Questions: Which of the following is true about veins? Veins are considered blood reservoirs Venous contain large pressure gradients Veins have thick tunica media Venous valves form from the tunica media

The answer is the first one: Veins are considered blood reservoirs.

Explanation for each option:

1. Veins are considered blood reservoirs: This is correct. Veins can hold a large volume of blood and act as reservoirs due to their high capacitance.

2. Venous contain large pressure gradients: Incorrect. Veins have low pressure gradients compared to arteries, which is why they rely on valves and muscle contractions to aid blood flow back to the heart.

3. Veins have thick tunica media: Incorrect. Veins have a thinner tunica media compared to arteries, as they do not need to withstand high pressure.

4. Venous valves form from the tunica media: Incorrect. Venous valves are formed from the tunica intima, not the tunica media.

In summary, veins are indeed considered blood reservoirs due to their ability to hold a significant volume of blood.