Swollen Lymph Nodes

Swollen Lymph Nodes Overview

Lymph nodes (erroneously called lymph glands) are a part of the lymphatic system, a component of the body's immune system. Swollen lymph nodes may signal an infection.
There are several groups of lymph nodes, which are small, bean-shaped, soft nodules of tissue. The ones most frequently enlarged or swollen are found in the neck, under the chin, in the armpits, and in the groin. There is also a large group of lymph nodes in the chest, which are sometimes found to be enlarged on X-rays or CT scans.

• The lymphatic system consists of nodes and ducts spread throughout the body. They bring the lymph [the tissue fluid surrounding the cells, which contains white blood cells (lymphocytes), fluid from the intestines (chyle), and some red blood cells] back into the circulation through the veins. Lymph contains a concentration of infectious and other foreign substances (antigens).

• Lymph nodes are small clusters of cells, surrounded by a capsule. Ducts go into and out of them. The cells in lymph nodes are lymphocytes, which produce antibodies (protein particles that bind foreign substances including infectious particles) and macrophages which digest the debris. They act as the "cleaner" cells of the body.

• The lymph nodes are a major site where foreign substances and infectious agents interact with the cells of the immune system. A major cluster of the lymph nodes is the spleen, which, apart from other functions, also helps fight infections and responds to foreign substances in the body.