lymphatic system
Meaning of lymphatic system: The lymphatic system is a network of vessels and organs that drains excess fluid from tissue and supports immune defense.
Definition of lymphatic system
The lymphatic system is a network of vessels, nodes, and organs that helps maintain fluid balance in the body and supports its immune defenses. Thin lymphatic vessels collect excess fluid, called lymph, that leaks out of blood vessels into surrounding tissue, and carry it through a series of lymph nodes before eventually returning it to the bloodstream.
Lymph nodes, scattered throughout the body, filter lymph as it passes through and contain immune cells that detect and respond to infection or other abnormal material carried in the fluid. The system also includes organs such as the bone marrow, thymus, and spleen, which produce and mature the white blood cells the lymphatic system relies on.
Because the lymphatic system both drains tissue fluid and carries immune cells throughout the body, it also provides a route through which infection or cancer cells can spread from one region of the body to lymph nodes and, from there, to other tissues.
Used in a sentence
Swollen lymph nodes were noted on examination, prompting evaluation of the lymphatic system for signs of infection.
Good to know
Because the lymphatic system provides a route for cells to travel between regions of the body, nearby lymph nodes are often examined to check whether an infection or cancer has spread beyond its original site.
Word origin
Where “lymphatic system” comes from
Formed from Latin lympha, meaning clear water or spring water, referring to the clear fluid the system carries.