A Level Biology Practice Exam

Small blood vessels that distribute blood from arteries to capillaries are called what?

1. Arterioles

2. Venules

3. Capillaries

4. Veins

The correct answer is: Arterioles

The correct term for small blood vessels that distribute blood from arteries to capillaries is arterioles. Arterioles are branches of arteries and play a crucial role in regulating blood flow into the capillary networks. They are smaller in diameter than arteries and possess smooth muscle in their walls, which allows them to constrict and dilate to control blood pressure and flow to different tissues as needed. Capillaries, on the other hand, are the tiny vessels where the exchange of gases, nutrients, and waste occurs between blood and tissues. Venules collect blood from capillaries and carry it to veins, which transport blood back to the heart. Veins are larger vessels that return deoxygenated blood to the heart after it has passed through the capillaries. Thus, it is the arterioles that specifically serve the function of distributing blood from arteries to the capillaries.