The Mesothelioma SOS Glossary - Lymph Nodes

Lymph nodes are components of the lymphatic system which act as internal filters that collect and destroy bacteria and viruses. Humans have approximately 500-600 lymphocytes or lymph nodes, which multiply rapidly when the body is exposed to an infection. Clusters of lymph nodes are found in the groin, underarms, chest, neck and abdomen. Additionally, lymph nodes tend to swell in size when an infection is present. Lymph nodes are bean shaped, and range in size from a few millimeters to 2 cm. While lymph nodes are known to swell when infection is present, many lymph nodes remain enlarged due to past infections. However, when checking for infection doctors will usually check to see if lymph nodes are enlarged. Lymph nodes become enlarged when they recognize that an antigen is present. Stimulation of the lymph node by an antigen causes the lymph node to speed the migration of T-cells to approximately ten times their normal speed, which in turn results in the characteristic swelling of the lymph node.