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lymph node

(limf node)
A small bean-shaped structure that is part of the body’s immune system. Lymph nodes filter substances that travel through the lymphatic fluid, and they contain lymphocytes (white blood cells) that help the body fight infection and disease. There are hundreds of lymph nodes found throughout the body. They are connected to one another by lymph vessels. Clusters of lymph nodes are found in the neck, axilla (underarm), chest, abdomen, and groin. For example, there are about 20-40 lymph nodes in the axilla. Also called lymph gland.
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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