Overview of circulation of hemodynamic principles Flashcards
1
Q
(blank) diseases are the leading cause of death in the USA. CV disease is the cause of more deaths than the next (blank) causes of death combined.
A
CV
5
2
Q
(blank) is the scientific field concerned with the relationship among the physical principles governing pressure, flow, resistance, and compliance as they relate to the cardiovascular system.
A
Hemodynamics
3
Q
Hemodynamics is the scientific field concerned with the relationship among the physical principles governing (blank x 4) as they related to the cardiovascular system
A
Pressure, flow, resistance, and compliance
4
Q
The circulation is a (blank) circuit.
A
closed
5
Q
The circulation is a complete circuit and features a (blank) pattern.
A
branching
6
Q
Blood takes many (blank) from the left heart to the right heart.
A
parallel pathways
7
Q
In most cases blood flows through a (blank)
A
single capillary bed
8
Q
In most cases blood flows through a single capillary bed (e.g., pulmonary circulation) whereas in other cases the blood flows through (blank)
A
two capillary beds in series (e.g., kidney).
9
Q
What is an example of blood flowing through a single capillary bed?
A
pulmonary circulation
10
Q
What is an example of blood flowing through two serial capillary beds?
A
kidney
11
Q
The circulation is a closed circuit that features what type of flow?
A
branching patterns with serial and parallel paths
12
Q
We know blood can flow through a single capillary bed and through capillary beds in series, blood can also flow how?
A
through an arrangement of parallele and series of paths
13
Q
Blood flow from the rigght heart to the left heart can only take a (blank) pathway.
A
single pathway across a single capillary bed in the lungs
14
Q
Some deoxygenated blood (which should have gone to the right heart mixes with oxygenated blood bound for the (blank) arteries.
A
system
15
Q
What type of blood vessels deliver oxygenated blood to the tissues?
A
arteries
16
Q
Since heart is a closed system, if you have a problem in one part of the system will it effect the rest of the system?
A
YES
17
Q
What type of blood vessel transports the blood under high pressure to the tissues?
A
arteries
18
Q
Do all the blood vessels branch?
A
yes
19
Q
What blood vessels have strong vascular walls?
A
arteries
20
Q
What blood vessels have rapid pulsatile blood flow?
A
arteries
21
Q
What blood vessels are densely innervated?
A
arteries
22
Q
Arteriolar resistance is regulated by (blank)
A
ANS
23
Q
What type of adrenergic receptors mediate vasoconstriction on the arterioles of the skin, splachnic, and renal circulation?
A
alpha-1
24
Q
What type of adrenergic receptors mediate vasodilation and are found on arterioles of skeletal muscle and in small coronary arteries?
A
Beta-2
25
What are the smallest branches of the arteries that are 5-100 micron diameter?
arterioles
26
What are the major resistance vessels of the whole peripheral circulation?
arterioles
27
What blood vessels have thick smooth muscle layer?
arterioles
28
What blood vessels have endothelial cell layer and are very densly innervated?
arterioles
29
What type of blood vessels regulate blood flow to the capillary beds and have the biggest pressure drop?
arterioles
30
What are the stopcocks of the circulation?
arterioles
31
What blood vessels have smooth muscle that are partially contracted under normal conditions (basal tone)?
arterioles
32
What type of blood vessels have basal tone?
arterioles
33
What are the main resistance blood vessels? (target these when dealing with blood pressure)
arterioles
34
Factors that control blood flow to the capillaries do so by (blank)
vasoconstriction and vasodialation
35
In order to vasconstrict, you need vessel that is (blank)
not fully constricted to start with
36
In order to vasodilated, you need a vessel that is (blank)
not fully relaxed to start with
37
The smooth muscle surrounding the resistance vessels therefore have (blank).
Basal tone (some level of tonic contraction)
38
What is basal tone?
the consistant slight vasoconstriction of arterioles
39
In contrast to skeletal muscle (which is under nerves control), vascular smooth muscle has some tone without needing (blank).
Neural input
40
The basal tone in arterioles probably comes from (blank)
intrinsic and local factors
41
What blood vessels are the smallest (5-10 micron diameter) with NO smooth muscle?
capillaries
42
Do capillaries have smooth muscle?
no
43
What blood vessels have very thin walls consisting of a single layer of endothelium permeable to small substances?
capillaries
44
What are the major exchange vessels?
capillaries
45
What blood vessels have the largest cross-sectional area?
capillaries (combined cross sectional area, singular cross sectional area are small but together really big)
46
What blood vessels have low flow velocity?
capillaries
47
Can white cells squeeze out of between cells of capillary?
YES!
48
What are small vessels (20 microns) with thin walls?
venules
49
What blood vessels collect blood from capillaries and participate in exchange?
venules
50
Do venules participate in exchange?
yes
51
What blood vessels gradually coalesce into progressibely larger veins and the total cross-sectional area diminshes here and the velocity of blood flow increases?
venules
52
What blood vessels merge to form larger veins and transport blood from tissues back to the heart?
veins
53
What blood vessels are major capacitance vessels=major collection and storage site for blood (major controllable reservoir)
veins
54
What blood vessels have thing BUT muscular walls?
veins
55
What blood vessels are under low pressure and are densely innervated?
veins
56
About 85% of the entire blood volume of the body is in the (blank) , and about 15% in (blank). Of the 85 % in the systemic circulation, ~65% is in the veins, ~13% in the arteries, and ~7% in the systemic arterioles and capillaries.
systemic circulation
| heart and lungs
57
What have greater cross sectional areas, veins or arteries?
veins
58
Blood flow velocity is (blank) in the aorta (small cross-sectional area) than in the sum of all of the capillaries (large cross-sectional area)
higher
59
(blank) is directly proportional to blood flow and inversely proportional to the cross-sectional area at any level of the cardiovascular system.
Velocity
60
What is the equation for velocity of blood flow?
V=Q/A
61
Velocity of blood is inversely proportional to the (blank).
cross-sectional area
62
(blank) is the force exerted by the blood against any unit area of the vessel wall.
Blood pressure
63
The contractions of the heart produce (blank) in the aorta.
hemodynamic pressure
64
Greatest pressure drops at what point?
the arterioles due to branching and high resistance of these blood vessels
65
(blank) stretches blood vessels in proportion to their compliance.
Intravascular pressure
66
As blood flows through the systemic circulation, pressure (blank) progressively because of the resistance to blood flow.
decreases
67
The largest decrease in pressure occurs across the (blank) because they are the site of the highest resistance.
arterioles
68
Because the heart pumps blood continually into the aorta, the mean arterial pressure in the aorta is (blank) , averaging about 100 mm Hg. Also because the pumping by the heart is (blank) , the arterial pressure fluctuates between a systolic pressure level of 120 mm Hg and a diastolic pressure level of 80 mm Hg.
high
| pulsatile
69
Arterial pressure is (blank).
pulsatile
70
Pulsatile pressure is progressively dampened by the (blank) of the arterial walls (compliance) and the functional resistance of the small arteries and arterioles, so that capillary blood flow is essentially nonpulsatile.
elasticity
71
The difference between the peak arterial pressure of systole and the arteriole pressure of diastole (pulse pressure) is damped over the course of the arterial tree due to what?
compliance of the arterial
vessel walls
resistance to flow as vessel
diameter become smaller
72
What is this called:
Reducation of pulse pressure due to
-compliance of the arterial vessel walls
-resistance to flow as vessel diameter become smaller
hydralic filter effect
73
If you are unable to dampen pulsatile flow, what may occur?
graves' disease
74
What disease does this describe:
hyperthyroidism
elevated basal metabolism
arteriolar vasodilation
reduced arteriolar resistance
the dampening effect on the pulsatile arterial pressure is diminished
pulsatile flow in the capillaries is observed in the finger nail beds
Graves' disaese
75
Is arterial pressure constant during the cardiac cycle?
no
76
(blank) is the highest arterial pressure during a cardiac cycle. It is measured after the heart contracts (systole) and blood is ejected into the arterial system.
Systolic pressure
77
(blank) is the lowest arterial pressure during a cardiac cycle. It is measured when the heart is relaxed (diastole) and blood is returning to the heart via the veins.
Diastolic pressure
78
(blank) is the difference between the systolic and diastolic pressures.
Pulse pressure
79
The most important determinant of pulse pressure is (blank) .
stroke volume
80
As blood is ejected from the left ventricle into the arterial system, systolic pressure (blank) because of the relatively low capacitance of the arteries.
increases
81
Because diastolic pressure remains unchanged during ventricular systole, the pulsatile pressure (blank) to the same extent as the systolic pressure.
increases
82
The (blank) gives valuable clues about a person’s stroke volume, provided that the arterial compliance is essentially normal.
arterial pulse pressure
83
Patients who have severe congestive heart failure or who have had a severe hemorrhage are likely to have very (blank) , because their stroke volumes are abnormally small.
small arterial pulse pressures
84
Conversely, individuals with large stroke volumes, as in aortic regurgitation, are likely to have (blank) arterial pulse pressure.
increased
85
Similarly, well-trained athletes at rest tend to have (blank) stroke volumes because their heart rates are usually low. The prolonged ventricular filling times in these individuals induce the ventricles to pump a large stroke volume, and hence their pulse pressures are large.
large
86
The pulse pressure is dampened over the course of the arterial wall tree due to what?
(i) compliance of the arterial vessel wall, and (ii) resistance to flow as vessel diameter becomes smaller
87
Decreases in compliance, such as those that occur with the aging process, cause (blank) in pulse pressure.
increase
88
(blank) is the average arterial pressure with respect to time.
Mean arterial pressure (MAP)
89
What is the equation to determine MAP?
1/3 systolic pressure and 2/3 diastolic pressure
90
(blank) is very low. Veins have a high capacitance and can hold large volumes of blood at lower pressure.
venous pressure
91
(blank) is even lower than the venous pressure. Left atrial pressure is estimated by the pulmonary wedge pressure. A catheter, inserted into the smallest branches of the pulmonary artery, makes almost direct contact with the pulmonary capillaries. The measured pulmonary capillary pressure is approximately equal to the left atrial pressure.
Atrial pressure
92
blood flows when pressure exceeds (blank)
resistance
93
What is ohms law?
```
Blood flow (q)=dP(pressure gradient)/Resistance
Or Q=(mean arterial pressure)/resistance
```
94
The blood flow is directly proportional to the (blank) and inversely proportional to the (blank).
pressure difference, resistance
95
When does Ohm’s law of hydrodynamics work?
any instant of time, regardless of how simple or how complicated the circuit.
96
The pressure gradient (detaP or dP), not the absolute pressure (!), drives (blank) . Thus, blood flows from high pressure to low pressure.
blood flow
97
The (blank) determines flow.
The pressure difference
98
(blank) is the total quantity of blood that can be stored in a given portion of the circulation for each mm Hg pressure rise.
Compliance (capacitance)
99
What is the equation of capacitance or compliance?
C = dV / dP
100
Capacitance is much greater for (blank) than (blank)
veins, arteries
101
Capacitance (compliance) describes the (blank) of blood vessels
distensibility
102
Blood vessels are elastic, and they expand when the blood in them is (blank) .
under pressure
103
(blank) is determined in large part by the relative proportion of elastin fibers versus smooth muscle and collagen in the vessel wall
Capacitance
104
In older adults, are their aortic pressure higher or lower/
higher because arteriesbecome stiffer and less distensible
105
(blank) is caused by the formation of multiple plaques within the arteries. Arteriosclerosis ("hardening of the artery") results from a deposition of tough, rigid collagen inside the vessel wall and around the atheroma. This increases the stiffness and decreases the elasticity of the artery wall.
atherosclerosis
106
(blank) is the force that impedes blood through the system
resistance
107
What are the factors that hcange the resistance of blood vessels?
R= viscosity X vessel length/ radius ^4
108
In the body, the viscosity of the blood or the length of the blood vessel cannot be easily changed from moment to moment. On the other hand, the (blank) of the vessels is constantly changing, and hence the vessel diameter is the major determinant of resistance.
radius
109
(blank) pressure increases the tissue flow due to increased force and vascular wall distention
Increased pressure
110
Inhibition of (blank) activity greatly dilates the vessels and can increase the blood flow twofold or more. Conversely, very strong (blank) stimulation can constrict the vessels so much that blood flow occasionally decreases to as low as zero for a few seconds despite high arterial pressure.
Inhibition of sympathetic
| sympathetic
111
An increase in arterial pressure would cause a proportionate increase in (blank) through the various tissues of the body.
blood flow
112
An increase in arterial pressure not only increases the force that pushes blood through the vessel but also distends the vessels at the same time, which (blank)
decreases vascular resistance.
113
(blank) resistance is illustrated in the systemic circulation
parallel
114
In parallel resistances: the total resistance is less than the resistance of any of the individual (blank)
arteries
115
Each artery in parallel receives a fraction of the total (blank)
blood flow
116
In each parallel artery, the pressure is the (blank)
same
117
Each organ is supplied by an artery that branches off the aorta. This exhibits what kind of resistance
parallel
118
(blank) is illustrated by the arrangements of blood vessels within a given organ.Each organ is supplied by a large artery, smaller arteries, arterioles, capillaries, and veins arranged in series. The largest proportion of resistance in this series is contributed by the (blank) .
series resistance
| arterioles
119
Blood flow through all portions of a closed system that are arranged in series must be the (blank)
same
120
Blood flow through individual vessels arranged in parallel must add up to the (blank) through the system
total blood flow
121
what is the complete resistance that blood encounters as it flows from the arterial to the venous side of the circulation?
total peripheral resistance
122
What is the resistance that the blood encounters as it flows from the capillaries back to the heart.
venous resistance
123
(blank) is fluid’s resistance to flow, “thickness” or internal friction of the fluid.
viscosity
124
The greater the viscosity, the (blank) the flow in a vessel if all other factors are constant.
less
125
(blank)= the percentage of the blood that is cells
~ 42 (men)
~ 38 (women)
hematocrit
126
What is this;
| (increased number of red blood cells). The apparent viscosity in this condition is increased more than twofold.
polycytemia vera
127
The viscosity of normal blood is about (blank) times as great as the viscosity of water (it is mainly due to the large number of red blood cells).
three
128
At relatively low hematocrits,
viscosity is (blank) compared
to plasma, because of
the stickiness of red blood cells.
still higher
129
At higher hematocrits,
| viscosity increases because of (blank).
cell deformation
130
(blank) is streamlined (on a straight line), with each layer of blood remaining the same distance from the wall; also the central portion of the blood stays in the center of the vessel. When laminar flow occurs, the velocity of flow in the center of the vessel is far greater than that toward the outer edges.
Laminar flow (like a cone)
131
(blank) is proportional to driving pressure only under laminar flow conditions.
Flow
132
```
In streamline (or laminar) flow,
(blank) slip over each other, with the highest velocity occurring at the center of the blood vessel and the lowest at vessel wall.
```
concentric rings of fluid
133
As the flow rate increases, red blood cells move toward the (blank) of the blood vessel (axial streaming), where velocity is highest. Axial streaming of red blood cells lowers the apparent (blank) of blood.
center
| viscosity
134
In (blank) the blood flows in all directions in the vessel; the fastest velocities are not necessarily in the middle of the stream
turbulent flow
135
Blood flow is proportional to the pressure gradient until a critical velocity is reached and (blank) results. Because energy is lost in the turbulence, flow does not increase as much for a given rise in pressure after the critical velocity is exceeded.
turbulent flow
136
Reynolds number (and therefore turbulence) is increased by what two things?
decreased blood viscosity
| increased blood velocity
137
The point at which flow changes from laminar (smooth) to turbulent is a function of (blank) expressed in the relationship that became known as the Reynolds number (Ng). This relationship is equally valid for blood moving in the vessels of living organisms and for water moving in pipes.
fluid density, viscosity, and velocity and of the diameter of the vessel
138
The blood flow to each tissue of the body is almost always precisely controlled in relation to (blank)
tissue needs.
139
(blank) is controlled mainly by the sum of all the local tissue flows.
The cardiac output
140
In general, the (blank) is controlled independently of either local blood flow control or cardiac output control.
arterial pressure
