Cardiovascular System - Transporting Fuel and Waste

Blood pressure is a measure of the force blood exerts against the wall of a vessel in units of millimeters of mercury (mmHg). Typical blood pressure is measured across the wall of an artery in the arm and is a reflection of high pressure after heart contraction (systole) and lower pressure with heart relaxation (diastole). Therefore, blood pressure is reported as systolic over diastolic and is normally around 120 over 80 mmHg.