Assertion (A): SA-node is called pacemaker.
Reason (R): SA node generates least number of action potentials to initiate rhythmic contraction of heart.
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false.
Subtopic: Â Human Heart: Gross Anatomy |Â Rhythmic Excitation of Human Heart: Part 1 |Â Rhythmic Excitation of Human Heart: Part 2 |
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Assertion (A): The cardiac output of a normal human is greater than an athelete.
Reason (R): The stroke volume of a normal men is greater than an athelete.
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false.
Subtopic: Â Human Heart: Cardiac Cycle |
 89%
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Assertion (A): The neural signals through the sympathetic nerves increase the heart-beat, thereby decreasing the cardiac output.
Reason (R): Adrenalin secretion drastically decrease cardiac output.
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false.
Subtopic: Â Regulation of Cardiac Activity |
 84%
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Assertion (A): All vertebrate have hepatic portal system.
Reason (R) All animals have hepatic portal system.
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false.
Subtopic: Â Human Heart: Double Circulation |
 53%
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Assertion (A): In joint diastole, all the four chambers of heart are in relaxed state.
Reason (R): The atrio-ventricular valves are open and the semilunar valves are closed at this stage.
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false.
Subtopic: Â Human Heart: Cardiac Cycle |
 63%
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Assertion (A): A symptom of acute chest pain is called 'Angina pectroris'.
Reason (R): In this condition heart do not pump blood effectively to meet body needs.
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false.
Subtopic: Â Atherosclerosis, Hypertension & Ventricular Fibrillation |Â DISORDERS OF CIRCULATORY SYSTEM |
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Assertion (A): Lymph is called the 'middle man' of body.
Reason (R): Exchange of nutrients, gases and other materials between blood and the cells always occur through this fluid.
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false.
Subtopic: Â Lymph |
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Assertion (A): If an individual stands immobile for a long time, it leads to accumulation of fluids in the leg tissues and swelling in feet.
Reason (R): Contraction of muscles compresses the veins to move the blood inside them.
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false.
Subtopic: Â Blood: General Description & RBC: Part 1 |Â Blood: General Description & RBC: Part 2 |Â Human Heart: Double Circulation |
 65%
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Assertion (A): The cardiac impulse which originates from SA node in human heart cannot spread directly from atria to ventricles.
Reason (R): In human heart there is no continuity between cardiac muscle fibres of atria and those of ventricles except AV bundles.
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false.
Subtopic: Â Human Heart: Cardiac Cycle |Â Rhythmic Excitation of Human Heart: Part 1 |Â Rhythmic Excitation of Human Heart: Part 2 |
 51%
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