arterial blood pressure

Examples of arterial 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.
  • Hypotension is a medical condition in which the blood pressure in the arteries is reduced below 100/60 mmHg.
  • However, blood pressure is considered too low only if noticeable symptoms are present.

• 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.
  • All levels of arterial pressure put mechanical stress on the arterial walls.

• 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.

• Measuring Blood Pressure

  • Blood pressure is the pressure blood exerts on the arterial walls.
  • Usually the blood pressure is read from the left arm, although blood pressures are also taken at other locations along the extremities.
  • These pressures, called segmental blood pressures, are used to evaluate blockage or arterial occlusion in a limb (for example, the ankle brachial pressure index).The difference between the systolic and diastolic pressure is called the pulse pressure.
  • A blood pressure cuff and associated monitor used for determining systolic and diastolic pressures within an artery.
  • Explain how blood pressure is measured and the ranges of blood pressure readings

• Blood Pressure

  • Blood pressure is the pressure of the fluid (blood) against the walls of the blood vessels.
  • In the arteries, the hydrostatic pressure near the heart is very high.
  • The systolic pressure is defined as the peak pressure in the arteries during the cardiac cycle; the diastolic pressure is the lowest pressure at the resting phase of the cardiac cycle.
  • During systole, when new blood is entering the arteries, the artery walls stretch to accommodate the increase of pressure of the extra blood.
  • Blood pressure is related to the blood velocity in the arteries and arterioles.

• 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.
  • Blood pressure is one of the principal vital signs.
  • 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.

• Great Vessels of the Heart

  • 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.
  • This part of the aorta is vulnerable to bursting and hemorrhage (aneurysm) from persistently high blood pressure.
  • These are the only arteries that carry deoxygenated blood, and are considered arteries because they carry blood away from the heart.

• Arteries, Veins, and Capillaries

  • Arteries take blood away from the heart.
  • The iliac artery takes blood to the lower limbs.
  • The movement of materials at the site of capillaries is regulated by vasoconstriction, narrowing of the blood vessels, and vasodilation, widening of the blood vessels; this is important in the overall regulation of blood pressure.
  • The arteries have thicker smooth muscle and connective tissue than the veins to accommodate the higher pressure and speed of freshly-pumped blood.
  • The veins are thinner walled as the pressure and rate of flow are much lower.

• Elastic Arteries

  • Elastic arteries include the largest arteries in the body, those closest to the heart, and give rise to the smaller muscular arteries.
  • Arterial elasticity gives rise to the Windkessel effect, which through passive contraction after expansion helps to maintain a relatively constant pressure in the arteries despite the pulsating nature of the blood flow from the heart.
  • Due to position as the first part of the systemic circulatory system closest to the heart and the resultant high pressures it will experience, the aorta is perhaps the most elastic artery, featuring an incredibly thick tunica media rich in elastic filaments.
  • When the left ventricle contracts to force blood into the aorta, the aorta expands.
  • This stretching generates the potential energy that will help maintain blood pressure during diastole, when the aorta contracts passively.

• Operation of Semilunar Valves

  • The semilunar valves allow blood to be pumped into the major arteries, but prevent backflow of blood from the arteries into the ventricles.
  • These valves allow blood to be pumped into the arteries, but prevent backflow of blood from the arteries into the ventricles.
  • When the atrioventricular valves shut, the semilunar valves open, forcing blood into the aorta and pulmonary artery.
  • 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 right ventricle drops rapidly, and the pressure in the pulmonary artery forces the pulmonary valve to close.