CNS Flashcards
intracranial HTN cut off
- 40 is severe(ischemia)
signs of elevated ICP
HA/nausea then decreasing consciousness then coma/cushing response and motor posturing
normal ICP
5-10
cerebral auto regulation range
50-150
cerebral steal
vasodilation that occurs in healthy region of brain during period of ischemia. so pulls blood flow from ischemia to healthy brain. so ischemia gets even worse blood flow.
inverse cerebral steal/robin hood
vasoconstriction caused by hyperventilation or drug that causes vasoconstriction in healthy area to have more flow go to ischemia area
how much oxygen and glucose does brain get over needed
3x oxygen and 7x glucose during normal activity
CBF numbers
50mL/100g/min. gray matter is 80, white is 20
CBF per min
750mL/min
CBF ischemia numbers by 100g
20-30 start of neuro symptoms. 15-20 isoelectric EEG, no evoked potentials. 10-15 Na/K pump fail, cytotoxic edema. less than 10 is irreversible damage
CSF volume
124-150mL
CSF production per hour
20-30cc
what makes CSF
choroid plexus ependymal cells
pH of CSF
7.32
IV anesthetics that stand out brain
ketamine up CBF. etomidate can precipitate seizure
worst volatile that causes cerebral vasodilation mor
halothane. best is sevo
volatile that is epileptogenic
enflurane
volatile we use that up CBF
des over 1 MAC
PaCO2 goal for craniotomy
linear relationship between PaCO2 and CBF from 30-60. under 30 no change so keep at 30
how many vertebrae
33
how many spinal nerve pairs
31
which tract crosses in cord
sensory
how to know where autonomic dysreflexia starts
happens w/ injury above T6. flushing above injury(parasympathetic) and vasoconstriction below(sympathetic
collateral spinal blood flow worst where
T1-4
which system has ganglia in the organ
parasympathetic
sympathetic chain in cord location
T1 to L2
what nerves have acetylcholine
all parasympathetic and pre ganglionic sympathetic
a1 receptor job
vascular smooth muscle constriction
a2 receptor job
found on pre synaptic neuron and inhibit release of norepi
b1 receptor job
up contractility and HR. too much can cause arrhythmia
b2 receptor job
vascular and non vascular smooth muscle relaxation
alpha brain wave
Awake-resting
beta brain wave
Busy, thinking
theta waves
GETA. general anesthesia
delta waves
Deep sleeping-general anesthesia
anesthetic agents other than increase latency/decrease amplitude. SSEP
NO latency no change, down amp. etomidate up both. ketamine up amp. opioid and muscle relaxant no changes
type of greatest heat loss during GA
radiation
factors that are synthesized in liver
2, 5, 7, 9, 10, 11 and 12
