CVS 3 Flashcards
1
Q
CO of left heart=
A
co of right heart
2
Q
left sided CO is
A
systemic blood flow
3
Q
right sided CO is
A
pulmonary blood flow
4
Q
what carries blood away from the heart
A
arteries
5
Q
____ are under high pressure
A
arteries
6
Q
the blood volume contained in arteries is called
A
stress volume
7
Q
arteries are thick walled with what type of tissue and muscle
A
elastic tissue and smooth muscle
8
Q
what is the smallest branches of the artieries
A
arterioles
9
Q
where is the highest resistance in CVS
A
the arterioles
10
Q
what controls the arterioles resistance
A
autonomic nervous system
11
Q
alpha 1 adrenergic receptors are found on the arterioles of which 3 areas
A
skin, renal and splanchnic circulation
12
Q
beta 2 adrenergic receptors are found on the arterioles of the___
A
skeletal muscles
13
Q
what has the largest total cross-sectional and surface area
A
capillaries
14
Q
capillaries are the site of exchange for what three things
A
nutrients water and gases
15
Q
what consist of a single layer of endothelial cells
A
capillaries
16
Q
what are venules
A
formed from merged capillaries
17
Q
what carries blood toward the heart
A
veins
18
Q
veins progressively merge to form
A
larger veins
19
Q
what is the pressure for veins
A
low pressure
20
Q
veins are ___ walled, no ____ tissue
A
thin
elastic
21
Q
what innervates the veins
A
autonomic nervous system (alpha 1)
22
Q
which receptor innervates the veins
A
alpha 1 adrenergic receptor
23
Q
the blood volume contained in veins is called___
A
unstressed volume
24
Q
veins contain what proportion of blood in the CVS
A
HIGHEST PROPORTION (65%) reservoir function
25
hematocrit normal person
40-45%
26
hematocrit anemia person
10-20%
27
hematocrit polycythemia
| increase crit increase viscosity=
60-70%
decreased flow rate
28
the percentage of blood that is cells (RBC, WBC, Platelets) is called
hematocrit
29
what three conditions increase blood viscosity
polycythemia
multiple myeloma
hereditary spherocytosis
30
V=
| v=velocity
Q/A
Q=blood flow
A= cross sectional area
31
velocity is directly proportional to
inversely proportional to
proportional to blood flow
inversely proportional to cross sectional area
32
```
velocity as described greatest to least in
capillaries
small veins
arterioles
aorta
```
aorta
arterioles
small veins
capillaries
33
blood flow Q=
change P/R
change P= pressure difference between two ends of vessel
R= resistance
34
what is blood flow inversely proportional to
Blood flow is inversely proportional to the resistance of blood vessels
35
increased resistance=
decrease blood flow
36
decreased resistance
increased blood flow
37
circulation of an adult is how many liters/min
Overall flow in the circulation of an adult is 5 liters/min which is the cardiac output
38
co=
svXhr
39
mean arterial pressure=
co X TPR
40
map =
diastolic + 1/3 pulse pressure
41
pulse pressure=
systolic- diastolic
42
if the HR is too high what is diastolic filling and CO
diastolic filling is incomplete and CO drops
43
Causes of turbulent blood flow:
high velocities
sharp turns in the circulation
rough surfaces in the
circulation
rapid narrowing of blood vessels
44
Turbulence is increased by
decreased blood viscosity
increase blood velocity
45
SVR=
map-cap/COx80
46
MAP=
COxSVR/80+CVP
47
laminar flow - where is the highest velocity
in the middle
48
what does capacitance (compliance) describe
the distensibility of the blood vessels
49
vascular complicance=
volume/pressure
50
compliance- is it greater in the veins or arteries
veins
51
what is the result of capacitance with increasing age
capacitance decreases with age- in old age the arteries becomes stiffer and less distensible
52
capacitance is inversely related to
elastance or stiffness.
the greater the elastic tissue in blood vessel- higher elastance=lower compliance
53
when venous compliance decreases the stress volume
increase- due to shifting of blood from veins to arteries.
54
where is capacitance highest
in the vein
55
where is capacitance low
artery
56
where is capacitance lowest
artery (aging)
57
the force exerted by blood against per unit area of vessel wall
blood pressure
58
where does the largest decrease in pressure occur
across the arterioles because they are the site of highest resistance.
59
pressure is highest in the ___
| pressure is lowest in the ___
highest in the aorta
lowest in the venue cavae
60
as blood flows through the systemic circulation, pressure decreases progressively because of what
resistance to blood flow
61
aorta pressure
100
62
arterioles pressure
50
63
capillaries pressure
20
64
vena cava pressure
4
65
is pulsatile
is not constant during cardiac cycle
what is this?
arterial pressure
66
what is the highest arterial pressure during a cardiac cycle
systolic pressure (120)
67
when is systolic pressure measured
after heart contracts and blood is ejected into the arterial system
68
the lowest arterial pressure during a cardia cycle
diastolic pressure (80)
69
when is diastolic pressure measured
when the heart is relaxed and blood is returning to the heart via veins
70
what is the difference between systolic and diastolic pressures
pulse pressure
71
when capacitance is decrease with aging what happens to the pulse pressure
increased pulse pressure
72
the most important determinant of pulse pressure is stroke volume
increase stroke volume does what to pulse pressure
increase it
decreasing sv decreases pulse pressure
73
Mean Arterial pressure
Is the average arterial pressure with respect to time
| Can be calculated approximately as diastolic pressure plus on-third of pulse pressure
74
venous pressure
The veins have a high capacitance and , therefore, can hold large volumes of blood at low pressure
75
Atrial Pressure
Left atrial pressure is estimated by the pulmonary capillary wedge pressure (PCWP). A catheter (Swan- Ganz) , inserted into the smallest branches of the pulmonary artery, makes almost direct contact with the pulmonary capillaries. The measured pulmonary capillary pressure is slightly higher than the left atrial pressure
76
atrial pressure- pressure measurements
Its an indirect measurement of left ventricular performance
77
a wave
atrial contraction . Absent in atrial fib. Enlarge in pulmonary hypertension
78
c’ wave
RV contraction (tricuspid valve bulging into atrium)
79
v wave
atrial pressure due to filling against closed tricuspid valve. Enlarged in tricuspid regurgitation
80
‘x’ descent:
atrial relaxation + RV contraction (pulls atrium downward)
81
y’ descent:
emptying of right atrium after tricuspid valve opens
82
Cannon wave
large wave not corresponding to a , v or c wave. Due to complete heart block or junctional arrhythmias.
83
cvp reflects
how do we guide fluid replacement
CVP reflects right ventricular preload
Guide during intravenous fluid replacement
84
Anal veins
Hemorrhoids
85
varicose veins.
Faulty venous valves lead to
86
venous pump-
The venous valves and pump maintain a relatively low venous pressure in the legs.
87
what is important in the transport of nutrients to tissues
microcirculation
88
where is the site of waste product removal
micorcirculation
89
in microcirculation, with over 10billion capillaries with a surface area of 500-700 square meters- what is their function
perform solute and fluid exchange
90
the blood flow through the capillaries is regulated by what
contraction and relaxation of the arterioles and the precapillary sphinters
91
what is composed of unicellular layer of endothelial cells surrounded by a basement membrane
capillary wall
92
how does solute and water move across the capillary wall
via the intercellular cleft (space between cells)
93
the most important means by which substances are transferred between plasma and interstitial fluid is by____
simple diffusion
94
what diffuses directly through cell membrane of capillaries
lipid soluble substances (co2, o2)
95
how does water soluble substance move across the capillary wall
intercellular clefts
96
what enhances diffusion across capillary membranes
concentration differences/
| concentration gradient
97
capillaries in different tissues have what distinction in their permeabilities
extreme differences
98
what is the description of the intracellular cleft in the brain
its exceptionally tight (BLOOD BRAIN BARRIER)
99
what is the description of intracellular clefts in the liver and intestine
exceptionally wide
100
why are they intracellular clefts in the liver and intestine very wide
to allow passage of protein
101
what are the capillaries in the liver and intestine called
sinusoids
102
the space between cells is called_____
| the fluid in this space is called____
interstitial
interstitial fluid
103
almost all fluid in interstitium is in form of ___
gel (fluid proteoglycan)
