lümfisoontesse

Lümfisoontesse refers to the lymphatic vessels, a crucial part of the lymphatic system. This intricate network runs throughout the body, parallel to the blood circulatory system, but instead of blood, it transports lymph. Lymph is a clear to yellowish fluid that originates from tissue fluid, also known as interstitial fluid. This fluid bathes the body's cells, delivering nutrients and removing waste products.

The lymphatic vessels are responsible for collecting excess interstitial fluid that doesn't return to the blood capillaries, along with proteins, fats, and other substances that are too large to enter the blood vessels directly. These vessels vary in size, from tiny lymphatic capillaries that begin in the tissues to larger lymphatic trunks and ducts that eventually drain into the bloodstream, typically near the heart.

The walls of lymphatic vessels are thin and permeable, allowing for the easy passage of fluid and substances from the surrounding tissues. Unlike blood vessels, lymphatic vessels possess valves that prevent the backflow of lymph, ensuring its unidirectional movement towards the thoracic duct or right lymphatic duct. The movement of lymph is propelled by the contraction of surrounding muscles, the pulsation of nearby arteries, and the smooth muscle in the walls of larger lymphatic vessels. This system plays a vital role in immune defense by transporting lymphocytes and filtering pathogens at lymph nodes, and it is also essential for fat absorption from the digestive system.