Test 2 neurophysiology Flashcards
Study back of papers
ok
what are the ideal properties of LA*
non irritating to tissue no irreversible change low systemic toxicity effective topically and injection rapid onset long duration non allergenic stable in solution sterilizable
toxicity
harmful effect of a drug, unwanted, sometimes extension of theraputic effect, overdose, side effect
impulse
a message an action potential, travels from one area of body to another via nerve
stimulus
change in environment that alters balance of permeability of nerve cell membrane
what kinds of stimulus are there
chemical
thermal
mechanical
electrical
threshold
amt of stimulus necessary to initate an impulse
efferent
motor
afferent
sensory- in
what constitutes the greatest anatomic barriers to diffusion in a peripheral nerve
perinurium and perilemma
what are the mantle fibers
they are the first to numb and the first to un numb
what are core fibers
in IA how antereiors get numb
what is the resting potential
-70 mV means it is polarized
what is depolarized
+40
what is repolarization
40 to -70
What is the proposed mechanism of action of LA
displacement of calcium ions from the sodium receptor site
what is the lack of development of a propagated action potential
conduction blockade
what is the sodium pump AKA
ATP gates
what is the pH of a nerve ALWAYS
7.4
where does the acidity change
around a nerve
the higher a pKa number the ______ the onset
slower
the slower an anesthetic takes to work the slower it takes to
become un numb
what receives stimulus in a nerve
dendrite
what is subthreshold
when it reaches -65 mv… light stimulus but nothing happened
what is threshold
-60 mv.. voltage gates opened,depolarization
how quickly does polarization to depolarization to repolarization happen
1 millisecond. .001, thousandth of a second
when Na makes the inside of the nerve -60 what has been reached
action potential
what opens when action potential has been reached
na starts to flood in faster than k can get out
what is sodium equilibrium
+40
what doesnt lose its strength along the way
action potential/impulse propagation
what is the only channel in a cell that requires energy to work
ATP channels
the _______ the nerve the faster the impulse is sent
larger
_____ cant get inside the nerve only ________
RNH
RN
When RN gets inside of nerve it turns into
RNH
what does RNH have a high propensity for
Calcium
What controls the gates
Calcium
What does RNH do
kicks calcium off of gates, turns them off, which means there is no action potential
