Julie Fay, age 12, of Lilburn, Ga., for her question:.for her question:

WHAT DOES THE SPLEEN DO?

The spleen is a glandlike organ that helps filter the body's blood. It lies below the diaphragm, to the left of the stomach and a bit behind it. In adults it is about five inches long and three to four inches wide. It weighs about seven ounces.

Foreign substances are filtered from the blood by the spleen, much as a lymph gland filters foreign substances from the lymph. The spleen also serves as a graveyard for injured red blood cells. When the body needs extra blood during exercise or hemorrhage, the spleen contracts and squeezes out some of the blood cells it has stored.

The spleen may form red blood cells in unborn babies, but it does not do so after birth.

The spleen is only a helper. If it is removed through an operation, no noticeable ill effects result.