Pulse vs. Blood Pressure
Difference Between Pulse And Blood Pressure
Pulse, the rhythmic expansion and contraction of an artery. Each time the heart beats, a wave of muscular contraction, called the pulse wave, starts at the aorta and quickly spreads through all the arteries, forcing the blood through them. The pulse wave travels about 20 to 30 feet (6–9 meters) a second, becoming weaker as it travels farther from the heart.
The pulse may be felt at many places in the body where an artery passes near the skin. The radial artery in the wrist is the one that is most often used for examining the pulse, although arteries in the neck and ankle are also sometimes used for this purpose.
The rate and strength of the pulse are affected by many factors, including age, sex, and the presence of disease. In an infant the pulse rate ranges from 110 to 140 beats per minute. In a child it becomes slightly slower and shallower. In adolescents the pulse becomes strong and ranges from 80 to 90 beats a minute. In adults the rate ranges from 70 to 72 beats per minute in men and from 78 to 82 beats per minute in women. In older persons the pulse rate slows to about 60 beats per minute. Exercise normally speeds up the pulse rate. From a resting rate of 75, the rate may be raised to 100 by light exercise; to 130 by moderate exercise; and to as high as 200 by very heavy exercise.
Blood Pressure, the pressure exerted by blood against the walls of the arteries. Each time the heart contracts, propelling blood through the circulatory system, pressure rises, and each time the heart relaxes, blood pressure falls.
Blood pressure is usually assessed using a sphygmomanometer, an instrument consisting of an inflatable rubber cuff connected to a pressure gauge. The measurement is taken by placing the cuff around the patient’s upper arm, pumping enough air into the cuff to cut off the limb’s circulation, and then gradually permitting the air to escape. Listening through a stethoscope placed on the arm, a doctor notes the pressure indicated on the gauge at the moment that he or she first hears the sound of blood rushing back into the arm. In this way the physician determines the least amount of pressure needed to prevent blood from entering the limb. Called the systolic pressure, it indicates the force exerted against the arteries when the heart contracts. As the heart relaxes, the lowest level to which the pressure falls is known as the diastolic pressure. This is determined by noting the pressure on the gauge at the instant that the physician can no longer hear the sound of blood rushing through the arteries or at the time the intensity of the sound suddenly diminishes. In persons 18 years or older, the normal systolic pressure is below 120 mm (5 inches) of mercury and the normal diastolic pressure is under 80 mm (3 inches).