Which of the following causes increase in conduction velocity of impulse through heart -
Ans. is 'c' i.e., Sympathetic stimulation o Effects of sympathetic stimulation are :Heart positive chronotropic (| heart ratef ii) Positive ionotropic (| contractility), iii) Positive dromotropic (| conduction velocity), iv) Positive bathmotropic (increased automaticity), v) Decreased refractory period in all cardiac cells.Vasoconstriction | total peripheral resistance (due to arteriolar constriction), |venous capacitance (due to venoconstriction)Increased stroke volume, cardiac output and BP.o Effects of parasympathetic stimulation areNegative chronotropic (decreased heart rate) : - Vagal stimulation cause decrease in slope (flattening) of prepotential (pacemaker potential) and therefore the time taken to reach the threshold levelis increased - Heart rate is decreased.Negative dromotropic (decreased conduction).Increased refractory period of all type of cardiac cells.
Vagal stimulation
Parasympathetic stimulation
Sympathetic stimulation
All of the above
Heart: Rhythmical Excitation of the Heart