What are arteries and arterioles?

Your body has a super high-speed delivery system that moves warm, oxygen-rich blood from your heart to every tiny corner of your body.

Think of your arteries as big, stretchy rubber hoses. They are the main roads that carry blood away from your heart. Because the heart pumps blood out with a strong whoosh, these tubes need to be tough and bouncy. Imagine squeezing a wet sponge; the water squirts out fast. Arteries handle that squishy, fast-moving flow without bursting. They are thick and strong, built to handle the heart's powerful beat.

As the big arteries branch out, they get smaller and smaller, turning into arterioles. These are like the little gates or turnstiles at a busy playground. They control exactly how much blood gets through to the tiniest capillaries. If your muscles need more oxygen because you are running, the arterioles widen to let more blood in. If you are resting, they narrow to slow the flow down. They act like adjustable nozzles on a garden hose, letting your body decide exactly where the precious fuel should go.