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Human Body Study

Arteries

The vessels that carry blood away from the heart.

The closed-loop circulation A four-chambered heart at the centre, with a pulmonary loop to the lungs above and a systemic loop to a body capillary bed below; red vessels carry oxygen-rich blood, blue vessels oxygen-poor. A separate inset shows blood at a vessel cross-section. Each label links to the article for that part. Blood RA LA RV LV Heart Arteries Capillaries Veins The closed-loop circulation — schematic, not to scale.

Structure

Section titled “Structure”

Thick, muscular, elastic walls — built to withstand and smooth out the high pressure of each heartbeat. They branch into progressively smaller vessels, ending in tiny arterioles.

What they do

Section titled “What they do”
  • Carry blood away from the heart — oxygen-rich blood to the body, oxygen-poor blood to the lungs.
  • Arterioles adjust their diameter to control how much blood reaches each region and to help set overall blood pressure.

Key idea

Section titled “Key idea”

Arteries are pressure vessels; their elasticity stores energy with each beat and releases it to keep blood flowing between beats. Stiffening of the arteries is a hallmark of aging and disease.