What is the average number of times the heart beats per minute? Define the terms "systolic" and "diastolic" blood pressure. What are the typical pressures of the blood under each of these conditions? In what part of the circulatory system is blood pressure the greatest? Where can the swings between systolic and diastolic blood pressure be felt?
The heart rate or number of times per unit time that the heart beats is around 70 times per minute in humans. The pressure of the blood in the heart during heart muscle contraction, called systolic pressure, is around 120 mm Hg. The pressure of the blood in the heart during heart muscle relaxation, called diastolic pressure, is around 80 mm Hg. Overall blood pressure is greatest in the heart and arteries and falls off rapidly in the arterioles reaching its lowest point in the veins just before they reach the heart. The great swing between the systolic and diastolic pressures is most notable in the heart and main arteries, falls off in the arterioles, and is non-existent in the capillaries and veins being replaced by a constant rate of flow.
