Arterial and Venous System and Lymphatics Flashcards
(93 cards)
1
Q
The least amount of damping of the pressure pulses would occur in which of the following components of the circulatory system? A.) Femoral Artery B.) Arterioles C.) Capillaries D.) Venles
A
A.) femoral artery
2
Q
Which of the following factors affect(s) pulse pressure? A.) Vascular Elastance B.) Arterial Compliance C.) Stroke Volume D.) All of the Above E.) B and C only
A
E.) B and C only
3
Q
Which of the following is the most important means for the exchange of substances between the blood and the interstitial fluid?
A.) Blood hydrostatic pressure
B.) Capillary oncotic pressure
C.) Diffusion
D.) Interstitial fluid hydrostatic pressure
E.) Osmosis
A
C.) diffusion
4
Q
Vascular distensibility=?
A
Increase in volume/ (increase in pressure x original volume )
5
Q
Veins are about _____ times more distensible than arteries
A
8
6
Q
Pulmonary vein distensibilities are about the same as for what
A
systemic veins
7
Q
Pulmonary artery distensibilities are about ____ times that of systemic arteries
A
6
8
Q
Vascular compliance (capacitance) = ?
A
Increase in volume/ increase in pressure
9
Q
Capacitance describes what
A
The distensibility of blood vessels
10
Q
What does Vascular compliance (capacitance) tell us
A
the total quantity of blood (ml) that can be stored in a given portion of the circulation for each mm Hg rise in pressure
11
Q
Capacitance is inversely proportional to ?
A
Elastance
12
Q
Compliance is = ?
A
distensibility x volume
13
Q
Capacitance is directly proportional to ?
A
Volume
14
Q
Capacitance is inversely proportional to ?
A
Pressure
15
Q
Capacitance is much greater in ____ than arteries
A
Veins
16
Q
Capacitance of arteries _______ with age
A
Decreases
17
Q
The greater the amount of elastic tissue in a blood vessel the ______ the elastance
A
Higher
18
Q
The greater the amount of elastic tissue in a blood vessel the ______ the compliance
A
Lower
19
Q
Vascular compliance=
A
total quantity of blood that can be stored in a given portion of the circulatory system
20
Q
What is compliance
A
is a measure of the ease with which a hollow viscus may be distended
21
Q
What is Elastance
A
Measure of the tendency of a hollow viscus to recoil toward its original dimensions upon removal of a distending or collapsing force
22
Q
A systemic vein is about 8 times as distensible as its corresponding artery and has a volume about 3 times as great. How would its compliance compare to that of a corresponding artery?
A
24
23
Q
Pulse pressure=
A
Stroke Volume/ Arterial Compliance
24
Q
What is the most important determinant of pulse pressure?
A
Stroke volume output of the heart
25
Pulse pressure increases to the same extent as the ________
Systolic pressure
26
Diastolic pressure remains unchanged during ___________
Ventricular systole
27
What are two factors affecting the pulse pressure
Stroke volume output of the heart, compliance of the arterial tree
28
Decreases in compliance (capacitance) (i.e. aging), results in a ______ in pulse pressure
increase
29
Conditions causing abnormal contours of the pressure pulse wave
Aortic valve stenosis, Atherosclerosis, Patent ductus arteriosus, Aortic regurgitation
30
Due to aortic valve stenosis the blood flow into the aorta is
diminished
31
What is aortic stenosis and what is its effect on aortic pressure
Stenosis of the aortic valve leading to decrease in aortic pulse pressure
32
What is patent ductus arteriosus
Half or more of the cardiac output flows back into the pulmonary artery and lung blood vessels
33
What are two conditions that case abnormal contours of the pressure pulse wave
Patent ductus arteriosus
| Aortic regurgitation
34
In a pt with patent ductus arteriosus what happens to diastolic pressure before the next heartbeat
It falls very low
35
What is aortic regurgitation
Blood flows back into left ventricle,
| aortic valve is absent or will not close completely
36
What happens to the aortic pressure between heartbeats in a patient with aortic regurgitation
It may fall all the way to 0 between heartbeats
37
The progressive reduction of the pulsations in the periphery= _______ of the pressure pulses
Damping
38
What is the name of the sounds heard by the stethoscope when checking blood pressure
Korotkoff
39
When do you stop hearing sounds when checking blood pressure
When the pressure in the cuff is equal to or lower than diastolic pressure
40
Mean arterial pressure is the average _____ pressure with respect to time
Arterial
41
why is the mean arterial pressure not simply the average of diastolic and systolic pressures
because more of the cardiac cycle is spent in diastole
42
what is the equation for mean arterial pressure
mean arterial pressure= diastolic pressure + 1/3 pulse pressure
43
Central venous pressure is equal to what
pressure in the right atrium
44
What are the factors that regulate right atrial pressure
Ability of the heart to pump blood out of the right atrium/ventricle
tendency of blood to flow into the right atrium
45
How do you estimate left atrial pressure
Use pulmonary wedge pressure:
catheter inserted into the pulmonary artery will make almost direct contact with the pulmonary capillaries. This pressure is almost equal to the left atrial pressure.
46
What are some factors that increase venous return (and increase right atrial pressure)
increased blood volume
increased peripheral venous pressures due to increased large vessel tone.
Dilation of the arterioles
47
Do large veins have some resistance
yes
48
in a person lying down the pressure in peripheral veins is _______mm Hg greater than the right atrial pressure
+4 to +6
49
When intra-abdominal pressure increases, what must happen for the venous blood in the legs to pass the abdomen
The venous pressure in the legs must increase above the abdominal pressure before blood can flow from the legs to the heart thought the abdominal veins
50
Where are varicose veins most often present
in the superficial veins secondary to valve issues
51
What is the name for the veins that connect the superficial veins to the deep vein
perforating veins
52
_______ control blood flow to each tissue
Small arterioles
53
______ in tissues control diameters of arterioles
local conditions
54
Arterioles are highly ________
Muscular
55
Where is the continuous muscular coat of an arteriole lost
in the metarterioles
56
______ encircles capillary at point where it originates form a metarteriole
Smooth muscle
57
What is the precapillary sphincter
Smooth muscle fibers encircle capillary at point where it originates from a metarteriole
58
How many layers is the capillary wall
unicellular layer of endothelial cells
59
The capillary wall has a thin what
basement membrane
60
what is the total thickness of a capillary wall
0.5 micrometers
61
What is the internal capillary diameter
4-9 micrometers
62
What are slit pores in a capillary
intercellular clefts; spacing of 6-7 micrometers
| allow for rapid diffusion of water, water-soluble ions, and small solutes
63
What are the plasmalemmal vesicles of a capillary formed from
Caveolins
64
What is the role of plasmalemmal vesicles in a capillary
Play a role in endocytosis and transcytosis
65
Name three organs that have capillaries with pores
Liver, GI tract, kidneys
66
What is the most important factor in regulating vasomotion
Concentration of oxygen in the tissues
67
What is the most important means for the exchange of substances between the blood and the interstitial fluid
Diffusion
68
_____ substances can diffuse readily through the capillary cell membranes: give two examples
lipid-soluble, oxygen, and Carbon dioxide
69
Non-lipid-soluble substances diffuse through the
intercellular pores/clefts
70
The rate of water diffusion through the capillary membrane is _____ than flow of plasma within the capillary
80x faster
71
The rate of diffusion is directly proportional to what
Concentration differences of the diffusing substances
72
Passage of substances through the interstitium is mostly via ____ rather than ____
diffusion rather than flow.
73
Passage of substances though the interstitium is mostly via diffusion rather than flow because of
The large numbers of proteoglycan filaments found in the interstitium
74
_____ that allow fluid flow through the interstitium do sometimes form
Rivulets
75
what are rivulets
"free" fluid and small free fluid vesicles
| means fluid that is free of the proteoglycan molecules ad therefore can flow freeely
76
_____ determine direction of diffusion into or out of a capillary
Starling forces
77
What are the 4 starling forces
Capillary pressure (outward force)
Interstitial fluid pressure (inward force)
Capillary plasma colloid osmotic pressure (inward force)
Interstitial fluid colloid osmotic pressure (outward force)
78
sum of starling forces equals
net filtration pressure
79
Capillary filtration coefficient
takes into consideration the number and size of pores
| not all capillaries are equal
80
Filtration=
Kf (capillary filtration coefficient) x NFP
81
osmotic pressure caused by the plasma proteins is called
colloid osmotic pressure
82
When fluid enters the lymphatics, the lymph vessel walls contract momentarily to what
pump fluid into the blood circulation
83
When fluid enters the lymphatics, the lymph vessel walls contract momentarily and creates a slight ______ pressure in the interstitial spaces
negative
84
What is the mean net outward force
0.3
85
The mean forces tend to move fluid
Outward
86
The lymph vessels possess ____ valves
1-way
87
Lymph flow reaches maximum when
interstitial pressure rises slightly above atmospheric pressure
88
What is the capillary pressure (Pc)
Tends to force fluid outward through the capillary membrane
89
What is the interstitial pressure (Pif)
tends to force fluid inward through the capillary membrane when Pif is positive but outward when Pif is negative
90
What is the capillary plasma colloid osmotic pressure
tends to cause osmosis of fluid inward through the capillary membrane
91
The interstitial fluid colloid osmotic pressure
tends to cause osmosis of fluid outward through the capillary membrane
92
Factors that increase lymph flow (and also interstitial fluid pressure)
Elevated capillary hydrostatic pressure
decreased plasma colloid osmotic pressure
increased interstitial fluid colloid osmotic pressure
Increased permeability of capillaries
93
Rate of lymph flow =
interstitial fluid pressure x activity of lymphatic pump
