ICP

Question 1

synthesis and storage of glycogen occurs primarily in:

Answer 1

the astrocytes- much smaller amount than other organs

acts as an energy buffer that is used up very quickly

Question 2

the brain can go ____ long without glucose/CBF

Answer 2

only a few minutes

Question 3

Glucose metabolism is a

Answer 3

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

Question 4

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

Answer 4

astrocytes and endothelial cells/neurons

Question 5

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

Answer 5

90% of glucose aerobically

Question 6

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

Answer 6

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

Question 7

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

Answer 7

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

Question 8

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

Answer 8

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

Question 9

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:

Answer 9

changes in intravascular pressure, and respond to vasoactive mediators

Question 10

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

Answer 10

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

Question 11

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

Answer 11

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

Question 12

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:

Answer 12

autoreglate at higher temperatures; hypotensive for the patient

Question 13

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

Answer 13

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

Question 14

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

Answer 14

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

Question 15

loss of autoregulation is due to:

Answer 15

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

Question 16

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

Answer 16

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

Question 17

PaCO2 goes down (hyperventilation), CBF will:

Answer 17

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)

Question 18

PaCO2 goes up (hypoventilation), CBF will:

Answer 18

Increase to balance the ratio of O2 to CO2

Question 19

low PaO2 will cause:

Answer 19

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

Question 20

we can evaluate CBF and cerebral metabolism by:

Answer 20

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

Question 21

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_____

Answer 21

TIA, Cardiac Arrest; ischemic stroke, global brain death

Question 22

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

Answer 22

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

Question 23

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

Answer 23

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

Question 24

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

Answer 24

autoregulation

Question 25

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

Answer 25

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

Question 26

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

Answer 26

cerebral metabolism, blood flow

Question 27

_____ is key in determining CBF

Answer 27

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

Question 28

____ is the primary feul source for the brain

Answer 28

glucose

Question 29

autoregulation serves to;

Answer 29

maintain constant CBF and protects brain from ischemia

Question 30

when autoregulation is lost:

Answer 30

CBF varies directly with CPP

Question 31

in physiologic range, the ____ varies directly with ____

Answer 31

CBF CPP

Question 32

emergency procedures for relieving ICP

Answer 32

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

Question 33

CPP=

Answer 33

MAP-ICP

Question 34

CBF=

Answer 34

MAP/CPP