A network of vessels, tissues, organs, and cells that helps maintain fluid balance, transport certain substances, and support immune defense.
The lymphatic system includes lymphatic vessels, lymph nodes, the spleen, thymus, and other lymphoid tissues. Lymphatic vessels collect excess fluid and substances from tissues and return them to the bloodstream. The system also transports immune cells and helps filter material through lymph nodes.
The lymphatic system plays an important role in immune surveillance by providing locations where immune cells can encounter and respond to foreign substances and infectious agents.
QUICK FACT
The lymphatic system is not simply a drainage system. It is also an important part of the body’s immune defense.
COMMONLY CONFUSED WITH
Immune system: The lymphatic system is an important component of immune defense, but the immune system is broader and includes many cells, molecules, tissues, and organs beyond the lymphatic system.
SEE ALSO
- Lymphocyte
- Lymph Node
- Immune Cell
- Immunity
- Thymus