Lümfikapillaaride

Lümfikapillaarid are tiny, dead-end vessels that form a crucial part of the lymphatic system. They are microscopic tubes that are found throughout the body's tissues, interspersed among blood capillaries. Unlike blood capillaries which form a closed circuit, lümfikapillaarid have blind ends, meaning they don't connect to form a continuous loop. Their primary function is to collect excess interstitial fluid, also known as lymph, along with leaked proteins, cellular debris, and other waste products from the body's tissues.

The walls of lümfikapillaarid are exceptionally thin, composed of a single layer of endothelial cells. These cells are arranged loosely, with overlapping edges that act like one-way valves. When the pressure of the interstitial fluid outside the capillary is higher than the pressure inside, these flaps open, allowing fluid to enter. Once inside, the pressure pushes the flaps closed, preventing the lymph from leaking back out. This unique structure makes lümfikapillaarid highly permeable and efficient at absorbing substances from the surrounding environment.

After collecting lymph, lümfikapillaarid gradually merge to form larger lymphatic vessels. These vessels then transport the lymph towards the heart, eventually returning it to the bloodstream. The lymphatic system, with its lümfikapillaarid, plays a vital role in maintaining fluid balance within the body, removing waste, and transporting fats absorbed from the digestive system. They are essential for immune function, as they also carry immune cells and filter pathogens.