Lümf

Lümf is a clear to pale yellow fluid that circulates through the lymphatic system. It originates as interstitial fluid that drains from tissue capillaries and enters lymphatic capillaries, where it becomes lymph. Lümf transports immune cells, particularly lymphocytes, and helps maintain fluid balance by returning excess interstitial fluid to the venous bloodstream. It may also carry absorbed fats from the intestine in the form of chyle, giving postprandial lymph a milky appearance.

The lymphatic system comprises lymph, lymphatic vessels, lymph nodes, and lymphoid organs such as the spleen, thymus, and tonsils, along with mucosa-associated lymphoid tissue. Lymph nodes act as immune surveillance sites, filtering pathogens and enabling activation of immune responses. Lümf from the intestines is transported by specialized vessels called lacteals in the gut and joins the general lymphatic flow as chyle.

Lymph is returned to the bloodstream mainly via the thoracic duct, which drains most of the body, and the right lymphatic duct, which collects lymph from the right side of the head, neck, and upper limb. The flow is aided by one-way valves, surrounding skeletal muscle contractions, and respiratory movements, producing a slow but continuous circulation.

Clinical relevance includes the risk of lymphedema when lymphatic drainage is blocked or impaired. Diseases affecting lymphoid tissues, such as lymphadenopathy and lymphoma, reflect the essential role of the Lümfatic system in immune defense and fluid homeostasis.