Lymph System and Lymph Nodes
As a part of the immune system, the lymph system is a process of carrying lymph fluid to lymph nodes via lymph vessels. Instead of circulating in a closed loop like blood vessels, it flows only in a single direction. The lymph fluid can transport wastes products from cells to the bloodstream for excretion. Beyond that, Lymph fluid also contains white blood cells (lymphocytes) to fight off foreign invaders.
All the lymph fluid passes through kidney bean-shaped lymph nodes for filtration. Humans have approximately 600 lymph nodes throughout the body, mainly distributed in the neck, armpits, groin, around the guts, and between the lungs. They are soft structures and generally can’t be felt. However, lymph nodes will become visible when inflamed and turn swollen.