The lymphatic system ensures the movement of lymph through the lymphatic vessels and promotes the outflow of excess fluid from the tissues.
Many tissues have tiny lymphatic capillaries that end blindly. The intercellular fluid penetrates into them, which forms the lymph. Lymphatic capillaries merge into larger lymphatic vessels that permeate all organs and tissues. On the inner walls of the lymphatic vessels, valves are located, thanks to which the lymph moves in one direction (the valves prevent the lymph from flowing back).
Lymph nodes are located along the lymphatic vessels. The nodes act as filters that trap microorganisms. They contain a large number of lymphocytes, which are actively involved in the body’s immune responses.
There are especially many lymph nodes in the armpit, popliteal and elbow folds, in the chest and abdominal cavities, on the neck.
All lymphatic vessels are combined into ducts that flow into the large veins of the systemic circulation.
Due to this, fluid returns to the bloodstream from the tissues.