASES OF THE SPLEEX. 



Fluxion causes 1. Splenic enlargements in the acute infectious 

 diseases; the enlargement in typhus and intermittent fevers, in the 

 acute exanthemata, puerperal fever, septicaemia, etc. We do not know 

 whether the increased flow of blood into the spleen in these diseases 

 be due to a relaxation of the already yielding tissue of the spleen, or 

 to a paralysis of the muscular elements of the walls of the vessels, and 

 of the trabeculae. (Jaschkowitz observed that, after dividing the 

 branches of the sympathetic going to the spleen, it became very large 

 and excessively vascular. If he only divided some of the nerves, the 

 hyperaemia was limited to the parts of the spleen supplied by the 

 divided nerves.) The manner in which the infected blood may alter 

 the elasticity of the tissue of the spleen, or the contractility of its 

 muscular elements, is just as obscure. The swelling of the spleen in 

 intermittent fever has been explained by saying that, during the chill, 

 the circulation on the surface of the body is decidedly disturbed, and, 

 on account of the ischaemia of the skin, the internal organs, and among 

 these the spleen particularly, are overloaded with blood. But these 

 conditions are of only secondary importance, as is proved by the fact 

 that the amount of splenic enlargement is not at all in proportion to 

 the severity of the chill, that the spleen also enlarges during the hot 

 stage, and finally, because enlargement of the spleen occurs from 'mala- 

 rial infection when there is no fever. 2. Fluxion to the spleen occurs 

 hi anomalies of menstruation / we might repeat of this form all that 

 was said of the occurrence of hyperaemia and haemorrhage from the 

 gastric mucous membrane arising from the same cause. 3. Injuries, 

 inflammations, and neoplasiae hi the spleen induce fluxions. We may 

 best observe this form of hyperaemia in haemorrbagic infarction of the 

 spleen (see Chapter IV.). 



There is a physiological engorgement of the spleen a few hours 

 after every meal, that is, at the time when the lateral pressure in the 

 portal vein is greater from the increased supply of blood coming from 

 the filled intestinal veins, and when the flow of blood from the splenic 

 vein is obstructed. Abnormal congestion is induced by obstruction 

 and closure of the portal vein, such as occur in numerous diseases of 

 the liver, as cirrhosis, pylephlebitis, and others. Since most of these 

 last a long while, besides the hyperaemia of the spleen, we usually find 

 its results which will be spoken of in the next chapter. Engorgement 

 of the spleen is far less constant and excessive in heart and lung dis- 

 eases, where the flow of blood from the vena cava is obstructed, and 

 this obstruction extends through the vessels of the liver tc* those of 

 the spleen. It is difficult to explain why, in spite of .excessive cyano- 

 sis and general dropsy, the spleen often remains of normal size, and 

 not very vascular in heart and lung disease. It is even more remark- 



