Lymphatic capillary

Lymphatic capillary (also known as lymph capillaries or lymphatic vessels) are tiny, thin-walled microvessels located in the tissues of the body that absorb lymph and transport it to the larger lymphatic vessels. They form an important part of the lymphatic system, which contributes to the body's immune system by defending against infection and disease.

Structure

Lymphatic capillaries are slightly larger in diameter than blood capillaries, and have a unique structure that enables them to serve their function effectively. They are composed of a single layer of endothelial cells and have a unique one-way structure that allows interstitial fluid to enter the capillary, but not to exit. This is achieved through the presence of overlapping endothelial cells which act like one-way valves.

Function

The primary function of lymphatic capillaries is to absorb and transport lymph, a clear fluid containing white blood cells, throughout the body. This fluid is collected from the interstitial space, which is the space between cells. The lymph is then transported to larger lymphatic vessels, and eventually to the lymph nodes, where it is filtered and any potential harmful substances, such as bacteria or viruses, are destroyed.

Lymphatic capillaries also play a crucial role in the absorption of dietary fats in the small intestine. Specialized lymphatic capillaries known as lacteals are responsible for this function.

Clinical significance

Damage or blockage of lymphatic capillaries can lead to a condition known as lymphedema, which is characterized by swelling in the affected area due to the buildup of lymph. This condition can be caused by a variety of factors, including infection, cancer, and surgical removal of lymph nodes.