function of heart in human body
Answers
Answer:
Explanation:
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.
Blockage of any of these arteries can cause a heart attack, or damage to the muscle of the heart, Phillips said. A heart attack is distinct from cardiac arrest, which is a sudden loss of heart function that usually occurs as a result of electrical disturbances of the heart rhythm. A heart attack can lead to cardiac arrest, but the latter can also be caused by other problems, he said.
The heart contains electrical "pacemaker" cells, which cause it to contract — producing a heartbeat.
"Each cell has the ability to be the 'band leader' and [to] have everyone follow," Phillips said. In people with an irregular heartbeat, or atrial fibrillation, every cell tries to be the band leader, he said, which causes them to beat out of sync with one another.
A healthy heart contraction happens in five stages. In the first stage (early diastole), the heart is relaxed. Then the atrium contracts (atrial systole) to push blood into the ventricle. Next, the ventricles start contracting without changing volume. Then the ventricles continue contracting while empty. Finally, the ventricles stop contracting and relax. Then the cycle repeats.
Valves prevent backflow, keeping the blood flowing in one direction through the heart.
Arterial blood (red,O2 rich blood) flows from heart to each part of the body to provide oxygen and nutrients. Venus blood (blue, O2poor blood) returns from the body to the heart. The blood then travels through the lungs to exchange carbon dioxide for new oxygen. The heart is a pump which moves the blood. Hope it helps
The Heart is a pumping organ that receives blood from veins and pumps it into arteries.
Functions of Heart are:
1. To pump blood across the body.
There is only one function of Heart but this one function is the most important one in our whole body
Heart is a conical muscular double pump structure that brings about circulation of blood in the body. There are four chambers.
Deoxygenated blood from the whole body enters right auricle through a superior vena cava (from upper parts of the body), inferior vena cava (from middle and lower parts of the body) and coronary sinus (from the walls of the heart). Oxygenated blood is carried by pulmonary veins into left auricle from lungs. On being filled, the two auricles contract simultaneously and pass their bloods into ventricles, deoxygenated in right ventricle and oxygenated in left ventricle. The distended ventricles now undergo contraction or systole forcefully. Right ventricle passes blood to pulmonary arch which divides to form pulmonary arteries. Pulmonary arteries take the deoxygenated blood to lungs. Left ventricle passes blood to aorta that supplies oxygenated blood to all parts of the body.