What type of vessels are responsible for returning blood to the heart?

Veins are the type of vessels responsible for returning blood to the heart. They play a crucial role in the circulatory system by collecting deoxygenated blood from various body parts and transporting it back to the heart, specifically into the right atrium.

Unlike arteries, which carry oxygen-rich blood away from the heart, veins work under lower pressure and are equipped with one-way valves that prevent blood from flowing backward. Their structure allows them to expand and accommodate varying volumes of blood, facilitating the return journey.

While capillaries are small vessels that connect arteries and veins, and venules are small veins that collect blood from capillaries, the primary function of returning blood to the heart is specifically fulfilled by veins. Thus, the correct answer highlights the function of veins in the circulatory process.