Question

What will be the number of heartbeats per minute, if the stroke volume of the heart increases while the total volume of blood remains the same?
A) Remains constant
B) Decreases
C) Increases
D) Become erratic

Answer 1

Hint: Heartbeats is the number of times our heartbeats in each minute. Stroke volume and heartbeat are correlated with the term cardiac output. We can get to know about the number of heartbeats by knowing the cardiac output.

Complete answer:
For our body to function properly, the heart should pump blood at a sufficient rate to maintain adequate amounts of oxygen and nutrients to the brain as well as to the other vital organs.
Stroke volume is defined as the amount of blood your heart pumps in a beat each time. The term stroke volume can be applied to two ventricles of the heart. For each ventricle, the stroke volume is generally equal that is approximately 70 mL in a healthy 70- kg man. It is an important determinant of cardiac output.

Heartbeat is an important sign of health in the human body. It helps in measuring the number of heartbeats a number of times per minute. It is not only the speed of the heart that is important but it is the rhythm of the heartbeat. In a healthy person, the heartbeats approx 72 times in a minute.
The body has the ability to alter the stroke volume as well as the heartbeat of the body and thereby the cardiac output.

Cardiac output is the volume of the blood pumped out by each ventricle per minute.
Cardiac Output is the product of stroke volume and heartbeats.
Since according to the question the volume remains constant and stroke volume increases, the number of heartbeats should decrease to satisfy the above formula.

So, the correct answer is option B, Decreases.

Note: Cardiac output can be increased by doing vigorous exercises regularly. It is dependent on the heart as well as the circulatory system such as veins and arteries. Carbon dioxide is the product of heart rate (HR) by stroke volume (SV), the volume of blood ejected by the heart in each beat.