ANATOMY

Detailed explanation-1: -Systolic blood pressure is measured when the heart ventricles contract. Diastolic blood pressure is measured when the heart ventricles relax. A systolic pressure of 115 millimeters of mercury is considered normal, as is a diastolic pressure of 70. Commonly, this pressure would be stated as 115 over 70.

Detailed explanation-2: -The relaxation phase is called ventricular diastole, and during this period pressure in the aorta and pulmonary arteries falls to lower values called diastolic pressure.

Detailed explanation-3: -During ventricular diastole, venous blood enters the left atrium, and when blood pressure within the left atrium exceeds blood pressure in the left ventricle, the mitral valve opens and passive filling of the ventricle occurs.

Detailed explanation-4: -The cardiac cycle is essentially split into two phases, systole (the contraction phase) and diastole (the relaxation phase).