A metarteriole is a vessel that __________.

• A. returns interstitial fluid to the circulation
• B. is intermediate between the arteriole and the capillary bed
• C. drains the capillary bed
• D. is intermediate between a capillary and a venule

Answer: (B)

Verified step by step guidance

1. Begin by understanding the structure and function of a metarteriole. A metarteriole is a type of blood vessel that serves as a transitional vessel between an arteriole and a capillary bed.
2. Recognize that metarterioles play a crucial role in microcirculation, which is the circulation of blood in the smallest blood vessels, including capillaries, arterioles, and venules.
3. Identify the primary function of metarterioles. They regulate blood flow into the capillary beds by acting as a bypass channel, allowing blood to flow directly from arterioles to venules when capillaries are closed.
4. Understand that metarterioles are not involved in returning interstitial fluid to the circulation. This function is typically performed by lymphatic vessels.
5. Conclude that the correct description of a metarteriole is that it is intermediate between the arteriole and the capillary bed, facilitating the transition and regulation of blood flow in microcirculation.