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30 Cards in this Set
- Front
- Back
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What events define the two heart sounds?
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Lub = mitral valve close
Dub = aortic and pulmonic valve close |
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Which organ extracts the most oxygen?
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Brain
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Artery or Vein:
Contains alpha-1 and beta-2 receptors |
Artery
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Artery or Vein:
Innervated by symphathetic nervous system |
Vein
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How is the perfusion of capillaries controlled? What branch of the nervous system is responsible for this?
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Dilation/Constriction of arterioles and pre-capillary sphincters
Regulated by symphathetic innervation of BVs and vasoactive metabolites |
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Which blood vessel types exhibit the largest area?
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Capillaries, then veins, then arteries
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Which blood vessel types receive the greatest blood volume?
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Veins, then arteries, then capillaries
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What is velocity? Equation?
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Velocity = rate of displacement of blood per unit time
v = Q/A where v = velocity Q = flow A = cross-sectional area |
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What is the relationship between area and velocity?
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Incerse relationship (v=Q/A), so
Small area-->High velocity |
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Where is the velocity of blood flow highest?
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v=Q/A
Thus in the vessels with the smallest area, which are: Aorta, then vena cava, then arteries |
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Where is the velocity of blood flow the lowest? Why would this be advantageous?
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Capillary bed (largest area)--allows for more time for exchange of nutrients
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What is the equation for calculating changes in pressure?
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deltaP=Q x R
Where Q = flow (mL/min) R = Resistance (mmHg/mL/min) |
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What is the equation for calculating resistance?
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R=deltaP/Q
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What is Total Peripheral Resistance?
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Resistance of entire systemic vasculature
AKA Systemic Vascular Resistance |
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Calculate the vascular resistance of the left kidney given:
Blood flow to the left kidney is measured at 500 mL/min Pressure in renal artery is 100 mmHg Pressure in the renal vein is 10 mmHg |
R = deltaP/Q
R = (100-10)/500 = 0.18 mmHg |
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What pressure drop would one measure to calculate the systemic vascular resistance?
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Mean Arterial Pressure - Mean Right Atrial Pressure
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What pressure drop would one measure to calculate the pulmonary vascular resistance?
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Mean Pulmonary ARTERIAL Pressure - Mean LEFT ATRIAL Pressure (can't get into pulmonary vein!)
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What is Poiseuille's equation for resistance?
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R = 8nl/pi*r^4
Where n = blood viscosity l = length of blood vessel r= vessel radius |
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Resistance increases as viscosity ________.
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Increases
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Resistance increases as length ________.
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Increases
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Resistance increases as radius __________.
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Decreases TO THE FOURTH POWER
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Is resistance in the body considered in series or in parallel? What equation would you use to calculate this?
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Resistance is in parallel (blood doesn't flow through each organ in series):
Parallel Resistance: Rtotal = 1/R1 + 1/R2 +1/R3 etc (Series resistance would be calculated by adding all resistances) |
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What is laminar flow? How is it interrupted?
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Laminar flow is a parabolic profile (flow is quickest in the middle) of velocity and is interrupted by irregularities in the vessel (causes turbulence)
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What are the Reynold's numbers for laminar/turbulent flow?
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Reynold's < 2000 = Laminar Flow
Reynold's > 2000 = turbulent flow |
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What is compliance in blood vessels proportional to?
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Compliance is proportional to deltaV/deltaP
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Arteries vs Veins:
Compliance |
Compliants in veins is high (can hold large volume of blood at low pressure because they expand)
Compliance of arteries is lower (hold a lower volume at a higher pressure) Older arteries are least compliant |
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Where does the largest drop in mean pressure occur in the cardiovascular system?
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At arteriolar level
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_______ pressure is pulsatile due to the cardiac cycle.
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Arterial
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Diastolic vs Systolic:
Pressure |
Diastolic: lowest pressure
Systolic: highest pressure |
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How is mean pressure calculated?
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Mean pressure = Diastolic pressure + 1/3*Pulse Pressure
Where Pulse Pressure = (systolic pressure - diastolic pressure) |
