Nature of the Heart BeatThe fact th

Nature of the Heart BeatThe fact that the heart, completely removed from the body, will go on to beat for a time shows that its beat is «automatic», i.e. does not require nerve impulses.The beat is rhythmic: it is not jerky; the ventricles relax fully before the next contraction. This is explained by a special property of cardiac muscle tissue. The period of time during which the muscle is not responsive to a stimulus is called the refractory period. It is characteristic of the heart muscle to have a long refractory period. When the heart muscle is stimulated, it will contract but will not respond again to that stimulus (though it may respond to a stronger one) until it has relaxed. This rest period is occupied by the heart filling with blood, in preparation for the next beat. Even the heart forced to beat rapidly maintains a perfectly rhythmic beat; although the beats come closer together, there is always that little rest period in between.The heart is a pump, but a double pump; the volume expelled by the right ventricle is the same as that expelled by the left. When exercise is suddenly undertaken, the «venous return», i.e. the blood returned to the heart through the veins, is suddenly increased. For a few beats the right ventricle does put out more blood than the left, but soon the additional blood has passed through the lungs and is entering the left ventricle. From then on, both put out the same amount.

Результаты (английский) 1:

The Heart of Nature Beat

of The Fact That the heart, a completely removed from the old body, will of! Go on to beat for a time Shows That ITS beat is «automatic torque», ie The nerve does not the require The impulses.

The beat is rhythmic: it is not jerky; the ventricles relax fully before the next contraction. This is explained by a special property of cardiac muscle tissue. The period of time during which the muscle is not responsive to a stimulus is called the refractory period. It is characteristic of the heart muscle to have a long refractory period. When the heart muscle is stimulated, it will contract but will not respond again to that stimulus (though it may respond to a stronger one) until it has relaxed. This rest period is occupied by the heart filling with blood, in preparation for the next beat. Even the heart forced to beat rapidly maintains a perfectly rhythmic beat; although the beats come closer together, there is always that little rest period in between.

The heart is a pump, but a double pump; the volume expelled by the right ventricle is the same as that expelled by the left. When exercise is suddenly undertaken, the «venous return», ie the blood returned to the heart through the veins, is suddenly increased. For a few beats the right ventricle does put out more blood than the left, but soon the additional blood has passed through the lungs and is entering the left ventricle. From then on, both put out the same amount.

Результаты (английский) 2:

Nature of the Heart Beat

The fact that the heart, completely removed from the body, will go on to beat for a time shows that its beat is "automatic," i.e. does not require nerve impulses.

The beat is rhythmic: it is not jerky; the ventricles relax fully before the next contraction. This is explained by a special property of cardiac muscle muscle. The period of time during which the muscle is not responsive to a stimulus is called the refractory period. It is characteristic of the heart muscle to have a long refractory period. When the heart muscle is stimulated, it will contract but will not respond again to that stimulus (although it may respond to a stronger one) until it has relaxed. This rest period is occupied by the heart filling with blood, in preparation for the next beat. Even the heart forced to beat rapidly maintains a perfectly rhythmic beat; Although the beats come closer together, there is always that little rest period in between.

The heart is a pump, but a double pump; The volume expelled by the right ventricle is the same as that expelled by the left. When exercise is suddenly undertaken, the "venous return," i.e. the blood returned to the heart through the veins, is suddenly increased. For a few beats the right ventricle does put out more blood than the left, but soon the additional blood has passed through the lungs and is entering the left ventricle. From then on, both put out the same amount.

Результаты (английский) 3:

Nature of the Heart Beat
The fact that the heart，completely removed from the body，will go to beat for a time shows that its beat is“automatic”，i.e.does not require nerve impulses.
The beat is rhythmic:it is not jerky；the ventricles relatix fully before the next contraction. This is explained by a special property of cardiac muscle tissue. In this period of time, muscle does not respond to a stimulus, which is called the regeneration period. It is a feature of a long-term refractory period of heart disease. When heart rate is still a problem, it will be a contract, but it will not come back This is a time when the heart and blood mix for the next piece. Even if the heart is forced to maintain quickly in a perfect rhythmic beat; alter the beats come closer together, there is always that little rest period in between
The heart is a pump，but a double pump；the volume expelled by the right ventricle is the same as that expelled by the left. When exercise is totally undertaken, the "accidental return", i.e. the blood returned to the heart through the veins, is totally increased A feed beats the right venture does put out more blood than the left, but so on the additional blood has passed through the lungs and is entering the left venture Since then, both put out the same amount