A healthy heart with a normal cardiac output pumps about 5 to 6 liters of blood every minute when a person is resting. During exercise, your body may need three or four times your normal cardiac output, because your muscles need more oxygen when you exert yourself.
During exercise, your heart typically beats faster so that more blood gets out to your body. Your heart can also increase its stroke volume by pumping more forcefully or increasing the amount of blood that fills the left ventricle before it pumps. Generally speaking, your heart beats both faster and stronger to increase cardiac output during exercise. Sufficient cardiac output helps keep blood pressure at the levels needed to supply oxygen-rich blood to your brain and other vital organs.
Author: Healthwise Staff. Medical Review: Rakesh K. This information does not replace the advice of a doctor. Healthwise, Incorporated, disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. A muscle wall called the septum divides the two sides of the heart; the right side of the heart drives blood to the lungs while the left side pumps it to the rest of the body.
Blood from the body is collected in the right atrium and is pushed into the right ventricle with a small beat of the upper chamber of the heart. In the pulmonary circuit, deoxygenated blood leaves the right ventricle of the heart through the pulmonary artery and moves to the lungs. It then returns as oxygenated blood to the left atrium of the heart through the pulmonary vein. In the systemic circuit, oxygenated blood leaves the heart through the left ventricle to the aorta.
From there, the blood enters the arteries and capillaries, supplying oxygen to the body's tissues. Deoxygenated blood returns through the veins to the venae cavae, re-entering the heart's right atrium. The sino-atrial node is a special cell present in the right atrium. This node generates the first electrical impulse that coordinates the heart to beat in a regular fashion.
This node acts as a junction box between the atrium and the ventricle. As a kid, your resting pulse might range from 90 to beats per minute. As an adult, your pulse rate slows to an average of 72 beats per minute. The aorta, the largest artery in the body, is almost the diameter of a garden hose. Capillaries, on the other hand, are so small that it takes ten of them to equal the thickness of a human hair. Your body has about 5. This 5. In one day, the blood travels a total of 19, km 12, miles —that's four times the distance across the US from coast to coast.
The heart pumps about 1 million barrels of blood during an average lifetime—that's enough to fill more than 3 super tankers. Sound familiar?
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