systolic blood pressure

(noun)

The highest pressure within the bloodstream, occurring during each heartbeat because of the systole.

Related Terms

Examples of systolic blood pressure in the following topics:

  • 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.
    • Low blood pressure, or hypotension, is indicated when the systolic number is persistently below 90 mmHg.
    • A blood pressure cuff and associated monitor used for determining systolic and diastolic pressures within an artery.

  • Cardiac Cycle

    • Throughout the cardiac cycle, the arterial blood pressure increases during the phases of active ventricular contraction and decreases during ventricular filling and atrial systole.
    • Thus, there are two types of measurable blood pressure: systolic during contraction and diastolic during relaxation.
    • 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.

  • 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.
    • Systolic pressure is thus the pressure that your heart emits when blood is forced out of the heart and diastolic pressure is the pressure exerted when the heart is relaxed.
    • During each heartbeat, blood pressure varies between a maximum (systolic) and a minimum (diastolic) pressure.
    • A normal blood pressure should be around 120/80, with the systolic pressure expressed first.

  • 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.
    • A person's blood pressure is usually expressed in terms of the systolic pressure over diastolic pressure and is measured in millimeters of mercury (mmHg), for example 140/90.
    • In the past, most attention was paid to diastolic pressure, but now we know that both high systolic pressure and high pulse pressure (the numerical difference between systolic and diastolic pressures) are also risk factors for disease.
    • 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.

  • Hypertension

    • Hypertension is elevated blood pressure, clinically defined as at or greater than 140/90 (systolic/diastolic) mm/Hg.
    • Hypertension (HTN) or high blood pressure, sometimes called arterial hypertension, is a chronic medical condition in which the blood pressure in the arteries is elevated.
    • Blood pressure involves two measurements, systolic and diastolic, which depend on whether the heart muscle is contracting (systole) or relaxed between beats (diastole).
    • Normal blood pressure at rest is within the range of 100-140mmHg systolic (top reading) and 60-90mmHg diastolic (bottom reading).
    • Persistant high blood pressure can affect many areas of the body.

  • Extremes in Blood Pressure

    • Chronically elevated blood pressure is called hypertension, while chronically low blood pressure is called hypotension.
    • In healthy adults, physiological blood pressure should fall between the range of 100-140 mmHg systolic and 60-90 mmHg diastolic.
    • 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.

  • Operation of Semilunar Valves

    • During ventricular systole, pressure rises in the left ventricle.
    • When the pressure in the left ventricle exceeds the pressure in the aorta, the aortic valve opens, and blood flows from the left ventricle into the aorta.
    • When ventricular systole ends, pressure in the left ventricle drops rapidly, and the aortic pressure forces the aortic valve to close.
    • Similar to the aortic valve, the pulmonary valve opens in ventricular systole, when the pressure in the right ventricle exceeds the pressure in the pulmonary artery.
    • When ventricular systole ends, pressure in the right ventricle drops rapidly, and the pressure in the pulmonary artery forces the pulmonary valve to close.

  • 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.

  • Chambers of the Heart

    • The atria undergo atrial systole, a brief contraction of the atria that ejects blood from the atria through the valves and into the ventricles.
    • There are no atrial inlet valves to interrupt blood flow during atrial systole.
    • The venous blood entering the heart has a very low pressure compared to arterial blood, and valves would require venous blood pressure to build up over a long period of time to enter the atria.
    • The physiologic load on the ventricles, which pump blood throughout the body and lungs, is much greater than the pressure generated by the atria to fill the ventricles.
    • During ventricular systole, the ventricles contract, pumping blood through the semi-lunar valves into systemic circulation.

  • Operation of Atrioventricular Valves

    • The atrioventricular (AV) valves separate the atria from the ventricles on each side of the heart and prevent backflow of blood from the ventricles into the atria during systole.
    • The subvalvular apparatus has no effect on the opening and closing of the valves, which is caused entirely by the pressure gradient of blood across the valve as blood flows from high pressure to low pressure areas.
    • Atrial systole (contraction) increases the pressure in the atria, while ventricular diastole (relaxation) decreases the pressure in the ventricle, causing pressure-induced flow of blood across the valve.
    • The ring contracts at the end of atrial systole due to the contraction of the left atrium around it, which aids in bringing the leaflets together to provide firm closure during ventricular systole.
    • Blood passes through the tricuspid valve the same as it does through the bicuspid valve, based on a pressure gradient from high pressure to low pressure during systole and diastole.