Aoic valve closure corresponds to the beginning of:September 2011
Ans. C: Isovolumetric relaxationCardiac DiastoleIt is the period of time when the hea relaxes after contraction in preparation for refilling with circulating blood.During ventricular diastole, the pressure in the (left and right) ventricles drops from the peak that it reaches in systole.When the pressure in the left ventricle drops to below the pressure in the left atrium, the mitral valve opens, and the left ventricle fills with blood that was accumulating in the left atrium.The isovolumic relaxation time (IV) is the interval from the aoic component of the second hea sound, that is, closure of the aoic valve, to onset of filling by opening of the mitral valve.Likewise, when the pressure in the right ventricle drops below that in the right atrium, the tricuspid valve opens, and the right ventricle fills with blood that was accumulating in the right atrium.During diastole the pressure within the right ventricle is lower than that in aoa, allowing blood to circulate in the hea itself the coronary aeries.
Systole
Parasystole
Isovolumetric relaxation
Isovolumetric contraction