Subcapsular sinus

Subcapsular sinus is a part of the lymph node that plays a crucial role in the immune system. It is the space between the lymph node capsule and the cortex which allows the lymph to flow into the lymph node.

Anatomy

The subcapsular sinus, also known as the marginal sinus, is a channel that encircles the lymph node. It is lined by a layer of endothelial cells and is continuous with the trabecular sinuses. The sinus is filled with lymph, which enters through the afferent lymphatic vessels and exits through the efferent lymphatic vessels.

Function

The primary function of the subcapsular sinus is to act as a filtration system. It filters the lymph to remove foreign particles, such as bacteria and viruses, before the lymph enters the lymph node. This is a crucial step in the body's immune response. The sinus also serves as a pathway for lymphocytes to enter the lymph node.

Clinical significance

In certain diseases, such as lymphoma and metastatic cancer, the subcapsular sinus can be involved. In these cases, the sinus may be filled with cancer cells, which can impede the normal flow of lymph and disrupt the function of the lymph node.

See also

• Lymphatic system
• Lymph node
• Immune system