Lymphatic system

The lymphatic system is a unidirectional network of vessels, lymph nodes, and associated lymphoid tissues that functions to return interstitial fluid, macromolecules, and cells from peripheral tissues to the central venous circulation. It is essential for maintaining extracellular fluid homeostasis, facilitating immune cell trafficking, and supporting immune surveillance and response.

The lymphatic system includes initial lymphatic capillaries, collecting lymphatic vessels, lymph nodes, and major ducts (such as the thoracic duct), which ultimately drain lymph into the venous system near the subclavian veins, and the spleen.