blood pressure

(noun)

The pressure exerted by the blood against the walls of the arteries and veins; it varies during the heartbeat cycle and according to a person's age, health, and physical condition.

Related Terms

Examples of blood pressure in the following topics:

  • Extremes in Blood Pressure

    • Chronically elevated blood pressure is called hypertension, while chronically low blood pressure is called hypotension.
    • Hypertension or high blood pressure, sometimes called arterial hypertension, is a chronic medical condition in which the blood pressure in the arteries is elevated above 140/90 mmHg.
    • Even moderate elevation of arterial blood pressure is associated with a shortened life expectancy.
    • However, blood pressure is considered too low only if noticeable symptoms are present.
    • Graph showing changes in blood pressure during a single contraction-relaxation cycle of the heart.

  • Introduction to Blood Pressure

    • Blood pressure is a vital sign reflecting the pressure exerted on blood vessels when blood is forced out of the heart during contraction.
    • Blood pressure is the pressure that blood exerts on the wall of the blood vessels.
    • This is the main mechanism by which blood pressure operates.
    • Blood pressure is one of the principal vital signs.
    • A normal blood pressure should be around 120/80, with the systolic pressure expressed first.

  • Measuring Blood Pressure

    • Measurement of blood pressure includes systolic pressure during cardiac contraction and diastolic pressure during cardiac relaxation.
    • Blood pressure is the pressure blood exerts on the arterial walls.
    • A normal blood pressure is about 120 mmHg systolic over 80 mmHg diastolic.
    • Usually the blood pressure is read from the left arm, although blood pressures are also taken at other locations along the extremities.
    • Explain how blood pressure is measured and the ranges of blood pressure readings

  • Blood Pressure

    • Blood pressure is the pressure of blood against the blood vessel walls during the cardiac cycle; it is influenced by a variety of factors.
    • Blood pressure is the pressure of the fluid (blood) against the walls of the blood vessels.
    • The blood pressure of the systole phase and the diastole phase gives the two readings for blood pressure .
    • Stress triggers a decrease in the diameter of the blood vessels, consequently increasing blood pressure.
    • Blood pressure is related to the blood velocity in the arteries and arterioles.

  • Short-Term Neural Control

    • They send impulses to the cardiovascular center to regulate blood pressure.
    • Combined, these activities cause blood pressure to fall.
    • When blood pressure drops too low, the rate of baroreceptor firing decreases.
    • Combined, these activities cause blood pressure to rise.
    • Increased blood pressure results in increased rates of baroreceptor firing, whereas decreased blood pressure results in slower rates of fire, both initiating the homeostatic mechanism to restore blood pressure.

  • Cardiac Cycle

    • Systolic blood pressure is always higher than diastolic blood pressure, generally presented as a ratio in which systolic blood pressure is over diastolic blood pressure.
    • For example, 115/75 mmHg would indicated a systolic blood pressure of 115 mmHg and a diastolic blood pressure or 75 mmHG.
    • The normal range for blood pressure is between 90/60 mmHg and 120/80 mmHg.
    • Blood pressure is a regulated variable that is directly related to blood volume, based on cardiac output during the cardiac cycle.
    • Changes in contractility lead to pressure differences in the heart's chambers that drive the movement of blood.

  • Arterial Blood Pressure

    • The measurement of blood pressure without further specification usually refers to systemic arterial pressure measured at the upper arm.
    • The measurement of blood pressure without further specification usually refers to the systemic arterial pressure, defined as the pressure exerted by circulating blood upon the walls of blood vessels.
    • Pressure is typically measured with a blood pressure cuff (sphygmomanometer) wrapped around a person's upper arm, which measures the pressure in the brachial artery.
    • Blood pressure in the arteries is much higher than in the veins, in part due to receiving blood from the heart after contraction, but also due to their contractile capacity.
    • If systolic blood pressure is elevated (>140) with a normal diastolic blood pressure (<90), it is called "isolated systolic hypertension" and may present a health concern.

  • Introduction to Blood Flow, Pressure, and Resistance

    • If resistance increases, either pressure must increase to maintain flow, or flow rate must reduce to maintain pressure.
    • Blood pressure is the pressure that blood exerts on the wall of the blood vessels.
    • The pressure originates in the contraction of the heart, which forces blood out of the heart and into the blood vessels.
    • If flow is impaired through increased resistance then blood pressure must increase, so blood pressure is often used as a test for circulatory health.
    • Blood pressure can be modulated through altering cardiac activity, vasoconstriction, or vasodilation.

  • Artery Function

    • Arteries are high-pressure blood vessels that carry oxygenated blood away from the heart to all other tissues and organs.
    • Arteries are blood vessels that carry blood away from the heart under pressure.
    • In arteries, the tunica media, which contains smooth muscle cells and elastic tissue, is thicker than that of veins so it can modulate vessel caliber and thus control and maintain blood pressure.
    • Arterial pressure varies between the peak pressure during heart contraction, called the systolic pressure, and the minimum or diastolic pressure between contractions, when the heart expands and refills.
    • The pressure in the arterial system decreases steadily, highest in the aorta and lowest in the venous system, as blood approaches the heart after delivery of oxygen to tissues in the systemic circulation.

  • Gauge Pressure and Atmospheric Pressure

    • Pressure is often measured as gauge pressure, which is defined as the absolute pressure minus the atmospheric pressure.
    • Gauge pressure is a relative pressure measurement which measures pressure relative to atmospheric pressure and is defined as the absolute pressure minus the atmospheric pressure.
    • Most pressure measuring equipment give the pressure of a system in terms of gauge pressure as opposed to absolute pressure.
    • For example, tire pressure and blood pressure are gauge pressures by convention, while atmospheric pressures, deep vacuum pressures, and altimeter pressures must be absolute.
    • Explain the relationship among absolute pressure, gauge pressure, and atmospheric pressure