Lümfijuhtmed

Lümfijuhtmed, also known as lymphatic vessels, are a crucial part of the lymphatic system. They form a network throughout the body that collects and transports lymph, a fluid containing white blood cells, from tissues back into the bloodstream. This system plays a vital role in immunity and fluid balance.

The lymphatic vessels begin as small, blind-ended capillaries in the tissues. These capillaries merge to form larger vessels, eventually leading to two main lymphatic ducts: the thoracic duct and the right lymphatic duct. The thoracic duct, the largest lymphatic vessel, drains lymph from most of the body, while the right lymphatic duct drains lymph from the right side of the head and neck, the right arm, and the right side of the thorax.

Unlike the circulatory system, the lymphatic system does not have a central pump like the heart. Instead, the flow of lymph is driven by muscle contractions, breathing movements, and the pulsing of nearby arteries. Lymphatic vessels contain one-way valves that prevent the backflow of lymph, ensuring unidirectional movement towards the heart.

Along their course, lymphatic vessels are interrupted by lymph nodes, which act as filters for the lymph. Within the lymph nodes, immune cells like lymphocytes and macrophages identify and destroy foreign substances, such as bacteria and viruses, that are present in the lymph. This filtering process is essential for preventing the spread of infection throughout the body.

Disruptions to lymphatic vessels can lead to lymphedema, a condition characterized by swelling due to the accumulation of lymph fluid in the tissues. This can be caused by congenital abnormalities, surgery, radiation therapy, or infection.