I know that the spleen is related to the lymph system, but is that all it does?I know that it has monocytes in it which remove the dead erythrocytes but how do the monocytes determine which ones are dead and which ones are alive? I have had mononucleosis, which make the monocytes do something they are not supposed to I know, but how would it affect the spleen? When I went in to get it checked out the first thing they did was to determine whether my spleen was enlarged. It was, but why was it enlarged? I don’t really understand what I went through, (except that it was painful and I was always tired) it was a while ago. :D