ICP Flashcards
synthesis and storage of glycogen occurs primarily in:
the astrocytes- much smaller amount than other organs
acts as an energy buffer that is used up very quickly
the brain can go ____ long without glucose/CBF
only a few minutes
Glucose metabolism is a
“carrier mediated process” because it requires GUT-1 and GLUT-3 transporters
GLUT-1 transports glucose to _____ GLUT-3 transports glucose to _____
astrocytes and endothelial cells/neurons
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
90% of glucose aerobically
astrocytes tend to do more _____ because they don’t need as much energy. Neurons do more _____ becasue they metabolize more glucose
glycolysis- producing lactate; phosphorylation “astrocyte-neuron lactate shuttle”
;
astrocytes are not as needy (compared to neurons), but they have ______
glucose or glycogen that the neurons need if the brain is “in a pinch”
cerebral blood flow is closely coupled to_____. The brain normally extracts 50% of O2 and 10% of glucose from the blood, so if:
local cerebral metabolic needs; CSF goes down, the extraction of O2 and glucose goes up: flow metabolic coupling
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:
changes in intravascular pressure, and respond to vasoactive mediators
brain maintains a constant_____ despite fluctuations in ____, and this is done by ______
CPP/MAP; varrying the caliber of the pial arterioles (autoregulation)
on the autoregulation chart, the x axis is: and the y axis is______. Flow metabolic coupling:
cerebral perfusion pressure (CPP), cerebral blood flow, o2 extraction increases to maintain the level needed
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:
autoreglate at higher temperatures; hypotensive for the patient
autoregulation works well between ____, and outside this level, your CBF will ______. So if your cerebral perfusion pressure is low_____
60-150, vary directly with your perfusion pressure, CBF will be low
people with hypertension will have autoregulation that is___, and people with a brain injury will have _____. loss of autoregulation can be____.
shifted to the right. loss of autoregulation. focal or global in brain injury
loss of autoregulation is due to:
pial vessels not doing what they’re supposed to be doing