The human heart contracts from the

The human heart contracts from the first moment of life until the last one. The contractions of the heart pump the blood through the arteries to all the parts of the body. Scientists have determined that the total weight of the blood pumped by the heart daily is about ten tons.
The rate of heart contractions is regulated by two groups of nerve fibers. It varies in different persons and at different age.
Physiologists have determined that in the adult the heart makes from 60 to 72 beats per minute. In children the rate of heartbeat is much higher. Research work of many scientists has helped to determine that the rate of heartbeat increases depending on different emotions.
Each beat of the heart is followed by a period of rest for the cardiac muscle. Each wave of contraction and a period of rest following it compose a cardiac cycle.
Research work has given physiologists the possibility to find out that the heart muscle works or contracts about one third of the time of the person’s life. The period of rest is shorter during greater physical exertion and longer when the body is at rest.
Each cardiac cycle consists of three phases: physiologists have called the first phase of short contraction of both atria—the atrial systole. They have called the second phase of a more prolonged contraction of both ventricles—the ventricular systole. The period of rest of the cardiac muscle is called the diastole.
The left ventricle discharges out the blood received by the left atrium from the pulmonary circulation through the aorta to the systemic circulation.
The blood received from the systemic circulation by the right atrium is discharged out of the right ventricle to the lungs through the pulmonary arteries.
Prolonged research work of many physiologists has given the possibility to estimate the role of the ventricles which serve as the main pump. The atria act as receiving chambers. The contraction of the atria which sends the final portion of the blood into the ventricle is considerably less.

Результаты (английский) 2:

The human heart contracts from the first moment of life until the last one. The contractions of the heart pump the blood through the arteries to all the parts of the body. That have a determined Scientists the total weight of the blood Pumped by the heart daily, is about ten tons.
Of The rate The heart of Contractions is regulated by nerve to two two The groups of the fibers. It varies in Different It persons and AT Different age.
Physiologists have a determined That the adult in the heart Makes from 60 to 72 beats per minute. In children the rate of heartbeat is much higher. Work of MANY Research, Scientists has Helped to the Determine That the heartbeat of the rate The Increases depending on Different emotions.
Each beat of the heart is Followed by a period of the rest for the cardiac muscle. Wave of contraction Each and a period of the rest the following IT The compose a cardiac cycle.
Research, work has Given physiologists to the Possibility That the find out the heart muscle works or about one's Contracts THIRD, of the time of the person's life:. Period of the rest of The is shorter DURING Physical exertion of is greater and longer a the when the body is AT the rest.
Each cardiac cycle Consists of a three Phases: physiologists have Called the first phase of short contraction of Both atria-the atrial systole. They have called the second phase of a more prolonged contraction of both ventricles-the ventricular systole. Of The period of the rest of the cardiac muscle is Called the diastole.
Of The left ventricle discharges the out the blood the Received by the left atrium from the pulmonary circulation through the aorta to the systemic circulation.
Of The blood the Received from the systemic circulation by the right atrium is is discharged of the right out ventricle to the lungs through the pulmonary arteries.
Prolonged research work of physiologists has MANY Given the Possibility to Estimate the role of the ventricles the which the serve as with the main pump. The atria act as receiving chambers. The contraction of the atria which sends the final portion of the blood into the ventricle is considerably less.

Результаты (английский) 3:

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