Final answer:
Veins are blood reservoirs in the body, holding around 60% of the blood at rest due to their high capacitance, which allows them to store a significant volume of blood at low pressure.
Step-by-step explanation:
At rest, about 60% of blood is held within the veins, which function as the body's blood reservoirs.
Veins have a high capacitance, meaning they can expand significantly to store more blood at low pressure compared to arteries. This feature allows them to serve as the primary blood reservoirs in the body, containing a greater portion of the total blood volume at any given time. Veins have larger lumens and thinner walls, which greatly contributes to their ability to hold a high volume of blood.
This distinct characteristic highlights the importance of veins in the circulatory system beyond merely returning blood to the heart, as they also play a key role in maintaining blood volume and pressure balance within the body.holding approximately 60% of the blood at rest.Systemic veins function as the body's blood reservoirs, holding approximately 60% of the blood at rest. Veins have high capacitance, allowing them to expand and store a large volume of blood at low pressure. Their large lumens and thin walls make them more distensible than arteries, making them capacitance vessels.