What are lymph nodes? What is their function in human body?
A lymph node is an ovoid organ of the lymphatic system and of the adaptive immune system, that is widely present through out the body.
The lymphatic vessels are punctuated at intervals by small lymph nodes. Lymph is very similar to blood plasma. It contains lymphocytes and other white blood cells. Lymphocytes are concentrated in the lymph nodes. Lymph nodes are secondary lymphoid organs, enclosed in a fibrous capsule and are made up of an outer cortex and an inner medulla.
The primary function of lymph nodes is the filtering of lymph to identify and fight infection. They act as filters for foreign particles and cancer cells.
They also have clinical significance. They become inflamed or enlarged in various diseases ranging from trivial throat infections to life threatening cancers.
The spleen and tonsils are the larger secondary lymphoid organs that serve similar functions to lymph nodes, though the spleen filters blood cells, rather than lymph.