Dictionary ,Human heart,Kidney,liver

Human heart function

The heart circulates blood through two pathways: the pulmonary circuit and the systemic circuit.

In the pulmonary circuit, deoxygenated blood leaves the right ventricle of the heart via the pulmonary artery and travels to the lungs, then returns as oxygenated blood to the left atrium of the heart via the pulmonary vein.

In the systemic circuit, oxygenated blood leaves the body via the left ventricle to the aorta, and from there enters the arteries and capillaries where it supplies the body's tissues with oxygen. Deoxygenated blood returns via veins to the venae cavae, re-entering the heart's right atrium.

Of course, the heart is also a muscle, so it needs a fresh supply of oxygen and nutrients, too, Phillips said.

"After the blood leaves the heart through the aortic valve, two sets of arteries bring oxygenated blood to feed the heart muscle," he said. The left main coronary artery, on one side of the aorta, branches into the left anterior descending artery and the left circumflex artery. The right coronary artery branches out on the right side of the aorta.

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Kidney

One of a pair of organs located in the right and left side of the abdomen. The kidneys remove waste products from the blood and produce urine. As blood flows through the kidneys, the kidneys filter waste products, chemicals, and unneeded water from the blood. Urine collects in the middle of each kidney, in an area called the renal pelvis. It then drains from the kidney through a long tube, the ureter, to the bladder, where it is stored until elimination. The kidneys also make substances that help control blood pressure and regulate the formation of red blood cells.

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liver

The liver has multiple functions. It makes many of the chemicals required by the body to function normally, it breaks down and detoxifies substances in the body, and it also acts as a storage unit.

Hepatocytes (hepar=liver + cyte=cell) are responsible for making many of the proteins (protein synthesis) in the body that are required for many functions, including blood clotting factors, and albumin, required to maintain fluid within the circulation system. The liver is also responsible for manufacturing cholesterol and triglycerides. Carbohydrates are also produced in the liver and the organ is responsible for turning glucose into glycogen that can be stored both in the liver and in the muscle cells. The liver also makes bile that helps with food digestion.

The liver plays an important role in detoxifying the body by converting ammonia, a byproduct of metabolism in the body, into urea that is excreted in the urine by the kidneys. The liver also breaks down medications anddrugs, including alcohol, and is responsible for breaking down insulin and other hormones in the body

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