Question

which of the following blood vessel carries oxygenated blood?
A. Pulmonary artery
B. Pulmonary vein
C. Aorta
D. Both B and C​

Answer 1

A blood vessel is a tube that carries blood. Oxygen rich blood leaves the left side of the heart and enters the aorta. The aorta branches into arteries, which eventually branch into smaller arterioles. Arterioles carry blood and oxygen into the smallest blood vessels, the capillaries.

Capillaries are so small they can only be seen under a microscope. The walls of the capillaries are permeable to oxygen and carbon dioxide. Oxygen moves from the capillary toward the cells of the tissues and organs. Carbon dioxide moves from the cells and into the capillaries.