Lymphangion

Lymphangion

A lymphangion is a functional unit of a lymphatic vessel that is located between two semilunar valves. It is a segment of the lymphatic system that plays a crucial role in the transport of lymph from the peripheral tissues to the central venous system.

Diagram of a lymph vessel showing lymphangions

Structure

Lymphangions are composed of a layer of endothelial cells that line the interior surface, surrounded by a layer of smooth muscle cells. The smooth muscle layer is responsible for the rhythmic contractions that propel lymph through the lymphatic system. These contractions are known as lymphatic pumping.

Function

The primary function of a lymphangion is to facilitate the movement of lymph through the lymphatic system. The semilunar valves within the lymphangion prevent the backflow of lymph, ensuring unidirectional flow towards the thoracic duct or the right lymphatic duct.

Lymphangions contract in response to various stimuli, including mechanical stretch, which occurs as lymph fills the vessel, and chemical signals from the surrounding tissue. This contraction is an intrinsic property of the lymphangion and is crucial for maintaining lymphatic circulation.

Clinical significance

Dysfunction of lymphangions can lead to conditions such as lymphedema, where the impaired transport of lymph results in swelling of the affected tissues. Understanding the mechanics and regulation of lymphangion contraction is important for developing treatments for such conditions.

Related pages

• Lymphatic system
• Lymph node
• Lymphatic vessel
• Lymph
• Lymphedema