Systolic pressure measures what?

• A. The pressure in the arteries when the heart ventricles contract
• B. The pressure in the arteries when the heart ventricles relax between contractions
• C. The pressure in the veins when the heart is at rest
• D. The pressure inside the heart chambers during filling

Answer: (A)

Systolic pressure is the pressure in the arteries during ventricular contraction when the heart is actively pumping blood into the arterial system. This peak pressure occurs as the ventricles squeeze blood out, making it the highest arterial pressure in the cardiac cycle. It’s the top number in a blood pressure reading (for example, the 120 in 120/80). The other descriptions relate to different moments: the pressure when the ventricles relax between beats is diastolic pressure; pressure in the veins isn’t what systolic measures; and pressure inside the heart chambers during filling is a different, filling-phase value. So the statement about arteries during ventricular contraction best captures what systolic pressure measures.