Abstract
The compartments and lymphocyte subsets of the human spleen differ from the spleen of rodents. The red pulp removes old red cells or malformed erythrocytes found in spherocytosis. The high blood flow is also necessary to filter bacteria like pneumococci from the blood. Without a spleen or after splenectomy, there is the risk of a fatal postsplenectomy sepsis. Therefore, these patients have to be vaccinated. Splenic particles can regenerate. The spleen is very important in lymphocyte recirculation and lymphocyte production. The marginal zone B lymphocytes are unique and important for B memory in man.