2. Hemodynamics Flashcards

1
Q

Cardiac output from left and right sides of heart are ____, but resistance and pressure are different.

A

equal

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2
Q

What is laminar flow?

A

smooth, streamlined, efficient- velocity slowest at edge and fastest in the center

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3
Q

Turbulent flow produces shearing forces that can damage vascular endothelium, promoting the formation of ______.

A

thrombi and embolisms

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3
Q

What is pulse pressure?

A

systolic pressure - diastolic pressure

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4
Q

What is hydrostatic pressure?

A

blood pressure

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5
Q

What is the flow equation?

A

Q = ?P/R

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6
Q

More compliance in aorta = _____ .

A

lower pulse pressure

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6
Q

How do small, lipid-insoluble molecules diffuse?

A

through inter-endothelial junctions

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7
Q

What is flow equal to?

A

it’s constant through the system

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8
Q

What is pulsatile flow?

A

intermittent pumping that causes flow that is not constant

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9
Q

What determines compliance?

A

relative proportion of elastin fibers versus smooth muscle and collagen in vessel walls

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10
Q

Viscocity mostly depends on ______.

A

hematocrit

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10
Q

For O2, the rate of diffusion from capillary to tissue depends on ______ and on ______.

A

the distance btw the capillary and the tissue; on the amount of O2 carried in blood

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11
Q

Explain v = Q/A

A

velocity depends inversely on cross-sectional area (A)

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11
Q

Where is total XC area smallest? What does this result in?

A

in the aorta; fastest flow

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12
Q

______ decrease total vascular resistance.

A

Parallel vessels

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14
Q

What is Fick?s Principle?

A

the amount used is equal to the amount that enters the tissue minus the amount that leaves

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15
Q

Total resistance in a series of vessels is ____ than the resistance of any individual vessel.

A

higher

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16
Q

LaPlace’s Law is ____.

A

the relationship between tension in a vessel wall and the transmural pressure

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17
Q

What are the major determinants of oncotic pressure in the blood?

A

? Globulin and albumin

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18
Q

As viscocity increases, _____ increases and _____ decreases.

A

resistance; flow

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19
Q

Where does blood pressure fall after the aorta?

A

in the arterioles

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19
Q

Describe x = Q[x].

A

x is the amount of substance x, Q is the flow, and [x] is the concentration of x

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20
Q

Total resistance of a network of parallel vessels is _____ than the resistance of single lowest resistance vessel in the system.

A

lower

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22
Q

What is mean arterial pressure (MAP)?

A

~ diastolic pressure + 1/3(systolic ? diastolic)

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23
Q

_____ from the left and right sides of heart are equal, but resistance and pressure are different.

A

Cardiac output

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24
Q

Where is there no pulse variation?

A

in capillary beds

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25
Q

What does compliance represent?

A

the elastic properties of vessels or chambers of the heart

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26
Q

What is turbulent flow?

A

irregular, with eddies and vortices, requires more pressure

27
Q

Flow is directly proportional to _____ and is inversely proportional to ______.

A

pressure; resistance

29
Q

Where is total XC area greatest? What does this result in?

A

in the capillary beds and pulmonary circulation; slowest flow for areas of exchange

29
Q

What is bulk transport?

A

the movement of substances through the CV system

31
Q

What is velocity (v)?

A

distance per unit time (cm/sec)

31
Q

Capillary oncotic pressure promotes ______.

A

REABSORPTION

33
Q

Explain Flux = k[(Pc-Pi) - (πc-πi)] ** *Starling equation for transcapillary transport

A

Flux = net movement across capillary wall

k = constant

Pc = capillary hydrostatic pressure

Pi = interstitial hydrostatic pressure

πc = capillary oncotic pressure

πi = interstitial oncotic pressure

34
Q

Why is resistance of a capillary bed so low when the pressure is so high?

A

there are many parallel vessels

35
Q

______ is only valid for single vessels.

A

Poiseuille?s Law

36
Q

Two opposing forces determine solvent movement: ____ and ____.

A

hydrostatic pressure and oncotic pressure

37
Q

What is Arteriosclerosis?

A

loss of compliance caused by thickening and hardening of arteries

39
Q

What is cardiac output (CO)?

A

total flow in the CV system

40
Q

______ is the difference in pressure between the inside and outside of a vessel (across the wall).

A

Transmural pressure

41
Q

Flow is ______ to pressure and is _______ to resistance.

A

directly ; inversely proportional

42
Q

Flow varies with _____ power.

A

4th

43
Q

As the length of the vessel increases, _____ increases and _____ decreases.

A

resistance; flow

44
Q

What is oncotic pressure?

A

the osmotic force created by proteins in the blood and interstitial fluid

45
Q

What is the first step in the development of atherosclerotic plaque?

A

damage to vascular endothelium

46
Q

Explain Q = ΔP/R

A

Q = flow (volume/time), ΔP = pressure difference, R = resistance

47
Q

Where is the highest blood pressure?

A

in the aorta

49
Q

What is the total blood volume?

A

5L

49
Q

Factors that increase blood pressure (ie ______) or reduce oncotic pressure (ie _____) tend to promote filtration.

A

hypertension; liver disease

51
Q

Hydrostatic pressure promotes _____.

A

FILTRATION

52
Q

What is transmural pressure?

A

the difference in pressure btw the inside and the outside of a vessel (across a wall)

53
Q

Movement of blood is driven by _____ throughout the CV system.

A

differences in pressure

54
Q

What factors increase turbulent flow?

A

large diameter, high velocity, low viscosity, abrupt changes in diameter, irregularities on tube walls

55
Q

What is flow (Q)?

A

volume per unit time (mL/min)

56
Q

Resistance in series is equal to?

A

adding the individual resistances

57
Q

What drives blood flow through an organ?

A

the difference btw arterial and venous pressure

58
Q

______ describes the relationship between tension in a vessel wall and the transmural pressure.

A

LaPlace?s Law

59
Q

What does CO = ?

A

(mean arterial pressure - venous pressure)/ total peripheral resistance (TPR)

60
Q

Tension in the vessel wall ______ as pressure and radius increase.

A

increases

61
Q

Pulse pressure, mean pressure and velocity all _____ from aorta to capillaries.

A

decrease

62
Q

_____ are more compliant than ____.

A

Veins; arteries

63
Q

MAP depends on?

A

HR

64
Q

_____ produces shearing forces that can damage vascular endothelium, promoting the formation of thrombi and embolisms.

A

Turbulent flow

65
Q

Tension in the vessel wall increases as ______ increase.

A

pressure and radius

66
Q

Cardiac output from left and right sides of heart are equal, but _____ and ______ are different.

A

resistance; pressure

67
Q

Turbulent flow produces shearing forces that can ______, promoting the formation of thrombi and embolisms.

A

damage vascular endothelium

68
Q

What is hematocrit? Normal for men? Women?

A

proportion of RBCs; 42-54% men; 38-46% women

69
Q

What is compliance ( C )?

A

equals change in volume (?V, in ml) that results from a change in pressure (?P, in mmHg)

70
Q

Radius of vessel has huge effect on flow, so doubling the radius increases flow by _____.

A

16-fold (24)

71
Q

In the CV system, _____ is the major mechanism by which flow is controlled.

A

vessel diameter

72
Q

Resistance in parallel is equal to?

A

the sum of the reciprocals of the individual resistances