Lymfekarene

Lymfekarene, the Danish term for lymphatic vessels, are thin-walled vessels that form a network to transport lymph, a clear fluid derived from interstitial fluid. They are a central component of the lymphatic system, which helps regulate tissue fluid balance, support immune surveillance, and absorb certain nutrients.

Structure and types: Lymphatic vessels begin as lymphatic capillaries in nearly all tissues. These capillaries have overlapping endothelial cells that act as one‑way flaps, allowing interstitial fluid and proteins to enter but preventing backflow. The capillaries merge into larger collecting lymphatics, which possess smooth muscle in their walls and valves to propel lymph toward the venous system. Along the way, lymph passes through lymph nodes, where immune cells survey and filter the fluid. From there, lymph travels into trunks and ducts, most notably the thoracic duct and the right lymphatic duct, before draining into the venous circulation at the subclavian veins. In the small intestine, specialized vessels called lacteals absorb dietary fats and fat‑soluble vitamins.

Function: Lymfekarene transport lymph, contributing to tissue fluid homeostasis and enabling immune responses by carrying lymphocytes and antigen‑presenting cells. They also play a key role in lipid absorption from the gut via lacteals.

Clinical relevance: Impaired lymphatic drainage can lead to lymphedema. Lymphatic vessels can serve as routes for cancer metastasis, and lymphangiogenesis (growth of new lymphatics) occurs in inflammation and tumor environments. Understanding lymfekarene is important for studies of edema, immunity, and cancer biology.