Cardiac Output, BP, Blood flow Flashcards
(106 cards)
1
Q
1st heart sound
A
AV valves closing
2
Q
2nd heart sound
A
semilunar valves closing
3
Q
look and label wiggers diagram
A
PPT 2 Slide 3
4
Q
look and label the pressure volume curve
A
PPT 2 Slide 4
5
Q
cardiac output equation
A
CO= HRxSV
6
Q
normal CO for men and women
A
men= 5.6L/min women= 4.9L/min
7
Q
what can the average cardiac output get up to during exercise?
A
15-20 L/min
~3 fold increase
8
Q
Does cardiac output increase or decrease with age?
A
decrease
9
Q
angiotensin II
A
circulating hormone
induce release of Ca
release of NE
positive inotropic
10
Q
thyroid hormone
A
regulate metabolism
positive chronotropic and inotropic
hyper/hypo
11
Q
inotropic
A
increase contraction
12
Q
insulin
A
increase glucose uptake
positive inotropic effects
PI3K signaling pathway
13
Q
glucagon
A
increased blood glucose
positive chronotropic and inotropic effects
increases cAMP
14
Q
hypokalaemia
A
low K+ extracellular
hyperpolarizes
cardiac arrest
15
Q
hyperkalaemia
A
excess K extracellular
depolarizes membrane potential
muscle weakness
blocks conduction
16
Q
hypocalcemia
A
cardiac muscle weakness
17
Q
hypercalcaemia
A
increased contraction potentially spastic
18
Q
frank-starling mechanism
A
greater the stretch on resting muscle (preload) the greater the contraction
19
Q
what is stretch determined by?
A
end diastolic volume/pressure
20
Q
starlings law of the heart
A
the energy of contraction of a cardiac muscle fiber is proportional to the initial fiber length at rest
21
Q
venous return
A
amount of blood flow back to the heart
22
Q
how does increased preload change the pressure-volume curve
A
increased preload usually means increased EDV and increased stroke volume
curve gets wider
23
Q
afterload
A
the force that contracting myocytes must overcome
24
Q
what can increase afterload
A
increases in arterial pressure, aortic pressure and aortic stenosis
25
how does afterload change the pressure-volume curve?
height increases due to increase in pressure the LV must create and increases ESV
26
what is the percent of blood in pulmonary circulation
9%
27
what is the percent of blood in the veins, venules, venous sinouses
64%
28
what determines blood pressure and blood flow
vasoconstriction and vasodilation
29
endothelial nitric oxide synthase
```
constitutively expressed (eNOS)
inducible (iNOS)
```
30
what can NO bioavailability be reduced by?
presence of free radicals
31
neural stimulation
```
sympathetic
vasoconstriction (NE)
```
32
endocrine/paracrine
CO2, H+, adenosine
33
artery components
endothelium
elastic tissue
smooth muscle
fibrous tissue
34
arteriole components
endothelium
| smooth muscle
35
capillary components
endothelium
36
venule component
endothelium
| fibrous tissue
37
vein components
endothelium
elastic tissue
smooth muscle
fibrous tissue
38
arteries
expand to hold blood, compliant
| elastic recoil maintains consistant pressure
39
arterioles
smooth muscle and surgace area and can change BF to different tissues
40
capillaries
endothelial cells allow only 1 RBC to pass at a time
41
veins
large diameter
| reservoir for blood
42
what do veins induce and how?
one way blood flow
| one way valves
43
varicose vein
damaged and allows backflow of blood
44
Left ventricle pressure
120/5
45
aorta/ systemic pressure
120/80
46
CVP
7
47
right ventricle pressure
25/1
48
pulmonary arteries
25/8
49
MAP calculation
diastolicx2 + systolic / 3
50
pulse pressure
the difference between systolic and diastolic BP
51
BP equation
MABP= CO x SVR
52
as SV increases what happens to pulse pressure
pulse pressure increases
53
compliance
ability to distend and increase volume with increasing blood pressure
54
as compliance decreases what happens to pulse pressure
pulse pressure increases
55
vascular compliance=
change in volume/change in pressure
56
arteriosclerosis
hardening of arteries
loss of compliance
collagen replaces elastic fibers
increases systolic pressure
57
atherosclerosis
form of arteriosclerosis fat/cholesterol clogs it up
58
new BP goal
<130/80
59
recommendations for stage 1 high blood pressure
lifestyle changes
| exercise
60
recommendations for stage 2 high blood pressure
medication
61
how much do exercise interventions reduce systolic pressure by on average?
4.8 mmHg
62
how much does antihypertensives reduce systolic pressure by on average?
8.8mmHg
63
common causes of Htn
```
obesity
atherosclerosis
renal
endocrine
sympathetic overactive
```
64
problems from Htn
```
endothelial damage
stoke
MI
pathological hypertrophy
HF
```
65
should you put low risk patients on antihypertensives?
no they did not improve mortality or CV outcomes and lead to adverse events
66
flow rate
volume that passes a given point over time (how much)
67
velocity of flow
distance volume of blood will travel in time (how fast)
68
velocity equation
velocity= flow rate/cross sectional area
69
how is velocity related to cross sectional area
velocity is inversely related to cross sectional area
70
blood flow
quantity of blood that passes a given point in the circulation in a given period
71
pressure
blood flows because of pressure gradients
72
resistance
decreases flow
73
ohms law
Flow= change in pressure/ resistance
74
ohms law other equation
CO= (MABP-CVP)/ TSR
75
does absolute pressure drive flow?
no the change in pressure
76
resistance determined by what? what law?
length of tube
radius of tube
viscosity of fluid
poiseuilles law
77
what is radius determined by?
local control- metabolic needs, paracrine agents
circulating horomones
sympathetic reflexes
78
what are arteries, arterioles, capillaries, venules and veins arranged in? why is that important for resistance?
series
| Rtotal= R1+R2+R3
79
what forms parallel? why is that important for resistance?
branching of blood vessels
less resistance overall, more flow
Rtotaly= 1/(1/R1 + 1/R2 + 1/R3)
80
what is the flow through individual arterioles depended on?
dependent resistance of that arteriole
81
increased resistance in arteriole does what to flow?
decreases
82
what is the total blood flow through all the arterioles equal to?
cardiac output
83
why is variation in blood flow to individual tissues possible?
arterioles in the body are arranged in parallel
84
metabolic hyperemia
increase in metabolic products during tissue metabolism induces vasodilation which increases blood flow
85
shear stress control of blood flow
Nitric Oxide
| shear stress causes release of NO and induces vasodilation
86
endothelin
vasoconstriction, released by endothelium
87
NE/E
vasoconstriction
88
angiotensin II
vasoconstriction, found in blood plasma
89
vasopressin (antidiuretic hormone)
vasoconstriction, secreted by posterior pituitary
90
serotonin
mostly vasoconstriction
| released by platelets intestine
91
thromboxane
vasoconstriction released by platelets smooth muscle
92
postacyclin
vasodilation released by endothelial cells
93
bradykinin
vasodilation, in blood plasma, released during inflammation
94
histamine
vasodilation, released during inflammation, allergies by mast cells
95
NO
vasodilation released by endothelial cells
96
ANP/BNP
vasodilation released by the heart during stretch
97
coronary blood flow altered by
contraction
local metabolism
neuronal control
98
baroreceptor locations
```
carotid sinus (glosso)
aortic arch (vagus)
```
99
as BP increases does the firing rate of baroreceptor increase or decrease?
increases and then levels out at max
100
ADH
antidiuretic hormone
secreted by posterior pituitary
water retention
vasoconstriction
101
long term regulation of BP RAAS
renin angiotensin aldosterone system
102
what 5 things does angiotensin II cause?
```
increase in sympathetic
h2o retention
aldosterone secretion
vasoconstriction
ADH secretion
```
103
many cases of HTN can be ascribed to excess weight why?
adipocytes have the angiotensin renin, and ACE that cause HTN
104
ANP, BNP
atrial and brain natriuretic peptides
released by heart when it is stretched
FAIL SAFE FOR VOLUME OVERLOAD
(excrete salt and water)
105
what happens if blood volume decreases due to dehydration or hemorrhage? (hypovolemic)
increase RAAS, decrease baroreceptor firing (increase sympathetic output)
106
what are the common targets of high blood pressure medicines?
```
blood volume
cardiac output (HR or SV)
resistance (vasoconstriction)
```
