Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Maria physio > week 9 > Flashcards

week 9 Flashcards

(83 cards)

Start Studying
1
Q

at rest what is skeletal muscle primarily regulated by?

A

sympathetic innervation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the receptor types in vascular smooth muscle cells ?

A

a1 and b2 receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are a1 receptors activated by?

A

NE from Sym neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are b2 receptors activated by?

A

E fro sym neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what do a1 receptors lead to?

A

vasoconstriction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what do b2 receptors lead to?

A

vasodilation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what predominates vasoconstriction or vasodilation?

A

vasoconstriction predominates because sym adrenergic neurons primarily activate a1 receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what happens during exercise or fight or flight response?

A

epinephrine released from adrenal glands activates b2 receptors causing vasodilation to increase blood flow to the muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

during exercise, what are the main regulators of blood flow in skeletal muscles and what do they promote?

A

local metabolites byproducts promoting vasodilation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what’s functional hyperemia?

A

increased blood flow to meet the metabolic demands of active tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what’s reactive hyperemia?

A

increased blood flow after a temporary reduction (ischemia), such as when a muscle temporarily compresses blood vessels during contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are the key metabolic signals triggering vasodilation?

A

decreased pO2
increased pCO2
increased lactate (lower pH)
increased potassium (K+)
increased adenosine (from ATP metabolism)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

mechanical compression*****?????

A

exercise-induced compression of blood vessels temporarily restricts flow, causing brief ischemia, followed by reactive hyperemia and vasodilation to restore blood supply

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

at rest, how much blood flows to skeletal muscles?

A

1L/min (20% of cardiac output)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

during exercise, how much blood flows to skeletal muscles?

A

20-30 L/min (20-30x resting level)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what’s the arteriovenous difference in O2 at rest and during exercise?

A

rest - 60 mL O2/L
during exercise - 150 mL O2/L (due to increased oxygen extraction)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what’s considered dynamic exercise?

A

cycles of continuous muscle contraction and relaxation and contraction again

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what does contraction do to arterial inflow?

A

inhibits arterial inflow due to vessel compression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what does relaxation do to arterial inflow?

A

increases arterial inflow as vessels are no longer compressed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what does contraction do to venous outflow?

A

increases venous outflow, enhancing venous return

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what does relaxation do to

A

reduces venous pressure creating a larger pressure gradient supporting increased blood flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what’s considered static exercise?

A

keeping the weight in 1 position when muscles are contracted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what’s the impact of muscle contraction in static exercise?

A

resistance in vessels increases and blood flow decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what happens to total peripheral resistance (TPR) in static exercise?

A

increases.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what happens to mean arterial pressure in static exercise?
increases (systolic and diastolic pressure increase)
26
with increased cardiac output and metabolic activity , what increases in consumption?
higher oxygen consumption
27
what are the metabolic changes leading to vasodilation?
decreased PCO2 increased pCO2 increased. H+ (lower pH) increased K+ increased adenosine from ATP metabolism
28
effect of K+ channels
activation of k+ channels causes smooth muscle hyperpolarizatoin, reducing ca2+ influx leading vasodilation
29
effect of calcium reduction
increased adenosine raises cAMP levels, which further reduces IC ca2+, promoting muscle relaxation and vasodilation
30
from muscles when Ca increases what happens?
increase in ca, leads to NO synthase activation so NO produced by endothelial cells, leading to vsmr so also vasodilation
31
effect of NO release
muscle contraction raises Ca2+ which activates oxide synthase in endothelial cells, NO causes relaxation of VSMC further aiding vasodilation
32
what's splanchnic circulation?
blood flow to abdominal organs, including GI tract, liver, spleen, pancreas
33
flow rate of splanchnic circulation?
1500 mL/min
34
blood supply origins
celiac artery, sup mesenteric artery, inferior mesenteric artery
35
splanchnic circulation functions? (2)
-site of adjustable resistance -major reservoir of blood --> extensive interconnections between arterial branches provide collateral pathways through which blood can reach different parts --> decreases the risk of ischemia during arterial occlusion
36
type regulation in splanchnic circulation
autoregulation
37
postprandial circulation
an increase in blood flow through GI tract after a meal
38
what type of innervation do splanchnic blood vessels receive?
sympathetic innervation
39
during sympathetic contraction of splanchnic arterials, what happens to blood flow?
decreases blood flow to GI tract, which increases blood for organs/ muscles needed for exercise
40
effect of increase in TPR
increase blood to other organs
41
what controls blood flow in coronary circulation
local metabolites
42
most important local metabolite factors in coronary circulation
hypoxia adenosine
43
coronary blood flow Qc at rest
amount of blood heart gets in a minute Qc=200-250 blood/min, 5% of CO 5,6L/min
44
coronary blood flow Qc exercise
1250mL/min
45
ADVO2 value
120-130mL O2/L blood
46
ADVO2 during exercise
900-1200mL/min
47
O2 consumption
30 mL O2/min
48
formula for Qc
Qc = pp/R
49
LCA during systole
-wall tension increases -aortic valve closed -high pressure in myocardium compresses coronary vessels
50
increase in perfusion pressure on LCA during systole
increase in CO increases Perfusion pressure
51
blood flow during diastole
-wall tension decreases -resistance decreases -bood flow increase
52
how is coronary blood flow regulated
myogenic, metabolic and neutral controls
53
myogenic mechanism role in in coronary blood flow
myogenic mechanism (Bayliss effect) provides autoregulation, maintaining stable flow during perfusion pressure (60-160 mmHg)
54
describe how Bayliss effect maintains coronary blood flow
increased arterial pressure causes vasoconstriction to limit blood flow, while decreased pressure causes vasodilation maintaining steady flow
54
mechanism of Bayliss effect at cellular level
increased pressure raises wall tension, activating non-selective cation channels, leading to depolarisation and VDCC activation which increases Ca2+ and causes vasoconstriction
55
what happens at cellular level in Bayliss effect when pressure decreases
decreased pressure reduces wall tension, decreasing activation of cation channels and VDCC leading to less Ca2+ and resulting in vasodilation
56
metabolic regulation
process where factors from metabolism cause vasodilation
57
what happens to o2 and co2 during exercise
o2 decreases, co2 increases which triggers vasodilation
58
what effects cause vasodilation
decreased PO2, increased Co2, increased H+, increased K+ and increased adenosine
59
how does increased heart rate indirectly cause vasodilation
higher heart rate increases CO leading to vasodilation
60
difference between abrupt and gradual occlusion in coronary vessels
-abrupt occlusion leads to necrosis -gradual occlusion allows new vessels to form, reducing damage
61
what primarily controls cerebral circulation
local metabolites, auto regulation and hyperemia
62
most important local vasodilator in brain
increased co2 sensed by central chemoreceptors
63
what effect does increased co2 have on cerebral blood flow
causes vasodilation, increased blood flow to remove excess co2
64
what happens to cerebral blood flow during hyperventilation
Co2 level drop, causing vasoconstriction
65
blood flow in brain
750-800 mL/min & 15% of CO
66
what happens if brain blood flow stops for 5 secs, for 5 mins
loss of consciousness irreversible brain damage
67
auto regulation in cerebral circulation
brains ability to maintain constant blood flow despite changes in pressure
68
what metabolic changes increase cerebral blood flow
increased pCO2, decreased pO2, increased H+, K+ and adenosine lead to vasodilation
69
key regulators of cerebral blood flow
pCO2 and EC K+
70
how do brain vessels respond to high pCO2 levels
they vasodilate to increase blood flow to remove co2
71
effect of hyperventilation on brain vessels
lowers pCO2, leading to vasoconstriction
72
role of astrocytes near neurons
are in close contact with synapses, take up K+ and release them to cause vasodilation
73
what happens if 1 volume component in brain increases
compresses brain tissue, which can cause damage
74
what is Cushing reflex
increased intracranial pressure (ICP) compresses arteries leading to increased blood pressure and decreased heart rate
75
what forms the blood brain barrier and function
capillaries with tight junction that restrict direct access to brain EC fluid, prevents harmful solutes in blood from reaching ec fluid
76
volume and daily production of csf
volume - 150mL production rate - 550 mL/day
77
main functions of csf
provides mechanical protection , allows brain to float and maintains stable environment for neurons
78
where is csf produced
by ependymal cells in choroid plexus
79
how does csf compare to blood composition
csf has low k+, low protein concentration and slightly lower pH
80
how is csf absorbed
passively absorbed through arachnoid vili driven by csf pressure to sup saggital sinus
81
typical pressure of csf
100 mmH2O
82
what happens if csf pressure increases
absorption increases, which leads to brain damage

Maria physio (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions