7 Brain Flashcards
What makes white vs gray matter
White= axons, gray= cell bodies
Pseudounipolar cells: 2, bipolar: 2
Pseudo: drg and cranial ganglion, bi: retina, ear
Astrocyte function
Metabolic reg and neuron repair
Ependymal cell function
Form choroid plexus to make csf, in 3rd and 4th ventricles
Oligodendrocyte function
Form myelin sheath in cns
Microglia function
Phagocytose debris
Brain part where motor and sensory cortex are
Motor: frontal, parietal: sensory
Where in brain you understand vs motor control speech
Understand- wernicke, talk- broca
Cognition, sensation, movement area
Cerebral cortex
Memory and learning area
Hippocampus
Emotion, appetite, response to pain area
Amygdala
Fine motor control area
Basal ganglia
Areas of autonomic reg
Pons and medulla
Cerebellum parts: equilibrium, muscle tone, and voluntary movement
Equil: archeo, muscle tone: paleo, neo: voluntary movement
Only cranial nerve that isn’t in pns, how its also diff
CN II, surrounded by dura
CSF: volume, specific gravity, and pressure
150 ml, 1.002-1.009, 5-15 mmhg
CSF: produced by what/rate
Ependymal cells of choroid plexus, 30 ml/hr
CSF circulation path
L and R lateral ventricles, foramen of Munro, 3rd vent, aqueduct of sylvius, 4th vent, foramen of luschka (2) and foramen of magendie, brain and SC, superior saggital sinus
Where csf is absorbed
Arachnoid villi in superior saggital sinus
Pneumonic for csf flow
Love my 3 silly 4 lorn magpies
CBF equation
CPP/CVR
CBF rough amount in ml or % CO
50 ml/100g/min or 15%
CBF value when: ischemic, cortical suppression, cell death
20, 15, <15
Determinants of CBF: 5
Cmro2, CPP, venous pressure, paco2, pao2
Cmro2 value
3.5 ml/02/100g tissue/min
% of 02 utilization for electrical activity vs cellular integrity
Electrical: 60%, cellular: 40%
How cmro2 decreases with temp, when eeg suppressed
7% per degree c. 18-20 c
At what high point in temp does CBF decrease
42 c
CPP: autoreg range, calculation
50-150 mmhg. MAP - ICP (or CVP if higher)
When happens to vessels when CPP <50 or >150
If less: maximally dilated and risk hypoperfusion. If greater: maximally constricted, pressure dependent, risk hemorrhage/edema
If ICP is elevated, CPP requires what to be maintained
A higher MAP
Autoreg is abolished by what
IC tumor, head trauma, VAs
Conditions that impair venous drainage, ultimate result
Jugular compression from positioning, inc intrathoracic pressure from coughing/peep, VC thrombosis or syndrome. Dec venous drainage and inc CBV
Relationship between Paco2 and CBF
Every 1 mmhg inc in co2 above 40 CBF will inc 1-2 ml/100g tissue/min. Also dec if below.
Max dilation and constriction at what CO2 levels
Dilation: 80-100, constriction: 25
Resp ___ inc CBF, resp ___ dec CBF. What does not affect CBF
Acidosis inc, alkalosis dec. Metabolic acidosis (doesnt cross bbb)
PaO2 < what causes cerebral dilation/inc CBF. If above what no effect
<50-60, above 60
ICP: nml range, when htn, when its measurement is indicated
5-15, 20, if gcs of 7 or lower
S/s of IC htn
HA, NV, papilledema, focal neuro deficit, dec LOC, sz, coma
Components that can inc ICP
Brain, blood, csf
Cushing triad, what it means
Bradycardia, htn, irreg resp. IC htn
Most common site of herniation, inc pressure on what
Temporal uncus, midbrain
Sign of temporal uncus herniation
Comp on cn III —> fixed and dilated pupil
