What is the largest blood vessel in the human body?
The largest blood vessel is called the aorta. It is an artery which contains muscular walls capable of pumping blood containing oxygen away from the heart and directs its flow toward various tissues. The smooth muscle of the arteries pushes the blood through the circulatory system and is the pulse that can be measured at various pulse points in the body.
The left ventricle of the heart pumps out oxygenated blood which flows through the aortic valve into the aorta and this blood vessel provides the necessary force to pump the blood to all parts of the body. The aorta has branches that bring blood to the brain as well as to all organs and tissues of the body.
As the aorta branches off, it forms smaller arteries, then arterioles, then finally capillaries. These are capable of allowing diffusion between body cells and the circulating blood. Nutrients, oxygen and water can cross from the blood into the cells and wastes like carbon dioxide can pass from the cells back to the circulating blood to be transported to organs of excretion.
I have included a link with a diagram of the blood flowing through the heart and into the aorta, and another of the aorta in detail.
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