Question : 51.The second heart sound produced by the a.opening of the AV : 1417116

 

51.The second heart sound is produced by the

a.opening of the AV valves

b.closing of the AV valves

c.opening of the semilunar valves

d.closing of the semilunar valves

e.blood rushing through the AV valves during diastole, creating a turbulent flow

52.The first heart sound

a.occurs when the AV valves open

b.occurs when the semilunar valves close

c.signals the onset of ventricular diastole

d.occurs when the AV valves close, and signals the onset of ventricular systole

e.occurs when the semilunar valves close, and signals the onset of ventricular diastole

53.The aortic valve opens

a.when ventricular pressure exceeds aortic pressure

b.just before ventricular systole begins

c.just after the isovolumetric relaxation phase

d.in response to the repolarization of contractile cells in the left ventricle

e.just before atrial diastole begins

54.During isovolumetric contraction,

a.rapid filling of the ventricles occurs

b.no blood enters or leaves the ventricles

c.the maximum volume of blood is ejected

d.the maximum rate of ejection occurs

e.Both a and b occur

55.The period lasting from closure of the AV valve to opening of the aortic valve is known as

a.isovolumetric ventricular contraction

b.isovolumetric ventricular relaxation

c.the rapid ejection phase

d.the rapid filling phase

e.ventricular diastole

56.A heart valve opens and closes due to

a.being pulled by the heart muscle

b.pressure differences on the valve's two sides

c.Na⁺ and K⁺ fluxes during ventricular depolarization

d.turbulent flow in the atria and ventricles

e.none of the above

57.Cardiac output

a.is the volume of blood pumped by each ventricle during each contraction or beat

b.is the volume of blood pumped by each ventricle per minute

c.equals heart rate divided by stroke volume

d.is both a and c

e.is both b and c

58.The dicrotic notch on the aortic pressure curve is due to

a.a disturbance set up by the aortic valve closing

b.a disturbance set up when the AV valves close

c.elastic recoil of the aorta during ventricular diastole

d.turbulent flow through a stenotic valve

e.atherosclerosis in the aorta

59.An insufficient AV valve

a.fails to open completely

b.is not connected to chordae tendineae

c.produces a gurgling diastolic murmur

d.allows blood to backflow into a ventricle during diastole

e.allows blood to leak into the pulmonary artery during right ventricular diastole

60.Atrial flutter is characterized by a ____ rhythm, as impulses pass from the AV node to the ventricles.