Fill in the blanks. - BP is the ______ per unit area exerted by the blood on the walls of the blood vessels within a closed system. Pressure is measured in ______ (the units). Systole: ____________ phase of the cardiac cycle Diastole: ____________ phase of the cardiac cycle - Normal resting BP is characterized by a systolic BP of less than _______ and a diastolic BP of less than _______.