Lymph vessels

Lymph vessels or lymphatic vessels are thin-walled, valved structures that carry lymph, a fluid that is critical to the body's immune system. They form a major part of the lymphatic system, which also includes lymph nodes and lymphoid organs.

Structure

Lymph vessels are similar to blood vessels, but they carry lymph instead of blood. They are lined by endothelial cells, and have a thin layer of smooth muscle cells. The smallest lymph vessels are the lymph capillaries, which are found in nearly all tissues of the body. These capillaries merge to form larger lymph vessels.

Function

The primary function of the lymph vessels is to transport lymph from the tissues to the blood stream. This process is crucial for the body's immune response, as lymph contains white blood cells that help fight infection. The lymph vessels also play a role in the absorption of dietary fats from the digestive system.

Clinical significance

Diseases of the lymph vessels are generally referred to as lymphatic diseases. These include lymphedema, which is swelling caused by a blockage in the lymph vessels, and lymphangitis, which is inflammation of the lymph vessels. In addition, cancer can spread through the body by way of the lymph vessels, a process known as lymphatic metastasis.

See also

• Lymphatic system
• Lymph node
• Lymph
• Lymphatic diseases