Arteries and Veins Serving Resistance and Capacitance in the Circulation Flashcards
1
Q
What are the functions of arteries?
A
conduits, hydraulic filter, store blood
2
Q
What are conduits, hydraulic filters and store blood?
A
arteries
3
Q
The principal function of the (blank) is to distribute blood to capillary beds throughout the body.
A
arterial system
4
Q
The principal function of the arterial system is to (blank)
A
distribute blood to capillary beds throughout the body.
5
Q
The (blank) are the terminal components of this system, are high-resistance vessels that regulate the distribution of flow to the various capillary beds.
A
The arterioles,
6
Q
The arterioles, the terminal components of this system, are (blank) that regulate the distribution of flow to the various capillary beds.
A
high-resistance vessels
7
Q
What are the two features of the arterial system that tend to dampen fluctuations in flow?
A
its elastic conduits and high-resistance terminals
8
Q
The body’s arterial system constitutes a (blank)
A
hydraulic filter
9
Q
When the arteries are normally compliant, a substantial fraction of the (blank) is stored in the arteries during ventricular systole. The arterial walls are stretched.
A
stroke volume
10
Q
During (blank) arterial blood flows through the capillaries throughout this phase.
A
systole
11
Q
During (blank) arterial blood continues to flow through the capillaries throughout this phase.
A
diastole
12
Q
During (blank), the previously stretched arteries recoil. The volume of blood that is displaced by the recoil furnishes continuous capillary flow throughout this phase.
A
diastole
13
Q
What are the functions of the veins?
A
conduits, major reservoir of blood, regulate cardiac ouput
14
Q
What has the functions:
conduits, major reservoir of blood, regulate cardiac ouput
A
Veins
15
Q
What are capable of constricting and enlarging and thereby storing either small or large quantities of blood making this blood available when it is required by the remainder of the circulation?
A
Veins
16
Q
What can propel blood forward by means of so-called “pump” and they help to regulate cardiac output.
A
Veins
17
Q
What stores the most blood?
A
veins and venules
18
Q
What is the only blood vessel which have only an intimal layer of endothelial cells resting on a basal lamina?
A
Capillaries
19
Q
The wall of blood vessels consists of three layers, what are they?
A
the intima (tunica intima), the media (tunica media), and the adventitia (tunica adventitia)
20
Q
What does the tunica intima made up of?
A
endothelium
21
Q
WHat is the tunica media made up of?
A
smooth muscle, collagen, elastin
22
Q
What is the tunica adventitia made up of?
A
collagen, fibroblasts, vaso vasorum, nerves
23
Q
Are veins or arteries bigger?
A
veins
24
Q
Do arteries or veins have valves?
A
veins
25
Why are arteries so thick?
due to thick tunica media
26
Conducting or elastic arteries (i.e., aorta, subclavian, pulmonary arteries) are large ones, with very strong and relatively elastic walls, whose function is to (blank) the bulk of blood to regions of the body where it is to be distributed.
“conduct”
27
What are the conducting/elastic arteries?
aorta, subclavian, pulmonary arteries
28
Like a fire hose, (blank) must withstand an enormous head of pressure (the aorta most of all) to pump against the peripheral systemic resistance.
elastic arteries
29
Due to the high pressure in the aorta necessary to pump against peripheral systemic resistance, the wall is heavily reinforced to prevent bursting. The (blank) allow some stretching and “springiness” in response to the pressure, and the (blank) limit the degree of stretch permitted.
elastic fibers
| collagen fibers
30
Once blood has reached the region of distribution (i.e., the limbs) it will be handled by smaller (but still fairly large) distributing or muscular arteries (i.e., femoral, facial, brachial, coeliac), which send it to sub-regions. These vessels have well-distinguished (blank) . The wall of the artery is mostly tunica media comprising almost entirely of smooth muscle cells.
internal elastic lamina
31
Because the pressure in the venous system is very low , the venous walls are (blank)
thin but muscular
32
Do venules have elastic fibers, smooth muscle, or collagen fibers?
NO, only endothelial cells
33
What do all blood vessels except for the capillaries and venules have?
elastic fibers, endothelial cells, smooth muscle, collagen fibers
34
Fibroblasts and nerve endings invade the (blank) and blood cells invade the (blank).
adventita
| Intima
35
Both arteries and veins have (blank)
smooth muscle cells
36
Veins have much thinner (blank) than arteries.
tunica media
37
Smooth muscle cells are (blank) arranged probably forming a spiral or helix with a low pitch. What changes resistance more, length or diameter?
circumferentially
| diameter
38
Veins have much larger cross-sectional areas than (blank).
arteries
39
area and velocity are (blank)
inversely proportional
40
Large veins have little (blank).
resistance
41
Compression by the surrounding tissues generate resistance to (blank)
blood flow
42
What is the force that impedes blood through the system.
resistance
43
Pressure in large veins is (blank) greater than the pressure in the right atrium/
4-7 mmHG
44
Where is pressure higher, in the veins or the right atrium?
veins (rt atrium typically 0 mm Hg)
45
(blank) are high resistance vessels that regulate the distribution of flow to he various capillary beds.
arterioles
46
(blank) have so little resistance to blood flow when they are distended that the resistance then is of almost no importance. ( due to larger cross-sectional area). However when compressed by surrounding tissues this creates the (blank)
Large veins
| 4-7 mm Hg resistance
47
(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)
48
What is the equation for vascular compliance?
vascular complicance= (increase in volume)/(increase in pressure)
49
What are the most distensible blood vessels?
veins
50
(blank) store large quantities of blood.
veins
51
Even slight increases in pressure cause the (blank) to store .5 to 1 liter extra blood.
veins
52
Are all blood vessels distensible?
yes
53
Anatomically, the walls of arteries are far stronger than those of veins, so the (blank), on average, are more distensible than the arteries.
veins
54
What is the equation for compliance?
compliance =distensibility X volume
| C=D x V
55
(blank) depends not only on the distensibility of the vessel, but also on the original volume of this vessel.
Compliance
56
Arteries can change pressure (blank) with a small change in volume while the venous system requires a (blank) change in volume to get any change in pressure
greatly
| HUGE
57
What does changing the diameter of arteries do?
change the direction placement of blood flow
58
What does changing the diameter and pressure of veins do?
It effects cardiac output and venous return
59
(blank) can accomodate a lot of volume without increase the pressure very much
veins
60
What is the concept of delayed compliance?
the idea that blood volume will have a delayed effect on compliance i.e a change in blood will lead to increased or decreased pressure -> compliance will then occur after -> back to almost normal pressure
61
How can a large blood transfusion be related to delayed compliance?
If you increase blood volume you will get a spike in pressure-> delayed compliance will result and then you will get a lower pressure that is closer to normal
62
How can a hemorrage relate to delayed compliance?
if you decrease blood volume you will decrease pressure significantly-> delayed compliance and then and you will get an increase in pressure more close to normal.
63
(blank) is a valuable mechanism by which the circulation can adjust itself over a period of minutes to hours to increased (i.e., blood transfusion) or diminished (i.e., hemorrhage) blood volume.
Delayed compliance
64
Because blood vessels are (blank), blood flow is uninterrupted during the cardiac cycle.
Compliance
65
the aging process diminishes the (blank) of the arteries.
Compliance
66
Do capillaries get blood flow during systole and diastole? How?
yes; blood is stored in arteries during systole-> during diastole this stored blood is given to the capillaries
67
When you age and have less compliant arteries, what happens?
you are unable to store blood during systole so your capillaries dont get blood during diastole
68
When the arteries are normally (blank), blood flows through the capillaries throughout the cardiac cycle.
compliant
69
When the arteries are (blank), blood flows through the capillaries during systole, but flow ceases during diastole.
rigid
70
For any pressure above (blank), the compliance decreases with age.
80 mm Hg
71
For any pressure 80 mm Hg, the compliance decreases with age. This change in compliance is a manifestation of the increased (blank) caused by progressive changes in the collagen and elastin contents of the arterial walls (i.e., atherosclerosis)
rigidity of the system
72
As people age, the pressure-volume curves of their arterial systems shift (blank) , and the slopes of these curves (blank) .
downward
| diminish
73
Is the innervation of blood vessels provided by the sympathetic or parasympathetic nervous system?
sympathetic
74
What generates tyrosine hydroxylase?
sympathetic nerves
75
Blood vessels are innervated primarily by the (blank)
sympathetic nervous system
76
The vasoconstrictor fibers of the sympathetic nervous system supply the (blank).
arteries, arterioles, veins (NOT CAPILLARIES)
77
Which vessels are more responsive to sympathetic nerve stimulation, arteries or veins?
veins
78
Which are more densely innervated by sympathetic fibers, arteries or veins?
veins
79
(blank) contract more in response to sympathetic nerve stimulation that (blank).
veins, arteries
80
What blood vessel is norepinephrine released the most?
vein
81
Veins are more responsive to (blank) hyperactivity
| (i.e. during stress, hemorrhage, exercise) than arteries.
sympathetic
82
If you increase smooth muscle tone via sympathetic stimulation you increase the (balnk) at each volume of the arteries or veins.
pressure
83
sympathetic inhibition decreases the (blank) at each volume.
pressure
84
Explain the effects of sympathetic stimulation
Veins constrict-> large volumes of blood shift to the heart-> pumping by the heart is increased
85
An increase in (blank) throughout the systemic circulation often causes large volumes of blood to shift into the heart, which is a principal method that the body uses to increase the heart pumping.
vascular tone
86
(blank) corresponds roughly to the volume enclosed by the right atrium and the great veins in the thorax.
Central venous pool
87
Blood leave the central venous pool (right atrium) by entering the right ventrical at a rate that is equal to the (blank).
cardiac output
88
If the heart is pumping strongly, the right atrial pressure (central venous pressure, respectively) (blank) .
decreases
89
Anything that affects right atrial pressure affects (blank) everywhere in the body. (the circulation is a closed circuit)
venous pressure
90
What consists of the central venous pool?
great veins in thorax and right atrium
91
(blank) is the average blood pressure within the venous compartment
venous pressure
92
(blank) is the average blood pressure within the peripheral venous pool.
peripheral venous pressure
93
The pressure in the thoracic vena cava near the right atrium (CVP=right atrial pressure)
central venous pressure
94
What is the filling pressure of the right heart?
central venous pressure
95
What is a major determinant of the preload of the right ventricle, which regulates stroke volume through the Frank-Starling mechanism.
Central venous pressure
96
What is the right atrial pressure (central venous pressure)?
0 mm Hg
97
When you have a massive blood transfusion what is your right atrial pressure (central venous pressure)?
20-30 mm Hg
98
When you have CHF what is your right atrial pressure?
4-6 mm Hg
99
Pressure in the chest cavity is what?
-3 to -5 mm Hg
100
What is the pressure in the peritoneal cavity?
6 mm Hg
101
If you are pregnant, have ascites, or an abdominal tumor you peritoneal pressure can rise to (blank)
30 mm HG
102
What is the pressure in the peripheral small veins?
4 to 7 mm Hg
103
A change in CVP is determined by the change in what two things?
change in volume of blood w/in thoracic veins divided by the compliance of these veins
104
CVP is increased by either an increase in (blank) or a decrease in (blank)
venous blood volume
| venous compliance
105
What is an example of decreased venous compliance?
venoconstriction
106
CVP is increased in two ways, what are they?
more volume in venous part of circulation, increased venous tone increases CVP
107
How does central venous pressure (atrial pressure) influence venous return?
The higher the atrial pressure the lower the venous return
108
(blank) is by definition the rate at which blood returns to the thorax from the peripheral vascular bed and thus is the rate at which blood enters the central venous pool.
Venous return
109
The volume of blood returning to the ventricles through veins (venous return) influences (blank)
cardiac output
110
Anatomically, the peripheral venous pool is scattered throughout the systemic organs, but functionally it can be viewed as a (blank)
single vascular space that has a particular pressure (peripheral venous pressure, Ppv) at any instant time.
111
It is the pressure difference between the peripheral and central venous pools that determines (blank)
venous return.
112
If central venous pressure increases then venous return will (blank) because the pressure difference will be lower and you will get less venous return.
decrease
113
How does peripheral venous pressure influence venous return?
increase peripheral venous pressure will increase venous return
114
If you have an increase in volume of blood in veins and increased venous tone you will get an increase in (blank)
peripheral venous pressure
115
If you increase blood volume or venous tone you will shift the venous return graph how?
to the right and up
116
in any stable situation, venous return must equal (blank) or blood would gradually accumulate in either the central venous pool or the peripheral vasculature
cardiac output
117
(blank) curves are simultaneous plots of cardiac output and venous return as a function of the right atrial pressure or end-diastolic volume.
cardiac and vascular function curves
118
The cardiac output or cardiac function curve depicts the Frank-Starling relationship for the ventricle and shows that cardiac output is a function of (blank)
end-diastolic volume
119
(balnk) curve depicts the relationship between blood flow through the vascular system (or venous return and right atrial pressure.
the venous return
120
(blank)is the point at which the vascular function curve interacts with the x-axis and equals right atrial pressure when there is no flow in the cardiovascular system.
Mean systemic pressure
121
(blank) depends on the volume and capacitance of the circulatory system and is an indicator of how full the circulatory system is.
mean systemic pressure
122
(blank) is a theoretical concept about the fullness of the circulation.
Mean systemic pressure
123
(blank) can be measured by stopping blood flow and allowing the pressure throughout the circulatory system to reach equilibrium.
Mean systemic pressure
124
What happens if you increase blood volume?
you will get an increase in mean systemic pressure
increase in venous return
increase in right atrial pressure
increase in cardiac output
125
Mean systemic pressure is increased by an (blank) in blood volume or by a decrease in (blank).
blood volume
| venous compliance
126
If you have decreased venous compliance what will happen to your blood?
will be shifted from veins to arteries
127
An increase in mean systemic pressure is reflected in a shift of the vascular function curve to the (blank)
right
128
Mean systemic pressure is decreased by a decrease in (blank) or by an increase in (blank).
blood volume
| venous compliance
129
If you have an increase in venous compliance what will happen to your blood?
it will be shifted from arteries to veins
130
A decrease in mean systemic pressure is reflected in a shift of the vascular function curve to the (blank)
left
131
On a cardiac output versus central venous pressure (atrial pressure) scale, what is the point at which the 2 points intersect?
the steady state/equilibrium
132
(blank) occurs when cardiac output equals venous return.
Equilibrium
133
Cardiac output can be changed by alternating what?
the cardiac output curve, venous return curve or both
134
If your central venous pressure (right atrial pressure) is increased how do you restore your equilibrium?
If you have high atrial pressure you will have decreases venous return and increase cardiac output for a short period of time and then the system will return to normal.
135
right ventricular (blank) increases via Starling's law.
stroke volume
136
When you increase central venous pressure (right atrial pressure) then you will cause an increase in (blank). The right heart output will temporarily exceed the output of the (blank). As long as this imbalance exists blood will accumulate in the pulmonary vasculature and rises pulmonary venous and left atrial pressure. Increased left atrial pressure increase the stroke volume via starling and you will reach a new (blank).
cardiac output
left heart
steady state
137
If you have ventricular failure you will increase (blank)
right ventricular preload
138
If you increase atrial contractility you will (blank) right ventricular preload.
increase
139
If you increase ventricular compliance you will (blank) right ventricular preload.
increase
140
If you increase venous pressure you will (blank) right ventricular preload.
increase
141
If you increase venous volume you will increase (blank)
venous pressure
142
If you decrease venous compliance you will (blank) venous pressure
increase
143
If you increase inflow resistance you will (blank) right ventricular preload
decrease
144
If you increase outflow resistance and afterload you will (blank) right ventricular preload.
increase
145
If you increase heart rate you will (blank) right ventricular preload
decrease
146
Blood volume, systemic pressure, venous tone, movements by skeletal muscle, intrapleural pressure, venous valves, and suction of relaxed atrium are all factors affecting (blank)
venous return
147
The return of flow of blood to the heart is facilitated by what??
large diameter of veins, one way valves, skeletal muscle contraction and respiration
148
IS the pressure in your feet higher than the pressure in your heart?
yes
149
(blank) is the pressure that results from the weight of water (i.e., of blood in human body).
hydrostatic pressure
150
(blank) is the concept that in any body of water, the pressure at the surface of the water is equal to the
atmospheric pressure, but the pressure
rises below the surface.
toricceli law
151
WHat increases venous return and decreases venous volume?
the muscle pump
152
When are the valves closed?
after contraction
153
What break up the hydrostatic columnn of blood, thus lowering venous and capillary hydrostatic pressure?
the valves of veins
154
(blank) carry blood away from heart
artery
155
(blank) has blood that is under great pressure
artery
156
(Blank) have thick and elastic muscular walls and no valves
arteries
157
(Blank) carry oxygenated blood
arteries
158
```
What is this?
1. Carry blood towards
the heart.
2. Blood is not under great
pressure.
3. Have relatively thin slightly
muscular walls.
4. Have semi-lunar valves along
their lengths to prevent back
flow of blood.
5. Carry deoxygenated blood
```
veins
