Which blood vessels are responsible for carrying impure blood back to the heart?

Veins are responsible for carrying impure blood back to the heart. They are part of the circulatory system and function to transport deoxygenated blood – which has delivered oxygen to the body's tissues and picked up carbon dioxide and other waste products – back to the heart for reoxygenation. This is a critical step in maintaining the body's overall function and health, as it allows for the removal of waste and the replenishment of oxygen supply.

Arteries, in contrast, carry oxygenated blood away from the heart to the body, while capillaries are the tiny blood vessels where the exchange of gases, nutrients, and wastes occurs between blood and tissues. The aorta is the largest artery in the body, carrying oxygen-rich blood directly from the heart to systemic circulation. Thus, the role of veins in returning deoxygenated blood to the heart is distinct and essential for the circulatory process.