Neuro Quizlet Flashcards
Brain usually consumes _ % of total body O2, and _mL/100g/min is the normal CMRO2 ( ~ _ mL/min)
20%
3.8mL/100g/min
~ 50mL/min
CMRO2 is greatest in _ matter of the cerebral cortex at _ mL/100g/min
gray
80mL/100g/min
2 areas of the brain most sensitive to hypoxic injury of the brain:
-hippocampus
-cerebellum
Primary source of energy for neuronal cells and how much is consumed:
glucose
5mg/100g/min
T/F Most glucose in the brain is metabolized anaerobically
false
aerobic
Normal CBF
-mL/100g/min
-total mL/min
-%CO
50mL/100g/min
750mL/min
15-20% CO
Regional CBF parallels metabolic activity and can vary from _ to _ mL/100g/min
10-300mL/100g/min
Gray matter receives _ mL/100g/min of CBF and white matter receives _mL/100g/min
gray: 80mL/100g/min
white: 20mL/100g/min
Which CBF will you see EEG slowing, flattening, and irreversible damage?
slowing: 20-25mL/100g/min
flattening: 15-20mL/100g/min
damage: <10-15mL/100g/min
Transcranial doppler measures the _ CBF in the _ artery
velocity
MCA
Normal CBF velocity on transcranial doppler:
-what does it mean if number is high?
55mm/sec
>120 can mean vasospasm
Which artery has a higher velocity flow when measured with a transcranial doppler, MCA or ICA?
MCA (3x)
Does infrared spectroscopy reflect cerebral arterial or cerebral venous O2 sat?
venous
Which receives more CBF, cortical or subcortical region of the brain?
cortical
5 determinants of CBF:
-CMRO2
-CPP
-Venous pressure
-PaCO2
-PaO2
Is more CMRO2 used for electrical or cellular integrity?
Electrical
Brain autoregulates between CPP of _ - _ and a MAP of _ - _
CPP 50-150
MAP 60-160
What happens below the lower limit of cerebral autoregulation? Above the upper limit?
Below lower limit: vessels become maximally dilated and risk hypoperfusion and ischemia
Above upper limit: vessels are maximally constricted and risk cerebral edema and hemorrhage
CMRO2 drops by _ % for every 1*C drop in temperature.
7%
EEG suspension occurs at _ - _ *C
18-20
Hyperthermia beyond _ *C destroys neurons and denatures proteins
42*C
What controls cerebral vascular resistance?
pH of CSF around the arterioles
_ has a linear relationship with CBF
PaCO2
At a PaCO2 of 40, CBF is _ mL/100g/min. For every _ mm increase or decrease in PaCO2, CBF will increase/decrease by _ mL/100g/min
50mL/100g/min
1-2mL/100g/min