What are the three major types of blood vessels?

The three major types of blood vessels in the circulatory system are arteries, veins, and capillaries. Each type has a distinct role in the transport of blood throughout the body.

Arteries are responsible for carrying oxygenated blood away from the heart to the tissues, except for the pulmonary arteries, which carry deoxygenated blood to the lungs. They have thick, muscular walls that allow them to withstand and regulate the high pressure of blood being pumped from the heart.

Veins, on the other hand, transport deoxygenated blood back to the heart, except for the pulmonary veins, which carry oxygenated blood from the lungs. Veins have thinner walls than arteries and often have valves that prevent backflow, ensuring that blood moves in one direction despite the lower pressure in the venous system.

Capillaries are the smallest blood vessels and serve as the site of nutrient, gas, and waste exchange between blood and surrounding tissues. Their thin walls facilitate the diffusion of substances, making them crucial for maintaining the body’s physiology.

This distinction among blood vessels is foundational in understanding the circulatory system's function, as each type plays a critical role in overall cardiovascular health. The inclusion of lymphatics, nerves, or ducts in other options reflects an