Explanation

Arteries are blood vessels that carry oxygen-rich blood away from the heart to the body. The heart pumps blood into the aorta, the largest artery. From there, blood flows through smaller arteries to reach all body tissues.

Arteries have thick, muscular walls that can handle high pressure from the heart pumping. These strong walls help push blood throughout the body. The pulmonary artery is the only artery that carries deoxygenated blood, taking it to the lungs.

Veins carry blood back to the heart, opposite of arteries. Capillaries are tiny vessels where oxygen and nutrients leave blood to enter tissues. Venules are small veins that collect blood from capillaries before it enters larger veins.