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15 Cards in this Set
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What is the volume of blood flowing through a vessel, an organ, or the entire circulation in a given period (ml/min). If we consider the entire vascular system, blood flow is equivalent to cardiac output (CO), and under resting conditions, it is relatively constant. At any given moment, however, blood flow through individual body organs may vary widely and is intimately related to their immediate needs.
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Blood Flow
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What is the force per unit area exerted on a vessel wall by the contained blood, is expressed in millimeters of mercury (mm Hg). For example, a blood pressure of 120 mm Hg is equal to the pressure exerted by a column of mercury 120 mm high. Unless stated otherwise, the term blood pressure means systemic arterial blood pressure in the largest arteries near the heart. It is the pressure gradient—the differences in blood pressure within the vascular system—that provides the driving force that keeps blood moving, always from an area of higher pressure to an area of lower pressure, through the body.
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Blood Pressure
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What is is opposition to flow and is a measure of the amount of friction blood encounters as it passes through the vessels. Because most friction is encountered in the peripheral (systemic) circulation, well away from the heart, we generally use the term peripheral resistance. There are three important sources of resistance: blood viscosity, vessel length, and vessel diameter.
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Resistance
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What is the internal resistance to flow that exists in all fluids and is related to the thickness or “stickiness” of a fluid. The greater the viscosity, the less easily molecules slide past one another and the more difficult it is to get and keep the fluid moving. Because it contains formed elements and plasma proteins, blood is much more viscous than water; hence it flows more slowly under the same conditions. Blood viscosity is fairly constant, but infrequent conditions such as polycythemia (excessive numbers of red blood cells) can increase blood viscosity and, hence, resistance. On the other hand, if the red blood cell count is low, as in some anemias, blood is less viscous and peripheral resistance declines.
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Blood Viscosity
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What is this an example of "In a tube of a given size, the relative speed and position of fluid in the different regions of the tube’s cross section remain constant"
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Laminar Flow
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What is the difference between the systolic and diastolic pressures
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Pulse pressure
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What is the pressure that propels the blood to the tissues. Because diastole usually lasts longer than systole, the MAP is not simply the value halfway between systolic and diastolic pressures. Instead, it is roughly equal to the diastolic pressure plus one-third of the pulse pressure.
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mean arterial pressure (MAP
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What is the equation for figuring MAP
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MAP = Diastolic Pressure + (pulse pressure/3)
i.e. 80 + (40/3) = 93 mm Hg |
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How is pulse pressure figured
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Systolic - Diastolic
It is felt as a throbbing pulsation in an artery (a pulse) during systole, as the elastic arteries are expanded by the blood being forced into them by ventricular contraction. Increased stroke volume and faster blood ejection from the heart (a result of increased contractility) cause temporary increases in the pulse pressure. Pulse pressure is chronically increased by arteriosclerosis because the elastic arteries become less stretchy |
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What BP reading is the bottom line for hypertension
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140/80
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What BP reading for hypotension
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140/60
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What is a situation in which the heart fails to contract.
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Asystole
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What is inflammation of the endocardium, usually confined to the endocardium of the heart valves. Endocarditis often results from infection by bacteria that have entered the bloodstream but may result from fungal infection or an autoimmune response. Drug addicts may develop endocarditis by injecting themselves with contaminated needles.
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Endocarditis
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What is the leading cause of sudden death in young athletes, this condition, which is usually inherited, causes the cardiac muscle cells to enlarge, thickening the heart wall. The heart pumps strongly but doesn’t relax well during diastole when the heart is filling.
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Hypertrophic cardiomyopathy (HCM
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What is A heartbeat that is unusually strong, fast, or irregular so that the person becomes aware of it; may be caused by certain drugs, emotional pressures (“nervous heart”), or heart disorders.
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Heart palpitation
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