Download - Hemodynamics _27_
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1. According to theFick principle,blood flow isequal to?
O2 consumption/([O2]B - [O2]A)2. According to the
Fick principle,the rate at whichthe circulationabsorbs O2 fromthe lungs mustequal?
change in O2 concentration in pulmonaryblood x pulmonary blood flow
3. Between velocityand diameter,which has agreater impact onflow (turbulentflow)?
velocity
4. Considering totalcross sectionalarea, throughwhich bloodvessels is bloodflow the fastest?Slowest? aorta
capillaries5. Does the aorta or
a large arteryhave a greatertension?
Aorta has greater tension.
Laplace's law: change in pressure = 2T/r
6. Explain howanemia leads tohigh outputfailure.
hematocrit reduced
lowered blood pressure
cardiac output raised7. For the Fick
principle, whatblood vessel canbe used forpulmonaryvenous blood[O2]?
peripheral artery
8. For the Fickprinciple, whatblood vessel orchamber of theheart can beused forpulmonaryartery blood?
pulmonary artery or right ventricle9. Hematocrit = packed cell volume/total blood volume10. In the Fick
principle, whatis used for themeasurement ofblood flowthrough thelungs?
pulmonary blood flow11. Is the mean
pressure head ineach majorartery supplyingindividualorgans thesame?
YES12. The largest fall
in bloodpressure acrossthe systemiccirculationoccurs acrossthe _____.
arterioles13. Name 2
vasoconstrictorsof the arterioles.
sympathetic activation
endothelin14. Name 3 factors
which increaseturbulence ofblood flow.
high fluid velocity
large tube diameter
high fluid density, ignored15. Name 3
vasodilators ofthe arterioles.
NO
adenosine
raised K+ levels
Hemodynamics (27)Study online at quizlet.com/_2l20h
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16. Name a factorthat decreasesturbulence.
viscosity
17. A slight increasein vesseldiameter willlead to a large_____ inresistance.
decrease18. The total
resistance of anetwork ofparallelresistances is_____ than theresistance of thesingle lowestresistance.
less
*Total conductance (ease of flow) is thereciprocal of resistance.
19. Veins are verycompliant at_____pressures andcan accomodatelarge increasesin volume.
low20. Velocity of blood
flow is equal to?
flow/area21. What happens
to resistanceand cardiacoutput whenhematocritdecreases?
decrease
increase
22. What happensto resistanceand cardiacoutput when thehematocritincreases?
increase
decrease
23. What heartsounds areheard byauscultation innarrowed bloodvessels?
bruits
24. What iscompliance?
measure of how distensible blood vesselsare, i.e. the relative proportion of elastinversus smooth muscle and collagen.
25. What isLaplace's law?
Change in pressure = 2T/r
26. What is thecritical value ofReynold'snumber?
200027. What is the
equation forcompliance?
volume/pressure
28. What is theequation forresistance(using Darcy'slaw andPouselle's law)?
Resistance = viscosity of fluid/(radius)^4
29. What is theequation forReynold'snumber?
(velocity x diameter x density)/viscosity
30. What is the mostimportantphysiologicalmechanismbehindvasodilation?
reduce sympathetic tone
31. What parameteris associatedwith pulmonaryblood flow?
cardiac output
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32. What principleis used to findthemeasurement ofblood flow?
Fick Principle33. What type of
flow is moreinefficient?
turbulent flow
34. Which requiresmore energy:laminar orturbulent flow?
turbulent flow35. Why are veins
very compliantat lowpressures?
Veins change shape as the pressurewithin them increases, *not due to elastin
36. Why does lowhematocrit leadto heart failure?
decreased resistance
decreased mean arterial pressure
salt and water retention
heart failure37. Why does single
line flow occurin capillaries?
RBC diameter > capillary diameter
38. Why is pressurein an oldperson's aortamuch higherthan that of ayounger person?
less elasticity in the old person's aorta.
39. Why is the aorta morelikely than a smallerartery to develop ananeurysm?
Laplace's law: change in pressure= 2 x tension/radius
Both blood vessels have the samepressure, which means that theaorta has a higher tension since ithas a larger radius.
Hemodynamics (27)