The smallest veins are called venules.
Venules play a vital role in the circulatory system, functioning as the crucial link between capillaries and larger veins. Here's a breakdown:
- Connection to Capillaries: Venules receive blood directly from capillaries, the smallest blood vessels in the body.
- Exchange of Substances: Like capillaries, venules participate in the exchange of oxygen, nutrients, and waste products between the blood and surrounding tissues. This exchange is facilitated by post-capillary sphincters located between the capillaries and venules.
- Function: Venules collect blood from the capillaries and transport it to the larger veins for return to the heart.
In summary, venules are the smallest type of vein and are responsible for collecting blood from the capillaries.
