CSS :: Circulatory System Physiology
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41. |
The heart rate in man is increased by: |
A. |
Sympathetic nerve fibres by releasing sympathin at free verve endings |
B. |
By parasympathetic nerve fibres by releasing acetylcholine at their free nerve endings |
C. |
Both of these nerve fibres |
D. |
None of these fibres |
Answer: Option A
Explanation:
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42. |
Sympathetic nerve fibres increase the rate of heartbeat by releasing which of these at their free endings: |
A. |
Adrenaline |
B. |
Noradrenaline |
C. |
Acetylcholine |
D. |
None of these |
Answer: Option B
Explanation:
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43. |
Parasympathetic nerve fibres decrease the rate of heartbeat by releasing which of these at their free endings: |
A. |
Acetylcholine |
B. |
Adrenaline |
C. |
Noradrenaline |
D. |
None of these |
Answer: Option A
Explanation:
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44. |
Parasympathetic stimulation of heart is done at: |
A. |
Rest |
B. |
Sleeping |
C. |
Both (a) & (b) |
D. |
None of these |
Answer: Option C
Explanation:
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45. |
Sympathetic stimulation of heart is done during: |
A. |
Stress |
B. |
Anger |
C. |
Excitement |
D. |
All of these |
Answer: Option D
Explanation:
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46. |
Acetylcholine retards the rate of heart beating by: |
A. |
Decreasing the rate of initiation of heart beat in SA-Node |
B. |
Decreasing the excitability of fibres of internodal pathway |
C. |
Both (a) & (b) |
D. |
None of these |
Answer: Option C
Explanation:
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47. |
Noradrenaline accelerates the beating of heart by: |
A. |
Increasing the discharge rate of SA-node |
B. |
Increasing the rate of conduction of excitability in various parts of the heart |
C. |
Increasing the force with which the cardiac muscles contract |
D. |
By bringing all these changes |
Answer: Option D
Explanation:
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48. |
Under which of these situations the rate of heartbeat is accelerated by noradrenaline: |
A. |
Stress |
B. |
Anger |
C. |
Excitement |
D. |
All of these |
Answer: Option D
Explanation:
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49. |
Under which of these conditions, the heart rate is retarded by liberating acetylcholine: |
A. |
Rest |
B. |
Sleep |
C. |
Both (a) & (b) |
D. |
None of these |
Answer: Option D
Explanation:
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50. |
During condition of fever the rate of our hearbeat will be: |
A. |
Increased |
B. |
Decreased |
C. |
First increased then decreased |
D. |
Unchanged |
Answer: Option A
Explanation:
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