Why are lymph nodes important to the body?

Lymph nodes are structures in the lymphatic system. Your
lymphatic system is an extensive network of lymphatic vessels distributed all over the
body. Everyday we are exposed to pathogens that have the potential of causing us great
harm. The lymphatic system is part of our defense mechanisms or immunologic response
that fights off these pathogens and keeps us relatively healthy. The system as a whole
is comprised of lymphatic vessels, lymph nodes, lymphatic tissue like the tonsils,
thymus, and spleen. Basically, the system is a biological filter, the lymph nodes filter
the lymph as it passes through, the lymphatic fluid is then returned to the venous
circulation via the thoracic duct and right lymphatic duct. The lymph nodes are
important because they are located in clusters along the route that the lymphatic fluid
passes and remove these harmful substances from the lymph.