John Delay, age 11, of Chester, Pa., for his question: '
WHAT DOES THE SPLEEN DO?
A spleen is a large, glandlike organ in the body. It helps to filter the body's blood.
Your spleen is located below the diaphragm, to the left of the stomach and a little behind it. In an adult it measures about five inches long and from three to four inches wide. The spleen weighs about seven ounces.
Much as a lymph gland filters foreign substances from the lymph, the spleen helps filter foreign substances from the blood. And the spleen actually 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 this after birth.
The spleen is a soft and spongy organ. It has a deep red color and it crumbles easily.
The organ has a fold of peritoneum as a covering, the same membrane that lines the abdominal cavity. The principal cells of the spleen are similar to those in the lymph glands.
The spleen is thought to be only a helper of other glands and organs. It may be removed from the body without any noticeable ill effects.
Doctors sometimes find it necessary to remove the spleen. Sometimes a disease centers in the organ and causes it to enlarge.
In certain other diseases, the spleen works so hard at destroying worn out blood cells that it also destroys healthy red blood cells and causes anemia.
Sometimes the spleen also destroys blood platelets which help in the clotting of blood. When too many platelets are destroyed, the patient may bleed into the tissues. In all these cases, the spleen has to be removed by a surgical operation.
In some infections, such as malaria, the spleen may become very large. Enlargement of the spleen may also occur in leukemia.
Because of its storage of blood, injuries such as may happen in a highway accident or contact sports are likely to cause severe bleeding, which sometimes can be stopped only by removing the spleen. This operation is also done for a hereditary or acquired condition in which the spleen becomes enlarged and destroys some of the blood cells necessary for clotting.
With the spleen gone, the liver, white cells and bone marrow work overtime to replace its functions, and the patient goes on much as before.
Injury to the spleen's supporting tissues can cause a condition called wandering spleen, in which it moves about in the abdomen. In some persons, bits of spleen called accessory spleens have been found scattered throughout the abdominal cavity.