What are lymph nodes primarily involved in?

Lymph nodes play a crucial role in the lymphatic and immune systems primarily by filtering lymph and housing immune cells. As lymph fluid circulates through the lymphatic system, it passes through these nodes, which act as checkpoints. The lymph nodes contain lymphocytes, including B cells and T cells, that are essential for the immune response. When pathogens such as bacteria or viruses are detected in the lymph, these immune cells can activate to respond to the infection, initiating an immune response. This process helps to prevent the spread of infection throughout the body and is fundamental to maintaining immune health.

In addition to filtering harmful substances, lymph nodes also facilitate the production of antibodies by B cells and the activation of T cells, which are critical components of the adaptive immune system. Thus, their primary function revolves around both the filtration of lymphatic fluid to remove pathogens and the activation of the immune response, making them vital to immune defense.