10/04 Flashcards
what is the space on the skeletal muscle called where the neuron comes in close contact with the skeletal muscle, Where ACh should be concentrated
junctional
if we look outside of the junctional area, what is this area called?
peri junctional
What is the area called that is placed past the peri junctional area?
post junctional
What areas regarding an normal nACh synapses should be affected with succs?
junctional
maybe peri junctional
in a normal synapse with ACh, which area should be able to repolarize easily after being given succs?
the post junctional area
how can we keep tabs on how well our paralytics are working?
neuromuscular monitoring
place electrodes on a nerve and run current through them. This should generate an action potential and cause contraction of nearby muscles
what is the physiology of using an electrical current to stimulate a contraction?
the inside of the cell is negative and outside is positive in a normal resting neuron.
We have one cathode and one anode. We send electrons (negative charge) on the outside of the cell from one electrode to the other thereby making the outside of the cell more negative.
When the outside and inside of the cell are both negative, there is no polarity between them and so that depolarizes it.
fast sodium channels are triggered
no polarity from the outside of the cell and inside of the cell means that it is
depolarized
when we start looking at EKGs, we will start looking at the current that runs
outside of the heart
What is the voltage called that creates a strong enough depolarization that it should not have a hard time generating action potentials in all the underlying neurons?
supramaximal stimuli
why do we use supramaximal stimuli?
Because it gives us a good baseline
what are some of the settings that can be dialed into the electrodes to produce a muscle contraction?
single twitch
TOF
Tetanic
*post-tetanic count (PTC)
Double -burst stimulation (DBS)
What is the frequency that TOF uses?
2Hz/2S
2 impulses over 1 second for a total of 4 impulses over 2 seconds
Which type of block creates a pattern of the first twitch being stronger than the following twitches?
an incomplete non-depolarizing block
Which type of block creates a pattern of the all of the twitches being equal but not at baseline?
incomplete depolarizing block
what is a post-tetanic count?
a measure of the health of the synapse after a tetanic impulse.
is it ready to go after it’s fired 100 AP?
what is a double burst stimulation?
when you use tetany in short succession
what muscle group does the ulnar nerve innervate?
the adductor pollicis
what happens when you stimulate the adductor pollicis?
the thumb will move towards the palm
and/or
the pinkie will move toward the palm
What are the electrodes that are placed on the side of the palm and pinkie?
sensory electrodes that measure and graph the reaction of the muscle
what are other places than the adductor pollicis that you can monitor your neuromuscular blockade?
ophthalmic branch of the facial nerve (orbicularis oculi)
peroneal nerve (butt area)
posterior tibial nerve
in a NDMR, onset takes a few minutes to kick in, and then depending on which drug you use, you have different
half lives
minutes to hours
what does NDMR stand for?
non depolarizing muscle relaxant
why is succs very popular?
it’s cheap
-quick onset
-short half life
Succs can be given through which routes?
IM
IV
NDMR’s have a ____ half life
long
What should a base line TOF graph look like?
all of the twitches should be even
the twitches come back in ______ with a NDMR
stages
If we quantify the strength of the twitches of the first and last twitches on a NDMR, we should be able to express this as a ratio. what is this called?
the TOF ratio
what part of the TOF ratio relates to the last twitch?
the numerator
what part of the TOF ratio relates to the first twitch?
the denominator
when the NDMR is first wearing off, you would expect the TOF ratio to be
very small
The TOF ratio tends to _____ when we get closer to baseline
increase
all 4 twitches recover ______ in a depolarizing block
evenly
non-depolarizing and depolarizing drugs work on what two places?
the skeletal muscles and the neuron
What type of ACh receptor is found on the neuron that releases Ach?
an autoreptor called alpha3beta2. It has 3 alpha subunits and 2beta subunits
how many ACh are required to open an ACh autoreceptor?
2, although there is a third spot for ACh to bind it doesn’t require the 3rd to open
where does the ACh come from that activates the autoreceptor?
from the synapse from that neuron
what comes in through an autoreceptor on a neuron? What does it do?
Na+ and Ca++
causes the VP1’s to move down towards the cell wall to replace VP2
A NDMR works on both the _____ and ______
skeletal muscle- blocks EPP
neuron- blocks auto receptor
if we block the auto receptor, we don’t have ________ which makes the subsequent action potential
VP1 converting to VP2
weaker d/t less neurotransmitter being available at the synapse
depolarizing drugs effect the auto receptor by
holding it open and continuously stimulating VP1 to convert to VP2