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spleen

(spleen)
An organ that is part of the lymphatic and blood systems. The spleen filters the blood to help destroy microorganisms and get rid of old or damaged red blood cells. It also makes lymphocytes (white blood cells) and stores blood cells. The spleen is located on the upper left side of the abdomen under the ribs and above the stomach.
Lymphatic system; drawing shows the lymph vessels and lymph organs, including the lymph nodes, tonsils, thymus, spleen, and bone marrow. Also shown is the small intestine (one site of mucosal-associated lymphoid tissue). There are also two pullouts: one showing a close up of the inside structure of a lymph node and the attached artery, vein, and lymph vessels with arrows showing how the lymph (clear, watery fluid) moves into and out of the lymph node, and another showing a close up of bone marrow with blood cells.Enlarge this image in new window
The lymph system is part of the body's immune system and is made up of tissues and organs that help protect the body from infection and disease. These include the tonsils, adenoids (not shown), thymus, spleen, bone marrow, lymph vessels, and lymph nodes. Lymph tissue is also found in many other parts of the body, including the small intestine.
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