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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

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

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

44.

Parasympathetic stimulation of heart is done at:

A.	Rest	B.	Sleeping
C.	Both (a) & (b)	D.	None of these

45.

Sympathetic stimulation of heart is done during:

A.	Stress	B.	Anger
C.	Excitement	D.	All of these

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

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

48.

Under which of these situations the rate of heartbeat is accelerated by noradrenaline:

A.	Stress	B.	Anger
C.	Excitement	D.	All of these

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

50.

During condition of fever the rate of our hearbeat will be:

A.	Increased	B.	Decreased
C.	First increased then decreased	D.	Unchanged