MCQs on Cardiovascular System - Physiology

# The first heart sound is produced by the :
A. Closure of the aortic and pulmonary valves
B. Opening of the aortic and pulmonary valves
C. Closure of the mitral and tricuspid valves
D. Opening of the mitral and tricuspid valves

# Parasympathetic stimulation of heart causes:
A. SA node decreases firing
B. Increased AV node excitability
C. Decreased ventricular contraction
D. Tachycardia

# Normally, the rate of the heart beat in a human is determined by:
A. Bundle of His
B. all cardiac muscles
C. the SA node
D. the cervical ganglion

# The ventricular repolarisation in ECG is best seen in:
A. "P" wave
B. "Q" wave
C. "R" wave
D. "T" wave

# Stroke output of each ventricle in normal adult is :
A. 30 ml
B. 130 ml
C. 70 ml
D. 5 liters

# Cardiac output is a measure of :
A. Peripheral resistance * tissue fluid
B. Peripheral resistance * cardiac rate
C. Blood pressure * Cardiac rate
D. Heart rate * Stroke volume

# Cardiac output is not affected by :
A. Heart rate
B. Peripheral resistance
C. Systolic blod pressure
D. Venous return

# The largest function of the total peripheral resistance is due to:
A. Venules
B. Arterioles
C. Capillaries
D. Precapillary sphincters

# All the heart valves are open during which stage of cardiac cycle?
A. Systolic ejection
B. Isovolumetric relaxation
C. Isovolumetric contraction
D. None of the above

# Minimum blood Pressure is in:
A. Aorta
B. Arteries
C. Capillaries
D. Venules
# Starling's law of the heart
A. Does not operate in the failing heart
B. Does not operate during exercise
C. Explains the increase in cardiac output that occurs when venous return is increased
D. Explains the increase in cardiac output when the sympathetic nerves supplying the heart are stimulated

# Which of the followings is true ?
A. Starling's law of heart states that increase in force of contraction is directly related to cardiac output
B. Starling's law of heart states that the force of ventricular contraction is directly related to the end diastolic volume
C. Both A and B
D. None of the above

# Peripheral resistance is maximum in:
A. Aorta
B. Artery
C. Arteriole
D. Vein

# Stimulatuion of baroreceptor leads to :
A. Increased blood pressure, Increased heart rate
B. Decreased BP, decreased heart rate
C. Increased BP, decreased heart rate
D. Decreased BP, Increased heart rate

# Increased functional demand on the heart produces increased size of the myocardium by:
A. Hyperplasia
B. Hypertrophy
C. Fatty infiltration
D. Increased amounts of fibrous connective tissue

# Cardiac index is related to :
A. Cardiac output and body weight
B. Cardiac output and body surface area
C. Cardiac output and work of the heart
D. Stroke volume and pulse rate

# Absolute refractory period in heart :
A. Lasts till cardiac contraction
B. Longer than refractory period in skeletal muscle
C. A phase of cardiac cycle in which heart cannot be stimulated by any amount of stimulus
D. Corresponds with duration of action potential
E. All of the above

# Closure of the aortic valve occurs before the following event:
A. Isovolumetric contraction
B. Isovolumetric relaxation
C. Prediastole
D. Presystole

# Conduction velocity is least in:
A. AV node
B. SA Node
C. Purkinje fibers
D. Budele of His

# Fastest conducting tissue in human heart:
A. AV node
B. SA node
C. Bundle of His
D. Purkinje fibers

# Under resting condition, the cardiac output is ____ L/min:
A. 2.5
B. 4.25
C. 5.25
D. 9.5

# Coronary blood flow is usually predominantly controlled by :
A. Auto regulation
B. Hormones
C. Parasympathetic impulses
D. Sympathetic impulse

# Cardiac output in L/min divided by heart rate equals:
A. Cardiac efficiency
B. Cardiac index
C. Mean Stroke volume
D. Mean arterial pressure

# Cardiac cycle duration in man is:
A. 0.4 sec
B. 0.8 sec
C. 1.2 sec
D. 1.6 sec

# First heart sound occurs during the period of:
A. Isotonic relaxation
B. Isovolumetric relaxation
C. Isovolumetric contraction
D. Isotonic contraction