Define systolic and diastolic pressures and indicate which phase each represents.

• A. Systolic is arterial pressure during ventricular relaxation; diastolic is pressure during ventricular contraction.
• B. Systolic is venous pressure during contraction; diastolic is arterial pressure during relaxation.
• C. Systolic is mean arterial pressure; diastolic is pulse pressure.
• D. Systolic is arterial pressure during ventricular contraction; diastolic is pressure during ventricular relaxation.

Answer: (D)