Assertion: Prolonged aerobic exercise training may also increase stroke volume, which frequently results in a lower (resting) heart rate.
Reason: Reduced heart rate prolongs ventricular diastole (filling), increasing end-diastolic volume, and ultimately allowing more blood to be ejected.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
3. If the assertion is true but the reason is false
4. If both the assertion and reason are false

Assertion: Veins are also called "capacitance vessels".
Reason: Most veins have valves to prevent backflow of blood.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion: Veins under skin appear blue in color.
Reason: All veins carry deoxygenated blood.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R): 

In the light of the above statements choose the correct answer from the options given below:

In the light of the above statements choose the correct answer from the options given below:

Assertion: Blood continuously flows into the arterioles and capillaries from the arteries even during the ventricular diastole.
Reason: The arteries remain pressurized throughout the cardiac cycle.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false

Assertion: Although rare, but runners and athletes can suffer heart failure if they stop vigorous exercise abruptly.
Reason: To reduce the risk athletes are encouraged to follow hard exercise with moderate activity such as walking.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion: Sudden emotional stress at the sight of blood may lead to syncope [fainting] in some individuals.
Reason: Due to sudden stress, simultaneous enhancement of parasympathetic nervous system (vagal) tone and withdrawal of sympathetic nervous system tone may occur.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion: The first and the second heart sounds are produced by the closure of AV and semilunar valves respectively.
Reason: The opening of the valves should not produce any sounds under normal physiological conditions.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false

Assertion: Coronary arteries are especially vulnerable to obstruction by atherosclerotic plaques or thrombus.
Reason: Coronary arteries supply oxygenated blood to the muscles of the heart itself.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.