Lymph Node
A lymph node, or lymph gland, is a small, bean-shaped organ of the immune system and lymphatic system. Lymph nodes are widely distributed throughout the body and are linked by lymphatic vessels, where they function as filters for foreign particles and are key sites for the initiation of adaptive immune responses. They house various immune cells, including lymphocytes such as B cells and T cells, as well as macrophages and dendritic cells.