mean arterial pressure

(noun)

The average arterial pressure during a single cardiac cycle.

Related Terms

Examples of mean arterial pressure in the following topics:

  • 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.
    • Generalized vasoconstriction usually results in an increase in systemic blood pressure, but it may also occur in specific tissues, causing a localized reduction in blood flow.
    • Therefore, dilation of arterial blood vessels (mainly the arterioles) causes a decrease in blood pressure.

  • Arterial Blood Pressure

    • The measurement of blood pressure without further specification usually refers to systemic arterial pressure measured at the upper arm.
    • 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.
    • All levels of arterial pressure put mechanical stress on the arterial walls.
    • Even moderate elevation of arterial pressure leads to shortened life expectancy.
    • At mean arterial pressures 50% or more above average, a person can expect to live no more than a few years unless appropriately treated.

  • Venous Blood Pressure

    • Venous pressure is the vascular pressure in a vein or the atria of the heart, and is much lower than arterial pressure.
    • Blood pressure generally refers to the arterial pressure in the systemic circulation.
    • It is much lower than arterial pressure, with common values of 5 mmHg in the right atrium and 8 mmHg in the left atrium.
    • The pressure within the circulatory circuit as a whole is 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 pressure by veins is minimal in contrast to that of muscular vessels, primarily arterioles.

  • Introduction to Blood Pressure

    • 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.
    • Differences in mean blood pressure are responsible for blood flow from one location to another in circulation.
    • The rate of mean blood flow depends on the resistance to flow presented by the blood vessels.
    • Mean blood pressure decreases as circulating blood moves away from the heart through arteries, capillaries, and veins due to viscous loss of energy.
    • Mean blood pressure decreases during circulation, although most of this decrease occurs along the small arteries and arterioles.

  • Extremes in Blood Pressure

    • 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.
    • 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.
    • Hypertension is a major risk factor for stroke, myocardial infarction (heart attacks), heart failure, aneurysms of the arteries (e.g. aortic aneurysm), peripheral arterial disease and a cause of chronic kidney disease.
    • 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 mmHg.

  • The Aorta and Its Branches

    • The aorta is the largest artery in the systemic circulatory system.
    • 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, since during this time the aorta contracts passively.
    • The arch of the aorta has three branches: the brachiocephalic artery, which itself divides into right common carotid artery and the right subclavian artery, the left common carotid artery, and the left subclavian artery.
    • These arteries provide blood to both arms and the head.

  • 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.
    • This pressure variation within the artery produces the observable pulse that reflects heart activity.

  • 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.
    • Hypertension is a major risk factor for stroke, myocardial infarction (heart attacks), heart failure, aneurysms of the arteries (e.g. aortic aneurysm), peripheral arterial disease and is a cause of chronic kidney disease.
    • Even moderate elevation of arterial blood pressure is associated with a shortened life expectancy.

  • Checking Circulation

    • The rate of the pulse is observed and measured by tactile or visual means on the outside of an artery and recorded as beats per minute (BPM).
    • Systolic pressure is peak pressure in the arteries, which occurs near the end of the cardiac cycle when the ventricles are contracting.
    • Diastolic pressure is minimum pressure in the arteries, which occurs near the beginning of the cardiac cycle when the ventricles are filled with blood.
    • Hypertension refers to abnormally high arterial pressure, as opposed to hypotension, when it is abnormally low.
    • The cuff pressure is further released until no sound can be heard (fifth Korotkoff sound), at the diastolic arterial pressure.

  • 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.