Which type of blood vessel carries oxygenated blood away from the heart?

Oxygenated blood is carried away from the heart primarily by arteries. The key factor that differentiates arteries from other types of blood vessels is their role in transporting blood that is rich in oxygen, especially visible in the systemic circulation, where the left ventricle pumps oxygenated blood into the aorta and subsequently to various parts of the body through a network of arteries.

The structural characteristics of arteries, including their thicker walls and muscular layers, enable them to withstand and maintain the high pressure from the heart's pumping action. This structural feature is crucial for their function in delivering oxygen and nutrients to tissues throughout the body effectively.

In contrast, veins serve to return deoxygenated blood back to the heart, capillaries are the sites of gas exchange where oxygen is delivered to tissues and carbon dioxide is collected, and venules are small vessels that collect blood from capillaries and transport it to veins. Each of these vessel types has distinct roles, but in terms of carrying oxygenated blood away from the heart, arteries are the correct answer.