THE MAIN ARTERIES AND VEINS

The main artery in your body is the aorta. It carries bright red (oxygenated) blood to the tissues of the body. The ascending aorta emerges upward from your left ventricle. It makes a U-turn in the upper part of the chest and descends to become the abdominal aorta. Large branches lead from your aorta to your head, trunk, arms, and legs. The main arteries supplying your head are the carotid arteries. Your arms receive their blood supply through the axillary arteries, and your legs receive their blood supply through the femoral arteries. These main branches divide into smaller ones as they get farther away from.

Your pulmonary artery carries blood from your heart to your lungs. It arises from your right ventricle and transports dark bluish red (deoxygenate to the lungs.

The main veins in your body are the superior and inferior venae cavae They empty into the right atrium. The superior vena cava receives blood from your head through the veins, and from your arms through the axillary veins. The inferior vena cava receives blood from several veins in the abdomen and from your legs through the femoral veins. As with the arteries, the veins branch into smaller ones as they get farther away from heart. In this case, though, blood flows from the small vessels into the ones and finally into the heart.

Your pulmonary vein carries newly oxygenated blood from your lungs to the left atrium of your heart.

At any given time, 9 percent blood is traveling to and from the lungs in your pulmonary vessels and 7 percent is in your heart. By greatest volume of blood (84 percent is in the vessels that travel to and from the rest of your body. These vessels are called the systemic arteries and veins (the systemic circulation). With systemic circulation, 64 percent blood of the blood in the body is in the veins, 13 percent is in the arteries, and 7 percent is in the tiny branching arteriole and capillaries.

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Cardio & Blood