Lymphatic nodes are small glands located in various parts of the human body. Described by some as bean-shaped, the primary lymph nodes are in the neck, under the arm, and in the groin, though individuals typically has over 500 of these glands. The main reason that we have lymphatic nodes is to filter lymphatic fluid, which may contain unwanted substances such as viruses and bacteria.
Considered to be part of the immune system, lymphatic nodes catch the unwanted substances so that they do not lead to infection and health complications. Once the lymph nodes filter the bacteria or viruses, the unwanted substances are then destroyed by white blood cells. White blood cells are found in both the blood and the spinal fluid and are also considered to be an important part of the immune system. These cells also assist in the healing of wounds.
Another reason that we have lymphatic nodes is to assist in the transmission of lymph. This is a clear fluid that moves proteins and nutrients through the blood and to tissues throughout the body. Lymph is also responsible for carrying some white blood cells.
Doctors, physicians, and other health specialists may also evaluate lymphatic nodes in clinical contexts to assist with diagnosis and treatment. The glands in the neck, for example, may become swollen or inflamed when a patient is suffering from a throat infection. More serious illnesses may also be determined by observing the health of a patient's lymph nodes, both through physical examination and through tests such as biopsies.
Since lymph nodes perform a critical role in immune response, they often become involved when local cancers metastasize. When evaluating disease progression in patients suffering from cancer, specialists use the lymphatic nodes to determine the severity of disease. In some cases, the lymph nodes cannot be evaluated. This is often symbolically represented by the health specialist with an "NX." "N0" is used to designate an earlier stage of cancer in which the lymph nodes are evaluated and it has been determined that they are not infected.
Lymphatic nodes that are represented by N1, N2, or N3 after examination are infected by cancer. The corresponding numbers refer both to the number of lymph nodes infected by cancer cells and the extent to which the cancer has spread. Doctors use these designations to determine how severe a patient's disease is and what treatment options will best assist in halting its progression.