What structure collects blood from the capillaries and drains it into veins?

The structure that collects blood from the capillaries and drains it into veins is known as a venule. Although "venule" itself is not one of the answer choices provided, the closest correct option in this context is the vein.

Veins are responsible for carrying deoxygenated blood back to the heart after the capillaries have exchanged oxygen, nutrients, and waste products with the tissues. After blood moves through the capillary beds, it enters smaller venous vessels, which progressively merge into larger veins. This function is critical in maintaining proper circulation and ensuring that waste products are effectively removed from the body's tissues.

Understanding this flow is essential for comprehending the circulatory system; blood flows from arteries to arterioles, then into capillaries for nutrient and gas exchange, and finally is collected into venules that combine into veins leading back to the heart.