ICP Flashcards

1
Q

synthesis and storage of glycogen occurs primarily in:

A

the astrocytes- much smaller amount than other organs

acts as an energy buffer that is used up very quickly

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2
Q

the brain can go ____ long without glucose/CBF

A

only a few minutes

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3
Q

Glucose metabolism is a

A

“carrier mediated process” because it requires GUT-1 and GLUT-3 transporters

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4
Q

GLUT-1 transports glucose to _____ GLUT-3 transports glucose to _____

A

astrocytes and endothelial cells/neurons

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5
Q

for adults at rest, ____ is metabolised ______ and even when oxygen is readily available, it has been shown that some anaerobic metabloism takes place in astrocytes and the lactate is then taken up by the neurons

A

90% of glucose aerobically

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6
Q

astrocytes tend to do more _____ because they don’t need as much energy. Neurons do more _____ becasue they metabolize more glucose

A

glycolysis- producing lactate; phosphorylation “astrocyte-neuron lactate shuttle”
;

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7
Q

astrocytes are not as needy (compared to neurons), but they have ______

A

glucose or glycogen that the neurons need if the brain is “in a pinch”

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8
Q

cerebral blood flow is closely coupled to_____. The brain normally extracts 50% of O2 and 10% of glucose from the blood, so if:

A

local cerebral metabolic needs; CSF goes down, the extraction of O2 and glucose goes up: flow metabolic coupling

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9
Q

Pial vessels are surrounded by cerebrospinal fluid (CSF) and give rise to smaller arteries that eventually penetrate into the brain tissue. They essentially smooth muschle tissue that respond to:

A

changes in intravascular pressure, and respond to vasoactive mediators

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10
Q

brain maintains a constant_____ despite fluctuations in ____, and this is done by ______

A

CPP/MAP; varrying the caliber of the pial arterioles (autoregulation)

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11
Q

on the autoregulation chart, the x axis is: and the y axis is______. Flow metabolic coupling:

A

cerebral perfusion pressure (CPP), cerebral blood flow, o2 extraction increases to maintain the level needed

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12
Q

if you had a patient that was hypertensive, they will only be able to ______ at ____. Giving them a mean arterial pressure that is normal (70) will essentially be:

A

autoreglate at higher temperatures; hypotensive for the patient

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13
Q

autoregulation works well between ____, and outside this level, your CBF will ______. So if your cerebral perfusion pressure is low_____

A

60-150, vary directly with your perfusion pressure, CBF will be low

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14
Q

people with hypertension will have autoregulation that is___, and people with a brain injury will have _____. loss of autoregulation can be____.

A

shifted to the right. loss of autoregulation. focal or global in brain injury

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15
Q

loss of autoregulation is due to:

A

pial vessels not doing what they’re supposed to be doing

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16
Q

when autoregulation is no longer in tact, you are more likely at risk for:

A

ischemia when the flow goes down or hemorrage when the flow goes up

17
Q

PaCO2 goes down (hyperventilation), CBF will:

A

drop due to vasoconstriction (the level of O2 needs to remain constant, so decreased CO2 means a decrease in the amount of CBF needed to provide the optimum amount of oxygen)

18
Q

PaCO2 goes up (hypoventilation), CBF will:

A

Increase to balance the ratio of O2 to CO2

19
Q

low PaO2 will cause:

A

vasodilation to increase CBF/blood oxygen flow and maintain O2 concentration

20
Q

we can evaluate CBF and cerebral metabolism by:

A

transcranial doppler (evaluate autoregulation by having the patient hyperventilate), PET scan monitors glucose uptake, CT perfusion to evaluate blood flow, and check for penumbra

21
Q

if blood flow goes away in one spot transiently, it is a _____. If the flow goes away everywhere transiently it is a _____, with permanant loss of blood flow in one spot you have a _____ with permanant loss of blood flow over a wide area you have_____

A

TIA, Cardiac Arrest; ischemic stroke, global brain death

22
Q

doctors will analyze _____ scan to see if there is ____ with _____ which is a sign of _____

A

CT scan (image backwards) an increase in CBF with preserved volume, pernumbra

23
Q

average number for metabolism and CBF is ____, grey matter is a little _____ white is a little ______

A

50 mmHg, higher (nuclei are more metabollically active) lower (axons are metabolically lower)

24
Q

hyperperfusion is a classic finding when _________ is lost when a person has cardiac arrest

A

autoregulation

25
Q

with cardiace arrest, the parts of the brain that are most vulnerable to injury with cardiac arrest

A

gray matter areas in basal ganglia, hippocampus, cerebellum cortex looks the same when you’re going without CBflow or going without glucose

26
Q

principles of _____ and _____ can be used to treat ICP crisis and evaluate brain function

A

cerebral metabolism, blood flow

27
Q

_____ is key in determining CBF

A

Radius of blood vessel; which explains the importance of vasoconstriction and vasodilation

28
Q

____ is the primary feul source for the brain

A

glucose

29
Q

autoregulation serves to;

A

maintain constant CBF and protects brain from ischemia

30
Q

when autoregulation is lost:

A

CBF varies directly with CPP

31
Q

in physiologic range, the ____ varies directly with ____

A

CBF CPP

32
Q

emergency procedures for relieving ICP

A

Sitting upto shunt towards jugular , mannitol osmoregulator, hypertonic saline, cotico steroids, ventricular shunt, hemicraniectomy, hyperventilate,

33
Q

CPP=

A

MAP-ICP

34
Q

CBF=

A

MAP/CPP