A. 0.7 seconds
B. 0.3 seconds
C. 0.7 seconds
D. 0.4 seconds
Related Mcqs:
- 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 - First heart sound occurs during the period of________________?
A. Isotonic relaxation
B. Isovolumetric relaxation
C. Isovolumetric contraction
D. Isotonic contraction - The absolute refractory period of an action potential is due to _______________?
A. Insufficient neurotransmitter
B. Depletion of intracellular Na+
C. Inactivation of Na+ k+ ATPase
D. Voltage inactivation of the Na+ channel - Primary dentition period is______________?
A. From birth to 11 years
B. From 6 months to 11 years
C. From 6 months to 6 years
D. From 6 years to 11 years - 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 - 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 output in L/min divided by heart rate equals_______________?
A. Cardiac efficiency
B. Cardiac index
C. Mean stroke volume
D. Mean arterial pressure - The effects of Adrenaline on heart are all except__________________?
A. Increases heart rate
B. Decreases myocardial irritability
C. Increases force of contraction
D. Increases oxygen uptake by heart - Parasympathetic stimulation of heart causes______________?
A. SA node decreases firing
B. Increased AV node excitability
C. Decreased ventricular contraction
D. Tachycardia - Effect on force of contraction of heart is_____________?
A. Chronotropic effect
B. Dromotropic effect
C. Bathmotropic
D. Ionotropic effect
