Question: what are the three main blood vessels in your body?
Answer: The Three Major Types of Blood Vessels: Arteries, Veins, and Capillaries. ... 
Oxygenated Blood Flows Away from the Heart Through Arteries. ... 
Veins Carry Blood Back Toward the Heart. ... 
Exchange of Gases, Nutrients, and Waste Between Blood and Tissue Occurs in the Capillaries.