Chapter 5: Arterial Physiology Flashcards
1
Q
The tendency of a body at rest to stay at rest or a body in a motion to stay in motion
A
inertia
2
Q
The energy of work or motion; in the vascular system, it is, in part, represented by the velocity of blood flow
A
kinetic energy
3
Q
Flow of a liquid in which it travels smoothly in parallel layers
A
laminar flow
4
Q
The law that states the volume of a liquid flowing through a vessel is directly proportional to the pressure of the liquid and the fourth power of the radius and is inversely proportional to the viscosity of the liquid and the length of the vessel
A
Poiseuille’s Law
5
Q
The stored or resting energy; in the vascular system, it is the intravascular pressure
A
potential energy
6
Q
The property of a fluid that resists the force tending to cause fluid to flow
A
viscosity
7
Q
Total energy of a system is made up of both _____ and _____ energy.
A
potential
kinetic
8
Q
stored or resting energy; represented primarily by intravascular pressure which distends vessels; supplied by contraction of heart
A
potential energy
9
Q
energy of work or motion
A
kinetic energy
10
Q
highest pressure equal to 120 mm HG is found:
A
left ventricle of heart
11
Q
Lowest pressure equal to 2-6 mm Hg
A
right atrium of heart
12
Q
potential for doing work related to force of gravity
A
gravitational potential energy
13
Q
pressure within vessels related to reference point of right atrium
A
hydrostatic pressure
14
Q
The farther below the reference point, the _____ the hydrostatic pressure.
A
greater
15
Q
Gravitational potential energy and hydrostatic pressure tend to:
A
cancel each other out
16
Q
describes the relationship of energy, velocity, and pressure
A
Bernoulli Principle
17
Q
when a fluid flows without a change in velocity from one point to another, the total energy content remains constant, providing no frictional losses
A
Bernoulli Principle
18
Q
Energy is almost all dissipated in the form of heat because of ____.
A
friction
19
Q
balance between potential energy (pressure) and kinetic energy (velocity)
A
total energy
20
Q
If the velocity of blood goes up, there must be a pressure ____>
A
decrease
21
Q
Energy “losses” are the result of ____ and ____.
A
viscosity
inertia
22
Q
the property of a fluid that resists the force tending to cause fluid to flow; friction existing between bordering layers of fluid
A
viscosity
23
Q
_____ increases with increases in hematocrit
A
viscosity
24
Q
most important influence of blood viscosity
A
hematocrit
25
tendency of a body at rest to stay at rest or a body in motion to stay in motion unless acted upon by an outside forece
inertia
26
occur whenever blood is forced to change direction
inertial losses
27
Energy losses because of viscosity effects are ____ than those because of inertia
greater
28
rate of movement (displacement) with respect to time
velocity
29
units of velocity
distance per unit of time
cm/s; m/s
30
also referred to as volume flow
blood flow
31
represents the volume of something moved per unit of time
blood flow
32
units of blood flow
mL/s; L/s; mL/min; L/min
33
Velocity will vary inversely with _______
cross sectional area
34
velocity must ____ if area of a blood vessel decreases/
increase
35
The cross sectional area _____ moving from aorta, through arteries, then arterioles, into capillaries
increases
36
Blood velocity _____ as blood travels from aorta, through arteries, then arterioles, into capillaries
decreases
37
Why is the slowing down of blood flow important at the capillaries?
important in proper exchange of nutrients and waste
38
As blood is returned to the heart, velocity _____.
increases
39
describes the steady laminar flow of Newtonian fluids
Poiseuille's Law
40
refers to a system where flow is nonpulsatile
steady flow
41
flow that moves in a series of layers
laminar flow
42
homogeneous fluid
Newtonian fluid
43
used to define pressure/flow relationships
Poiseuille's Law
44
A greater change in pressure will produce a(n) _____ in flow.
increase
45
If viscosity of blood increases, flow will ____.
decrease
46
radius of a vessel is directly proportional to
flow
47
most important determinant of blood flow
radius of blood vessel
48
states that the current (flow) through two points is directly proportional to the potential difference or voltage across the two points and inversely proportional to the resistance between them
Ohm's Law
49
What varies resistance by altering vessel radius?
smooth muscle cell layer within media of wall of vessel
50
For resistance in series, the total resistance equals to the sum of _______
individual resistances
51
For resistances in parallel, the _____ of the total resistance of the system equals the sum of the reciprocals of the individual resistances
reciprocal
52
The more parallel elements in a network, the _____ the overall resistance
lower
53
antegrade flow throughout cardiac cycle
low-resistance flow
54
low-resistance flow arteries
internal carotid
vertebral
celiac
splenic
hepatic
renal
55
displays both antegrade and retrograde flow
high-resistance flow
56
Radius of vessel decreases, _____ resistance to flow
increases
57
arteries with high-resistance flow
external carotid
subclavian
distal aorta
iliac
fasting superior mesentary
resting peripheral arteries
58
Low resistance pattern results in a(n) _____ in blood flow to meet the increased metabolic demands
increase
59
entrance to a vessel flow; all elements of blood flow stream will have the same velocities
plug flow
60
Velocity is equal to approximately _____ the mean velocity across the entire cross section.
twice
61
irregular motions of fluid elements
turbulent flow
62
dimensionless quantity
Reynolds number
63
proportional to inertial forces and to viscous forces acting on a fluid
Reynolds number
64
directly proportional to velocity of blood, density of blood, and radius of vessels
Reynolds number
65
inversely proportional to viscosity of blood
Reynolds number
66
Re below 2000
flow will be laminar flow
67
Re above 2000
turbulence will develop
68
Principal function of the arterial system
distribute blood to the capillary beds throughout body
69
converts intermittent (pulsatile) output of heart to a steady flow through capillaries
hydraulic filtering
70
entire stroke volume discharged; part of energy of cardiac contraction dissipated as kinetic energy of the forward blood flow; remained stored as potential energy by distensible arteries
systole
71
elastic recoil of arterial wall converts potential energy into blood flow; produces antegrade flow late in cycle
diastole
72
change in volume divided by the change in pressure represents ______.
capicitance or compliance
73
the difference between systolic and diastolic pressures
pulse pressure
74
arterioles are known as _____ vessels
resistance
75
nerve fibers release norepinephrine because it causes:
an increase in tone of arterioles
76
resistance vessels _____ in response to high blood pressure and ____ in response to low blood pressure
dilate
constrict
77
2 lesions that are areas of concern for artherosclerosis
fibrous and complicated plaque
78
smooth surface, composed of smooth muscle and fibrous tissue, lacks calcification
fibrous plaque
79
irregular surface, loss of normal endothelium and calcification present
complicated plaque
80
Viscous energy losses within a stenosis are inversely proportional to _______ and directly proportional to its ____.
fourth power of radius
length
81
small change in radius = ____ change in flow
large
82
Doubling in length yields a _____ in associated energy losses
doubling
83
Decrease in radius by half will _____ energy losses by a factor of 16.
increase
84
degree of narrowing at which pressure and flow begin to be affected
critical stenosis
85
Changes in pressure and flow do not occur until cross-sectional area has been reduced by ___%>
75
86
preexisting pathways that enlarge with a stenosis or occlusion
collateral vessels
87
Collateral vessels are divided into:
stem arteries, midzone collaterals, reentry arteries
88
Blood flow increases with exercise to at least ____ times resting flow
3-5
89
Energy within the vascular system is made up of potential energy stored as _________ and kinetic energy represented by the _____.
intravascular pressure
velocity of moving blood
90
The hemodynamics of the arterial system includes unique relationships between ____, ______, and ____>
pressure
resistance
flow
91
Blood flow is determined by changes in ____ and _____.
pressure
resistance
92
The greatest impact to blood flow is the ______.
radius of a blood vessel
93
______ are the main source of resistance within the vascular system
arterioles
94
the energy of work or motion; in the vascular system, it is in part represented by the velocity of blood flow
kinetic energy
95
the stored or resting energy; in the vascular system, it is the intravascular pressure
potential energy
96
Flow of a liquid in which it travels smoothly in parallel layers
laminar flow
97
the law that states the volume flow of a liquid flowing through a vessel is directly proportional to the pressure of the liquid and the fourth power of the radius and is inversely proportional to the viscosity of the liquid and length of the vessel
Poiseuille's Law
98
the tendency of a body at rest to stay at rest or a body in motion to stay in motion
inertia
99
The property of a fluid that resists the force tending to cause fluid to flow
viscosity
100
Where in the vascular system is the lowest energy represented by the lowest pressure located?
the right atrium
101
Which of the following statements regarding gravitational energy and hydrostatic pressure is FALSE?
a. they are components of the total energy in the vascular system
b. They tend to cancel each other out
c. They are components of the kinetic energy in the vascular system
d. They are expressed in relation to a reference point
c
102
What causes blood in the vascular system to move from point to the next?
pressure or energy gradient
103
In the entire vascular system, how does the cross-sectional area of vessels change?
increases from the aorta to the capillary level
104
Which of the following statements regarding the velocity of blood flow is FALSE?
a. velocity refers to the rate of displacement of blood in time
b. the velocity of blood increases from the capillaries to the venous system
c. the velocity of blood increases from the aorta to the capillaries
d. the velocity of blood changes with cross-sectional areas of the vessels
c
105
Which of the following could NOT be used as a unit to measure flow volume?
a. mL/s
b. m/s
c.cL/min
d. L/min
v
106
In the vascular system, what represents the potential difference or voltage in Ohm's law?
pressure gradient
107
Changes in which of the following will most significantly affect resistance in the vascular system?
a. volume flow
b. velocity
c. viscosity of blood
d. radius of vessels
d
108
When vessels are arranged in parallel, how does this affect the entire system?
lower total resistance than when vessels are in series
109
Which of the following characterizes low-resistance flow?
a. retrograde flow
b. alternating antegrade/retrograde flow
c. antegrade flow
d. constriction of arteriolar bed
c
110
Which of the following characteristics regarding high-resistance flow is false?
a. the flow profile may be two to three phases
b. the flow displays alternating antegrade/retrograde flow
c. the flow profile is owing to vasoconstriction of arterioles
d. the flow profile is owing to vasodilation of arterioles
d
111
What flow profile is typically demonstrated at the entrance of a vessel?
plug flow
112
Which of the following statements regarding laminar flow is FALSE?
a. the layers of cells at the center of the vessels move the fastest
b. the layers of cells at the wall of the vessels do not move
c. The velocity at the center of the vessels is half the mean velocity
d. The difference in velocities between layers is owing to friction
c
113
What is required to move blood flow in a turbulent system?
greater pressure
114
What is the function of the hydraulic filter of the arterial system (composed of elastic arteries and high-resistance arterioles)?
distribute flow to the capillaries
115
In diastole, how is the conversion of potential energy into blood flow accomplished?
elastic recoil of the arteries
116
How is the resistance in the arterial system controlled/
by the contraction and relaxation of smooth muscle cells in the media of arterioles
117
Which of the following will result when norepinephrine is released by the sympathetic nervous system?
a. the relaxation of smooth muscle cells in arterioles is triggered
b. the contraction of smooth muscle cells is triggered
c. no effect on the smooth muscle cells in arterioles
d. no effect on the tone of the arteriole walls
b
118
Most prominently, abnormal energy losses in the arterial system would result from pathologies such as obstruction and/or stenoses because of which of the following?
a. the increased length of the stenosis
b. the friction from the atherosclerotic plawue
c. the decrease in the vessel's radius
d. the increased viscosity
c
119
Which of the following statements about collateral vessels is FALSE?
a. collaterals are preexisting pathways
b. the resistance in collaterals is mostly fixed
c. vasodilator drugs have a large effect on collaterals
d. midzone collaterals are small intramuscular branches
c
120
In the human body, the major component of the blood influencing viscosity is ____.
hematocrit
121
The highest pressure in the vascular system is found in the _____.
left ventricle of the heart
122
When moving farther from the reference point of the right atrium, the hydrostatic pressure is _____.
reduced
123
The principle stating that the total energy remains constant from one point to another without changes in flow velocity is _____.
Bernoulli's Principle
124
Inertia and viscosity are two components of the vascular system contributing to ____.
energy "losses"
125
In the vascular system, if the volume of blood or flow remains the same, a decrease in the area of a vessel should trigger a(n) ______ in the velocity of blood.
increase
126
The law defined by the statement that the current through two points is directly proportional to the potential difference across the two points and inversely proportional to the resistance between them is _____.
Ohm's law
127
The total resistance in a system where the elements are arranged in a series is the ____ of the individual resistances/
sum
128
A low-resistance flow profile characteristically displays ______ flow throughout the cardiac cycle/
antegrade
129
The third antegrade phase seen in a high-resistance flow profile is related to _____ of the proximal vessels.
compliance
130
After exercise, under normal conditions, the resistance of the tissue bed in the lower extremities will change from _______.
high resistance to low resistance
131
In laminar flow, the "layers" of cells at the center of the vessel move _____ than the layers closest to the wall of the vessel.
faster
132
Turbulence in a blood vessel is mostly the result of change in the velocity of blood and the ____ of the vessel.
radius
133
The Reynolds number above which turbulence of flow starts to occur is _____.
2000
134
The arterial system can be compared to the ______ of the resistance-capicitance filters of an electrical circuit.
hydraulic filter
135
Pulse pressure in the arterial system is the difference between _____ and ______ pressure.
systolic
diastolic
136
An example of a local feedback mechanism that controls blood flow is that a drop in interstitial _____ will trigger the arterioles to dilate.
oxygen
137
In an area of atherosclerotic plaque, the exposure of the subendothelial collagen matrix is _______ and may cause platelet accumulation.
thrombogenic
138
Energy losses caused by stenosis will be more pronounced with less diameter reduction in a ____ resistance system.
low
139
Under normal conditions with exercise, blood flow _____ by at least three to five times the resting value.
increases
140
