The major blood vessels in the human body are the aortae, ARTERIES, and aortas. The aortae are the two main ARTERIES that carry oxygenated blood away from the heart to the rest of the body. The ARTERIES are the vessels that branch off from the aortae and carry oxygenated blood to the organs and tissues. The aortas are the two main veins that carry deoxygenated blood back to the heart. All three of these vessels are essential for the circulation of blood throughout the body.