What is a venule?

A venule is defined as the smallest type of vein in the circulatory system. After blood passes through the capillaries, where exchange of gases and nutrients occurs, it collects into venules. These venules serve to transport deoxygenated blood from the capillaries back to larger veins, eventually leading to the heart. Their structure is characterized by a thin layer of muscular tissue and a wider lumen compared to capillaries, which enables them to collect blood from the capillary bed efficiently.

The correct recognition of a venule as the smallest type of vein emphasizes its essential role in the venous return pathway, illustrating how blood is gradually collected and conveyed back to the heart for reoxygenation. Knowing this also provides insight into the differences between venules, veins, and capillaries, aiding in the understanding of the entire circulatory system.