Science Help!?

Question

Identify and describe the three types of blood vessels in the human body. Your answer should explain the following :
- the differences in their size (width) and structures
-the difference in their main functions and direction of flow
-if they usually carry oxygen - rich and/or oygen- poor blood

Ethan if u answer this u are definatly the smartest person one EARTH!

Answer 1

Veins, arteries, and capillaries.

You can do the rest.

PS: Why isn't this in Biology?