Question

what are blood vessels fmdsnatnrw​

Answer 1

Answer:

They're tough on the outside but they contain a smooth interior layer of epithelial cells that allows blood to flow easily.There are three kinds of blood vessels: arteries, veins, and capillaries.

Answer 2

Answer:

blood vessels:There are three kinds of blood vessels: arteries, veins, and capillaries. Each of these plays a very specific role in the circulation process. Arteries carry oxygenated blood away from the heart. They're tough on the outside but they contain a smooth interior layer of epithelial cells that allows blood to flow easily.