What does the artieries do?

carry blood away from the heart to other parts of the body.

ANSWER:

Arteries usually carry oxygenated blood from heart to all the parts of the body whereas a coronary artery carries oxygenated blood and supplies it to the heart muscle-myocardium (for its functioning!) and that's where usually angina results as a result of artery thickening.

Also the pulmonary artery is the only artery to carry de-oxygenated blood from the heart to the lungs for purification!!