What blood vessel type conveys blood from the systemic circulation back to the heart?

Veins are the blood vessel type that conveys blood from the systemic circulation back to the heart. They carry deoxygenated blood, except for the pulmonary veins, which transport oxygenated blood from the lungs to the heart. Veins have thinner walls and larger lumens than arteries, allowing them to accommodate varying volumes of blood. Valves within veins help prevent the backflow of blood as it moves toward the heart.