Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Applied Cardiovascular > Hemodynamics > Flashcards

Hemodynamics Flashcards

1
Q

Bernoulli’s principle says that energy can be changed but not ____

A

Destroyed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Per Bernoulli’s principle, as ____ of fluid flow increases, there is a coexisting reduction in ____

A

velocity; pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Bernoulli’s principle states there will be an ____ in kinetic energy with a ____ in pressure at the site of an obstruction to flow

A

increase; decrease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Based on the conservation of energy principle: If ____ or ____ changes, there will be a change in the other energy to maintain the same level of total energy

A

pressure or kinetic energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

According to Bernoulli’s equation, ____ and ____ are inversely related

A

Velocity and pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

If a vessel has plaque causing a narrowing, the flow velocity will ____ at the site of a stenosis so the pressure must ____

A

increase; decrease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What do we use Bernoulli’s principle to predict?

A
  • The pressure drop (gradient) between two chambers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does Bernoulli’s principle determine?

A
  • Max and mean pressure gradients across stenotic valves
  • Max pressure gradients across regurgitant valve lesions and abnormal shunt communications
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does Bernoulli’s principle estimate?

A

Intracardiac pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the modified Bernoulli’s equation?

A

∆P = 4 (v2^2 - V1^2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the simplified Bernoulli’s equation?

A

∆P = 4(V2^2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does ‘P1’ stand for?

A

Pressure at location 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does ‘P2’ stand for?

A

Pressure at location 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does ‘ρ’ stand for?

A

Density of the blood (1.06 x 10^3 kg/m^3)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does ‘V1’ stand for?

A

Velocity of location 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What does ‘V2’ stand for?

A

Velocity of location 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

When is modified Bernoulli’s equation used?

A

Typically used with aortic stenosis when V1 is > 1.2 m/s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

When is simplified Bernoulli’s equation used?

A

When V1 is </= 1.2 m/s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What does P1 - P2 = ?

A

∆P; or Q

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the pressure in the left ventricle?

A

120 mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the pressure in the aorta?

A

100 mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the pressure in the arterioles?

A

45 mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the pressure in the capillaries?

A

10 mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What does ‘Q’ stand for?

A

Flow volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Arterial Blood Pressure is determined by ____ and ____

A

Volume of blood and resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Equation for pressure

A

Pressure = flow (vol/min) x resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is resistance?

A

The amount of pressure exerted against flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is distensibility?

A

Stretching of arteries or veins to accommodate more blood (systole)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is elasticity?

A

The ability of a vessel to bounce back after being stretched

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is stroke volume (SV)? (definition)

A

The amount of blood pumped out of the heart per beat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the equation for stroke volume?

A

LVOTd^2 x .785 x LVOT⌄TVI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the normal range for stroke volume?

A

70-100 cc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is cardiac output (CO)? (definition)

A

The amount of blood pumped by heart per minute

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is the equation for cardiac output?

A

SV (cc) x heart rate (HR) / 1000

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is the normal range for cardiac output?

A

4-8 L/min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is cardiac index (CI)? (definition)

A

The cardiac output adjusted for Body Surface Area (BSA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is the equation for cardiac index?

A

Cardiac Output (CO) / BSA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is the normal range for cardiac index?

A

2.4 - 4.2 L/m/m^2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What are the three resistance factors?

A

Viscosity, friction, and inertia (acceleration and deceleration)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is viscosity?

A

The thickness of blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What is friction?

A

Movement of blood against the vessels will change some pressure energy to heat

  • there is some loss of the pressure energy to friction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

longer, narrower vessels cause ____ friction

A

more

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is inertia?

A

property of all matter; an object at rest tends to stay at rest, an object in motion tends to stay in motion

  • there is some loss of the energy pressure as inertial losses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What causes inertial losses

A

acceleration and deceleration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What is Poiseuille’s Law?

A

States that flow volume (Q) varies directly with the pressure gradient (Pi-Po) and the fourth power of the radius of the tube (r). Flow (Q) varies inversely with the length (L) of the tube and the viscosity (n) of a fluid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What does (Pi - Po) stand for?

A

Pressure gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What does ‘n’ stand for?

A

Viscosity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What is Poiseuille’s law equation?

A

Q = (Pi-Po) πr^4 / 8nL or
∆P = Q8nL / πr^4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What is Poiseuille’s Law simplified?

A
  • As pressure gradient ↑ flow volume ↑
  • As the tube diameter ↑, flow volume ↑
  • As the length of the tube ↑, flow volume ↓
  • As fluid viscosity ↑, flow volume ↓
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Of all of the factors that effect blood flow, the ____ of the blood vessel is the most significant!

A

radius

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What is velocity? (definition)

A

distance moved over a period of time

52
Q

What is the equation for velocity?

A

velocity = distance x time (V=DxT)

53
Q

What is the unit for velocity?

A

cm/min or M/min

54
Q

What is flow? (definition)

A

amount of blood over time

55
Q

What is the equation for flow?

A

flow = volume/time (F=V/T) or
flow = pressure ÷ resistance

56
Q

What is the unit for flow?

A

mL/min or L/min

57
Q

The less resistance blood meets, the ____ the flow

A

greater

58
Q

Slow flow is important in ____ for the exchange of nutrients and wastes

A

Capillaries

59
Q

Due to reduction in total cross-sectional area (diameter/radius), pressure ____ in the veins until blood reaches the right atrium

A

Decreases

60
Q

Pressure in the venules is ____ than it is in the larger veins

A

Higher

61
Q

____ of veins from capillary bed to IVC/SVC continues to become larger, helping create the energy gradient needed to move flow toward the heart

A

Diameter

62
Q

What is the contraction of the heart during systole, causing blood to surge and strike the arterial walls called?

A

Pulsatile flow

63
Q

The more dramatic the rise and fall of velocity during systole and diastole, the greater the ____

A

Pulsatility

64
Q

This surge can be palpated at points where an artery is close to surface of the skin. As the surge of blood passes and diastole occurs, arteries contract and return to pre-systolic shape/area.

A

Pulsatile flow

65
Q

____ flow occurs further from the heart, especially in the capillaries

A

Steady

66
Q

Steady flow is essential for proper exchange of ____ and ____

A

Nutrients and waste

67
Q

____ do not normally pulsate

A

Veins

68
Q

____ flow (no change with respirations) in a vein may indicate deep vein thrombosis

A

Steady

69
Q

How is blood flow affected by a stenosis?

A

Blood becomes turbulent which reduces the velocity

70
Q

Conservation of energy theory

A

Energy can be changed, not destroyed

71
Q

At stenotic lesion (decrease in diameter) what happens to velocity and pressure? What type of flow pattern is it?

A
  • Velocity is increased
  • Pressure is decreased
  • Disturbed flow pattern
72
Q

At the exit of a stenotic lesion (increase in diameter) what happens to velocity and pressure? What type of flow pattern is it?

A
  • Velocity decreases
  • Pressure increases
  • Turbulent flow pattern
73
Q

In order for a stenosis to be hemodynamically significant (patient has signs and symptoms) , it must be ___% reduced in diameter and ___% reduced in area.

A

50% reduced in diameter
75% reduced in area

74
Q

What is energy?

A

The capacity to do work

75
Q

What is potential?

A

The ability to do work

76
Q

The faster blood moves, the more ____ energy (pressure) is turned into ____ energy

A

Potential; kinetic

77
Q

As blood enters a stenosis (dramatically reducing size of vessel), two things occur:

A
  • Blood changes direction to enter
  • Blood changes direction to exit
78
Q

Usually found at entrance of a great vessel (aorta)

A

Inlet/Plug flow

79
Q

During what flow is the velocity of cells at wall similar to velocities in center of vessel

A

Inlet/Plug flow

80
Q

As vessel size decreases and changes direction, cells at the wall slow in comparison to velocities in center of vessel

A

Parabolic flow

81
Q

Exists when cells move in a forward direction but not in organized layers, as in movement over small amounts of wall plaque

A

Disturbed flow

82
Q

Occurs when the fluid particles move in multiple directions at different velocities. Vortices (whirling blood flow) or Eddies (small circular currents) may develop at turbulent sites.

A

Turbulent flow

83
Q

Reynold’s number (Re)
Predicts the onset of turbulence by using the following four factors

A

velocity (v), density (p), radius (r), and viscosity (n)

84
Q

In cardiovascular imaging, ____ and ____ are constant

A

Fluid density and viscosity

85
Q

What is the equation for Reynold’s number (Re)?

A

Re = flow speed x tube radius x fluid density ÷ fluid viscosity

86
Q

A Reynold’s (Re) value of ____ or greater indicates turbulence

A

2000

87
Q

Resistance

A

Force that exists against layers of moving blood

88
Q

Peripheral resistance

A

Walls of blood vessels offer the most resistance to blood flow

89
Q

The ____ a blood vessel, the more resistance the blood flow meets

A

Smaller

90
Q

Important function of the body is to control ____ blood pressure

A

Arterial

91
Q

Reflexes in the body change the diameter of ____ to help regulate blood pressure

A

Arterioles

92
Q

Arteriole diameter changes either increase or decrease ____ ____

A

Peripheral resistance

93
Q

Arteriole diameter changes are controlled by the ____ ____ in the brain

A

Vasomotor center

94
Q

Stimuli are transmitted to the smooth muscle of the vessel wall via the ____ nervous system

A

Sympathetic

95
Q

Vasodilation

A

Increase in vessel diameter decreases peripheral resistance and lowers blood pressure

96
Q

Vasoconstriction

A

Decrease in vessel diameter increases peripheral resistance and raises blood pressure

97
Q

Lowers heart rate, controls digestion

A

Parasympathetic nerves

98
Q

Increases heart rate, force of heart contraction, controls amount of contractions occurring in arteries and veins

A

Sympathetic nerves

99
Q

What is collateral blood flow?

A

If an artery becomes blocked or occluded, other adjacent vessels may pick up the blood flow

100
Q

Collateral routes are more ____ to flow

A

Resistant

101
Q

What is resistance to flow?

A

The ratio of the pressure gradient across a vessel segment

102
Q

What is the equation for resistance of flow?

A

Rseg = (P1 - P 2) / Q (flow)

103
Q

The cardiac cycle includes all ____ and ____ events in one heartbeat

A

Electrical and mechanical

104
Q

____ events precede ____ events.

A

Electrical; mechanical

105
Q

____ events are graphed on the EKG

A

Electrical

106
Q

P wave represents ____ ____

A

Atrial contraction/ atrial systole

107
Q

QRS represents ____ ____

A

Ventricular depolarization

108
Q

ST segment represents ____

A

Isoelectric period when the heart is refractory to electrical stimulation

109
Q

T wave represents ____ ____

A

Ventricular repolarization (recovery phase of ventricle)

110
Q

What is the definition of Isovolumic Relaxation (IVRT)

A

The time period between semilunar valve closure and MV and TV opening.

111
Q

This time period represents early ventricular relaxation.

A

Isovolumic Relaxation (IVRT)

112
Q

When does ventricular pressures drop below arterial pressures with no change in ventricular volume.

A

Isovolumic Relaxation (IVRT)

113
Q

What are the three components of ventricular diastole?

A
  • Rapid, early diastolic filling-blood enters ventricles passively, yet quickly due to swift ventricular relaxation (E wave)
  • Reduced filling –flow is reduced, pressure begins to equalize (Deceleration of E wave)
  • Diastasis (Time between E and A waves) Seen in slow heart rates
  • Atrial systole
114
Q

____% of ventricular filling occurs during the rapid, early diastolic filling phase

A

70%

115
Q

The period when the ventricles are filling with blood. On the EKG begins with the end of the “T” wave and ends with the onset of the “QRS” complex.

A

Ventricular diastole

116
Q

When are the MV and TV are open and the semilunar valves are closed?

A

Ventricular diastole

117
Q

Occurs at the end of ventricular diastole with the onset of the “P” wave of the EKG.

A

Atrial Systole

118
Q

When are the MV and TV open, and the semilunar valves are close?

A

Atrial Systole

119
Q

Atrial systole contributes ____% of ventricular filling

A

30%

120
Q

The time period between MV and TV closure and semilunar valve opening.

A

Isovolumic Contraction

121
Q

When are all cardiac valves are closes as the ventricles begin to contract.

A

Isovolumic Contraction

122
Q

During isovolumic contraction there is an increase in ____ pressure until ____ pressure is exceeded with no change in volume

A

Ventricular; arterial

123
Q

When does ventricular systole begin?

A

Begins with the closure of the AV valves

124
Q

What corresponds with the onset of the QRS to the T wave on EKG?

A

Ventricular systole

125
Q

Events during ventricular systole occur as follows:

A
  1. Isovolumic contraction (IVCT)
  2. Rapid ejection
  3. Reduced ejection
126
Q

Rapid ejection

A

Semilunar valves open, rapid rise in pressure

127
Q

Reduced ejection

A

Peak ventricular ejection, pressure begins to drop until it’s below great vessel pressure and then the semilunar valves close

Applied Cardiovascular (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions