An artery is a blood vessel that carries blood away from your heart to the rest of your body. Think of arteries as highways for blood, with your heart as the central station pumping blood outward through these sturdy tubes. The largest artery, the aorta, is about as wide as a garden hose and branches into smaller and smaller arteries that reach every part of you, from your brain to your toes.

Arteries have thick, muscular walls because they handle blood under high pressure as your heart pumps. You can feel this pressure as your pulse when you press gently on your wrist or neck. That rhythmic throb is blood surging through your arteries with each heartbeat.

Most arteries carry oxygen-rich blood (which looks bright red), delivering oxygen and nutrients that your cells need to work. The main exceptions are the pulmonary arteries, which carry oxygen-poor blood from your heart to your lungs to pick up fresh oxygen.

The word also appears in everyday speech. When someone talks about a “main artery” of a city, they mean a major road that carries traffic to different neighborhoods, just like your arteries carry blood throughout your body. People often talk about keeping their arteries healthy, because clogged or damaged arteries make it harder for the heart to do its essential work of keeping you going.