Imusuonistot

Imusuonistot, often referred to as lymphatic capillaries, are the smallest vessels of the lymphatic system. They are microscopic, blind-ended tubes that permeate nearly all tissues of the body, with the notable exceptions of the central nervous system, bone marrow, avascular tissues like cartilage, and the cornea. Imusuonistot are characterized by their thin walls, composed of a single layer of endothelial cells. These cells overlap loosely, forming flap-like valves that open inward. This structure allows for the efficient uptake of interstitial fluid, as well as larger molecules like proteins and fats, which cannot easily re-enter blood capillaries.

The fluid that enters the imusuonistot is called lymph. Once inside, the lymph travels through progressively larger lymphatic vessels, eventually returning to the bloodstream. Imusuonistot play a crucial role in maintaining fluid balance within tissues by draining excess interstitial fluid. They are also vital for the immune system, as they transport immune cells and pathogens to lymph nodes, where immune responses can be initiated. Fats absorbed from the digestive tract are also transported via specialized lymphatic capillaries called lacteals, which are located in the villi of the small intestine. The network of imusuonistot is extensive, ensuring that nearly all tissues have access to this essential drainage and transport system.