Definition - What does Lymph Node mean?
A lymph node is part of the body's lymphatic system. The lymphatic system, of which the lymph nodes are one part, is a part of the body's circulatory system. However, the lymphatic system does not transport blood. Instead, this system carries a clear fluid called lymph. The lymph system play an important role in the body's immune defense. Lymph nodes are also called lymph glands.
WorkplaceTesting explains Lymph Node
The lymphatic system includes lymph vessels and nodes, as well as the tonsils, adenoids, thymus, spleen, and bone marrow. Stem cells in the bone marrow produce special white blood cells called lymphocytes that pass through the lymph system. A large vessel near the heart connects the lymph system to the rest of the circulatory system.
Similar to blood, the lymph fluid delivers oxygen and nutrients and removes carbon dioxide as it passes around and through vessels, capillaries, and tissues. Additionally, the lymph fluid collects harmful substances including bacteria, viruses, cancer cells, and toxins. The organs of the lymph system, including the lymph nodes, then serve to filter out these harmful materials. Once collected by the lymph system, these harmful substances are attacked by the lymphocytes.
Lymph nodes are often gathered in clusters. For instance, clusters of nodes can be found in the neck, groin and armpits. Sometimes the lymph nodes or other lymph organs, such as the tonsils, will become sore or swollen when the body is fighting an infection. This swelling is called lymphadenopathy or adenopathy.
While lymph nodes can filter cancer cells, the body is not always successful in destroying these cells. In some instances, the lymph system then becomes a vehicle through which cancer cells are spread to other parts of the body. This event is called metastasis. When cancer originates in the lymph nodes, the condition is called lymphoma.