What is the purpose of the human spleen?

BRY2K

The function of the spleen, a lymphatic organ located in the abdominal cavity, was not known until fairly recently. Though the spleen and the "black bile" it secretes have had various meanings in the folk medicine of various cultures since ancient times, its actual functions remained a mystery until the mid-20th century. In humans, the spleen consists of two different tissue types — red pulp and white pulp — with two distinct functions. The spleen is a very important organ, and asplenia, a condition in which the spleen is not present either congenitally or due to removal in surgery, has been linked to an increased predisposition to certain infections. The spleen also serves as an emergency reservoir of blood. In some animals, it stores red blood cells, while in humans, it stores platelets, the clotting agent in blood. The spleen also has a few minor functions. In the human fetus, the spleen is a secondary site of red blood cell production until the fifth month of gestation, though after birth, red blood cells are only produced in the bone marrow. Other metabolic products, however, are produced in the spleen throughout adulthood; namely, opsonins, properdin, and tuftsin. http://www.wisegeek.com/what-does-the-spleen-do.htm Dec 30 07, 6:41 AM

zbeckabee

The spleen is an organ located in the abdomen of the human body, where it functions in the destruction of old red blood cells and holding a small reservoir of blood. It is regarded as one of the centers of activity of the reticuloendothelial system (part of the immune system). http://en.wikipedia.org/wiki/Spleen Dec 30 07, 8:33 AM