mean arterial blood pressure

(noun)

A measure of blood pressure based on cardiac output and vascular resistance.

Related Terms

Examples of mean arterial blood pressure in the following topics:

  • Introduction to Blood Pressure

    • When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation.
    • Differences in mean blood pressure are responsible for blood flow from one location to another in the circulation.
    • The rate of mean blood flow depends on the resistance to flow presented by the blood vessels.
    • Mean blood pressure decreases as the circulating blood moves away from the heart through arteries, capillaries and veins due to viscous losses of energy.
    • Mean blood pressure drops over the whole circulation, although most of the fall occurs along the small arteries and arterioles.

  • Pressure in the Body

    • As the volume of blood within the circulatory system is confined to the veins, arteries, and capillaries there is a pressure within this closed system.
    • The mean arterial pressure (MAP) is the average pressure over a cardiac cycle and is determined by , where CO is the cardiac outputs, SVR is the systemic vascular resistance, and CVP is the central venous pressure (CVP).
    • In practice, the mean arterial pressure (MAP) can be approximated from easily obtainable blood pressure measurements in , where Psys is the measured systolic pressure and Pdias is the measured diastolic pressure.
    • The mean arterial pressure (MAP) is the average pressure over a cardiac cycle and is determined this equation, where CO is the cardiac outputs, SVR is the systemic vascular resistance, and CVP is the central venous pressure (CVP).
    • In practice, the mean arterial pressure (MAP) can be approximated from easily obtainable blood pressure measurements.

  • Venous Blood Pressure

    • Venous pressure is the vascular pressure in a vein or in the atria of the heart, and is much less than arterial pressure.
    • Blood pressure generally refers to the arterial pressure in the systemic circulation.
    • Portal venous pressure or the blood pressure in the portal vein.
    • The pressure within the circulatory circuit as a whole is denoted mean arterial pressure (MAP).
    • The resistance to flow generated by veins, due to their minimal ability to contract and reduce their diameter means that regulation of blood pressures by veins will be minimal in contrast to muscular vessels, primarily arterioles, that can actively contract, reduce diameter, and increase resistance and pressure.

  • Distribution of Blood

    • Humans have a closed cardiovascular system, meaning that blood never leaves the network of arteries, veins, and capillaries.
    • Humans have a closed cardiovascular system, meaning that the blood never leaves the network of arteries, veins, and capillaries.
    • On a larger level, vasoconstriction is one mechanism by which the body regulates and maintains mean arterial pressure.
    • Therefore, dilation of arterial blood vessels (mainly the arterioles) causes a decrease in blood pressure.
    • Oxygenated arterial blood (red) and deoxygenated venous blood (blue) are distributed around the body.

  • 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 mm Hg.
    • Hypertension is classified as either primary (essential) hypertension or secondary hypertension; about 90–95% of cases are categorized as "primary hypertension" which means high blood pressure with no obvious underlying medical cause.
    • Even moderate elevation of arterial blood pressure is associated with a shortened life expectancy.
    • Hypotension is a medical condition in which the blood pressure in the arteries is reduced below 100/60 mm Hg.

  • 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 which is defined as the pressure exerted by circulating blood upon the walls of blood vessels.
    • Pressure is typically measured with a blood pressure cuff or sphygmomanometer wrapped around a person's upper arm which measured 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.
    • At severely high pressures, mean arterial pressures 50% or more above average, a person can expect to live no more than a few years unless appropriately treated.

  • 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.
    • This blood is usually oxygenated, with the exception of that in the pulmonary artery, which carries deoxygenated blood to the lungs.
    • 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.
    • 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.

  • Great Vessels of the Heart

    • The human circulatory system is a double system, meaning there are two separate systems of blood flow: pulmonary circulation and systemic circulation.
    • The aorta is a highly elastic artery and is able to dilate and constrict in response to blood pressure and volume.
    • The difference in pressure between the aorta and right atrium accounts for blood flow in the circulation, as blood flows from areas of high pressure to areas of low pressure.
    • The aortic arch contains peripheral baroreceptors (pressure sensors) and chemoreceptors (chemical sensors) that relay information concerning blood pressure, blood pH, and carbon dioxide levels to the medulla oblongata of the brain.
    • These are the only arteries that carry deoxygenated blood, and are considered arteries because they carry blood away from the heart.

  • Hypertension

    • 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.
    • The repercussions of chronically elevated blood pressure included widespread damage to the circulatory system, arterial disease, cardiac failure and even neurological impairments
    • Hypertension is classified as either primary (essential) hypertension or secondary hypertension; about 90–95% of cases are categorized as "primary hypertension" which means high blood pressure with no obvious underlying medical cause.
    • Even moderate elevation of arterial blood pressure is associated with a shortened life expectancy.
    • Persistant high blood pressure can affect many areas of the body.

  • The Aorta and Its Branches

    • The aorta is an elastic artery, meaning it is able to distend.
    • This stretching generates the potential energy that helps maintain blood pressure during diastole, as during this time the aorta contracts passively.
    • These arteries provide blood to the heart muscle, their blockage is the cause myocardial infarctions or heart attacks.
    • These arteries provide blood to both arms and the head.
    • Within the abdomen, the descending aorta branches into the two common iliac arteries that provide blood to the pelvis and, eventually, the legs.