High endothelial venules

Definition

High endothelial venules are specialized blood vessels found in lymphoid tissues that facilitate the movement of lymphocytes from the bloodstream into the lymph node. They are characterized by their tall, cuboidal endothelial cells, unlike the flat cells of other blood vessels.

Related terms

Lymphocytes:

White blood cells that play a significant role in the body's immune response.

Lymph node: A small, bean-shaped structure that works as a filter for harmful substances and contains immune cells to fight infections.

Endothelial cells: Cells that line the interior surface of blood vessels and lymphatic vessels, forming a barrier between circulating blood or lymph in the lumen and the rest of the vessel wall