Hello can you hear me
Should have said there was a lot of everyone
So at this point it looks like actually
Welcome thank you for having a good night so far and I told you
It's Tuesday
You're right that was that was Lynyrd Skynyrd Tuesday's Gone Tuesday night gone for me may be gone for some of you but it's not gone for
Morphology is fabulous let's see what we boated here
Rolex and I will put together
And it will take a little time for that download download everything will be good because we are in a book
Taco Tuesday
Alright
And it will take a little time
One Step 1 is not about being Cardiology Cardiology exam
Divisions
What you want to do I would approach on Step 1 is actually would apply to step to some degree but first we're going to go very
With limited to what we want to do is the first thing we do is we qualitatively look at this and say is there a steady rhythm
Fear of them are these are waves about the same distance apart
Alright so you could say the same for them
Do you see them
Bounce across pretty close you can taste
The RR interval the faster the rate
300 150 175 5300 very quick
375 boxes one second one second
317 x 52
Qualitatively examine the waves look like
If I wanted to
That you're most likely to see they're going to involve most of the time alterations in the pr animal so I can do Rhythm and right
Event qualitatively examine the waves to make sure I can see him
And then jump right in and quantitative the PR interval
What I'm going to do is a blow-up of that area
Each little box is .04
Each big box at heavy line is .2
Normal PR interval is .12
Tulip
Which means which means three to five little boxes three to five little boxes
That's what we're looking for 325
So I start here I got one two three and a half
Proximately so it's normal if it's between three and five little boxes that's a normal PR interval
Three little boxes is 120 milliseconds five little boxes is 200 milliseconds you just start at the start of the p-wave
Dr 10123
The first between three and five minutes
Here's the start of the p-wave
Discount the boxes
1
2
Three and a little more so it's between three and five we're good
Again between 3 and 5 boxes is a normal PR interval
So that's the next step I would do
Because a lot of these are really is going to show up related to the PR interval you will see
So I guess quality we determine Rhythm is a steady Rhythm if so calculate the rate
Then do you find Peter St Peter St and do they look okay
And then I want to take the PR interval
This basic steps actually very good at all in kgs even have you progressed past step one for Step 1 this should work that should work
I'm saying that it starts on this line and the other way this starting half
Parks in this box
God starts here where my arrow is so one two three and a half
Okay starts with the p that's what the girls for we start
At the start of the p-wave
Right now the other thing you want to do is look at me and electrical axis
I mean electrical axis
Now this is another one where you can get very precise but you won't need to unstop one we're going to do a shortcut
We're going to do what's called the quadrant method
This is a shortcut to tell us if the mean electrical axis is normal Electro electrical axis is the net direction of ventricular
Zombie QRS complex
Complex
Always remember this is imagine that it's on my chest you're looking at it on my chest
This is left
This is my right
Can a normal range for mean electrical axis is minus 32
Shortcut not going to go through all the physics of it but trust me the physics work out the physics workout
We're going to take to delete
We're going to take the leap one which is your horizontal lead
Lead one is your horizontal lead with the Positive end of the terminal on your left arm
Where they're going to take a BF
ATF goes to the foot
So it's your vertical leap to notice what we're doing well
Miracle League
And by doing this by looking at least we can determine what quadrant mean electrical axis is in
Here's the setup
If the mean electrical axis shows up here that's normal if it does he remember you're looking at me so it's my left side
Deviation
If it's over here then we have a right Axis deviation
Left axis write a Texas
Now how are we going to determine this so all we have to do is determine the net deflection
In the QRS complex for Lead 1 and AVL gauge Lead 1 and AVL
I would get I would if you get any Kg on the earth your exam I would determine the mean electrical axis absolutely
Alright so we're just going to look at least one where I look at 8
Cutting through we're cutting through
All the physics behind it alright to what we're going to do is qualitatively determine if the QRS is net positive not negative
Deflection I'm about to go to that new shoes okay
Show you a picture it's not in your book but I just want you to look at it
And when I say that deflection you consider the up -
-
If it is more than that it's positive
If there is more than enough negative if they're the same then there's no way I'm going to show you pictures and I want you to tell me
Alright I want you to tell me is the net deflection positive negative or no net change
Here we go
Here's the QRS complex
We find the Jeep YJ point is right here
Do you have more going up or going down or is up and down the same
Do you have more going up positive negative
Somebody that is more going up a problem just looking at your ass
Positive reflection and I know this is so from this point I look at how much
This has more than two going up less than one going down there
What's this
I have a lot more going down the going up
So this is a net negative deflection and then negative deflection
What's this
Good there's no difference the amount of going up in the mail going down of the same so no nap deflection this is isoelectronic
Okay so all you're doing is looking at the QRS complex
All you're doing is looking at the QRS complex into leaves
Leave one horizontal vs vertical
So now let's put it in
If a BF is positive lead one is positive then the mean electrical axis is between 0 and 90 which means
It's normal stop and look at it
If f is positive which one is positive then the main axis is between 0 and 90 in other words in this quadrant is quadrant
Is normal
So we have a normal mean electrical axis
I'll stop and let you do that make sure you're following
Goodbye passing all the physics
ABF his foot it's your vertical axis ABF augmented Lead Foot
What is horizontal
If one is positive
My chest
My left side left axis deviation it's over here
How good can eat what causes left axis deviation
Enlarged left ventricle hypertrophy or dilation of it
Left ventricular conduction defects except for posterior bundle branch
Right side and the right ventricle dialing so that's going to drive the main access to the left side what are the big ones too
Will be enlargement of the left ventricle enlargement of the left ventricle through either hypertrophy or dilation
So again
Leave one positive lead Avia negative you're in this quadrant which corresponds to left axis deviation posterior bundle branch
How do you say
URS determine the fraction
If they're both positive you have a normal axis
If any of his negatives and leave one is positive you're over here
Correct current Direction has moved
And again the big ones look for on step will be left ventricular either I purchase for your dilation
All right now
Is positive and one is negative
In the meantime this is between 90 and 180 which means in this quadrant
That is a right Axis deviation
This year we are looking at
Anteflexion and 80th for the QRS and the net deflection in Lead 1
So that's what we're looking at that you determine is it net positive or negative
Yes baby I'm positive notice on the figure it's got a positive here in the negative Lead 1
ATF is part of the lead on the EKG you better have 12 leads on the EKG 1 2 & 3 AV Lab Rats
And then you have six precordial
Just one negative a positive
Squadron right Axis deviation
If they're both negative
Causation
Right ventricular conduction defects or the posterior left bundle branch remember those left axis deviation
Remember
Go pull it to the left
When you get a conduction block it takes time for the for the current to go through okay it takes time for the current to go
4 round
So what that does to slow it down and it pulls the electrical component that was called a Defector
Okay and that direction
So I am really come by passing without going into great great detail that's the best I can do I can go into great detail but it take
You take way too long and it won't be hurt you whatsoever for Step 1
But bottom line you're changing how rapidly things conduct that changes to the electrical current
And that's what causes a deviation
When a BF and leave one or both negative then you still have a right Axis deviation you're over here so no that's something
You have a negative negative lead one you're going to get a right Axis deviation and I wouldn't worry about extreme right Axis
My taxes I would even worry about it I wouldn't even worry about it
Not for Step 1
So again are you doing at the fox
Cause of extreme ride would be some significant conduction defect is the most likely but again I wouldn't worry about it
Where is it right Axis deviation or not they might get hit with cor pulmonale with extreme I purchase of the right ventricle
But all of these are going to shift to the right so if you have a negative lead when you have a right Axis deviation
Okay give an example of your absolutely right ventricular failure pulmonary hypertension that causes hypertrophy yeah absolutely
Hey if the way there's no net no not depends on which one you're talking about
If there's no no deflection then the main axis is 90 degrees
That's a good one has known that I look at a vehicle if it's positive that I'm right here at 90 degrees
Still normal still normal
If a BF is negative then I'm up here I still have left axis deviation
Gay
This is a quick quick quick method very quick
And all you're doing is looking at least one on a 12-lead EKG
We don't have any we don't have any 12 lead EKG examples in the book
That's why I gave you those basic that's all you do is find lead 180th and look at the net that we went through
Just want you to know whether or not there's an axis deviation so another words they make clothing in the clinical vignette
Until they say a patient that has a right Axis deviation on the EKG and you go right Axis deviation that's over here
What could cause that well whatever could cause hypertrophy of the right ventricle like a pulmonary embolism or pulmonary
Cor pulmonale all those kinds of things
But that's just too cute that's just too cute or they may give you an EKG where you're looking at you know this patient looks like
Heart failure
They give you a 12-lead EKG and you see right Axis deviation then you know it's right heart failure not left heart failure
That's how they're going to play it that's going to be kind of the clinical vignette scenarios
So that's why I would if they give you a 12-lead EKG
Real quick looking one look at ADF bingo
They may give you a question about axis deviation absolutely I can just say
Excellent excellent let's go to some basic arrhythmias if you're going to see it was on Step 1 these are Far and Away the most like
Good clearly these are all the reviews that exist
But again this is not super high yield for Step 1 basic very basic Step 2
Maybe
What we're studying for Step 1 right now we're not worried about that
The first let's go through all the heart blocks here's an example of first degree heart block to see a steady rhythm
Very good we have a steady wear them so we determine the rate
Here we go 300 150-175 almost 60 the next R wave is just a little before the box so heart rate is normal it's between 60 and a half
Is between 60 and 100
To have a steady rhythm
Have a great next step to ICP Taurus
PUSD PUSD Next Step The Next Step
What's the next step what are you jump to next PR exactly
The price that PR interval
Start of the P wave
The QRS complex
In this example is 8 boxes of boxes
It's much greater than 325
What's greater this is by definition first degree heart block
First degree heart block is elongation of the PR interval the pr intervals greater than one big box
This is first degree heart block
Patient doesn't have bradycardia heart rate is normal it's just a little above 60 have a normal heart rate
We have a normal heart rate
But we have an elongated PR interval we are having problems connecting to the AV node
We are having problems connecting to the AV node
Could be damaged
To be Mia for example for example
All right now your book is wrong so please correct it this figure should say second degree heart block
Write second degree heart block
Calcium channel blockers and beta-blockers
Exaggerator first-degree block
Because they're going to slow conduction through the AV node
Nice question to you
Alright please correct your boat 2nd degree heart block
First thing we do you see a steady rhythm
You see a steady rhythm
No one steady Rhythm so one of the things to think about with an unsteady Rhythm is a second degree heart block
Monkey Bar this is an example of Winky Bock have an unsteady rhythm
UIC sdn do we jump to next
Where do we jump to next after we've qualitatively look PR interval okay let's start with this one there's a PR interval
It's getting longer getting longer getting longer wait a minute there's a piece and no QRS interval comes back while looking at
PR interval
Any longer getting longer P wave no cure
That is mobitz type 1 Wiki bark there is a progressive prolongation of the PR interval and tell him ventricular be dismissed
Sex again
Here we go
This is the definition of second degree heart block
Every QRS is preceded by
Not every P wave is followed by a QRS
Gave notice
Every QRS is preceded by a
Not everything is followed by a QRS that is the definition of second degree heart block
We have two types mobitz 1 mobitz 2 but which one is winky Bock winky Bock is a progressive prolongation of the PR interval
Till we drop the beat
And then it starts over that's why he bought so I'm steady Rhythm while the first arrhythmias that should go into your head thank you bye
Winky bock
Now let me ask you this you member I said last night
I said where's atrial repolarization where is atrial repolarization and you told me it was buried in the QRS right you said
Ridiculous
There's a way there's no cure it.
Do you see atrial repolarization
Here's the P wave no computer
Do you see atrial repolarization polarization see the EKG doesn't pick it up the EKG doesn't pick it up
Haha I told you I would prove it to you told you I would prove it to you but then you're going to go well you know I'm still not
Not convinced I'm going to do on the next slide but first
What you need to do at the break or after the lecture is over is go to YouTube and search for diagnosis wenckebach you will love
You will love it I promise I promise
Here's a real EKG real person winky bock
P wave no QRS
Do you see atrial repolarization
P wave Nokia
Repolarization
You can pick it up pick it up you can pick up tons of hearts
And there's no Rachel repolarization
Gay
You don't pronounce winky bock
That's how everybody I've ever talked to
This would be a negative deflection of the QRS complex
Not in German you would say
Correct now
No no no
Second degree heart block type 2
Rules are rules every QRS appreciated but not every P wave QRS
Okay going to distinguish which two and we talk
RCP Block
Exactly
Do when you have a PR interval
It will be the same
Winky Bock winky Bock changing that's how you distinguish all right now it's time to could be study could be on stage just to pin
Can go with that okay you can go with steady and unsteady for mobitz type 2
Could Be steady could be unsteady
How we distinguish them
Is the PR interval when it exists
It will be the same as mobitz type 2 it will not be the same in week about
See you where we're going to that PR interval you see where we're going for that PR interval that's two step
Alright
Number of peas you just look to see if the pain is pretty much the same
370
Don't spend time trying to label
Get it get it
Confirm
You're spending so much time trying to figure out exactly where every two minutes on this question but you don't want to do
Define just look for steady Rhythm that slow I do not see a locked PR interval 30 degree heart block thing that's the answer
That's the answer move on
Gay
That's your answer
33 hard to move on you're not spending all that
Alright just finish and then take a break don't worry about
First thing we do
Okay so we exclude exclude winky bock
Next I determine the right 360 quality look at the waves
Look pretty similar
Looks like a saw
This is a very very coordinated conduction
So that's why we see these waves in between his coordinated very fast almost always always have them
Waves
What's up with that
No coordination
In between the QRS and T
We can't there's no pattern whatsoever I can find a pho so 1 steady Rhythm winky Bock know it's too maybe even a thin
I like it I like a 5784 I wouldn't be surprised if you get an EKG A-fib a flutter yeah yeah I like that I like that
Gay
There's no coordinated conduction that's why we don't have anything resembling a p-wave
Atrial flutter is almost almost a hundred percent of the time study with you have to appreciate on an EKG
It's really difficult to say a hundred percent
Okay but I wouldn't look for that you know if you hear hoofbeats horses so atrial flutter going to be studying step one it's going to be
Cuz it's almost always daddy almost always
So rare that it's not
The last one is called wolf Parkinson White
Wolff Parkinson White disease except
322 The ventricle
Okay
Which one are you referring to exactly
This one is they feel unsteady Rhythm can't find the P wave a fee
I'm steady Rhythm can find a p-wave a fan
Next question just move on you got it wrong
Wpw ECG rhythm
Do you see a steady rhythm
Determine the rate 300 150-175 okay okay okay right
Do you see pqrst pqrst
St Peter St Peter St
Okay well that's good what's next
What's the next thing
Prr exactly
What's this isn't the best example because this is about three black boxes so it's on the short end but the other distinguishing
Is notice we get this slow enough you know normally the P wave goes and then flat and then are this is the delta-wave this is a beauty
Beltway right there that's a Delta wave this is wpw short PR interval and that Delta wave wpw accessory pathway for me.
Short PR intervals telling you you don't have no delay in PR interval
All about AV node delay here with bypassing it or bypassing the AV node
Right here this right you know the P wave ends and then it starts Rising you start seeing away from the r-wave
Again the P wave normally after the end of the play we have a
Then it shoots up here the end of the p-wave it start
Blue marlin that's the delta-wave
And you're concerned about this arrhythmia taking if they go into a tachycardia
Alright for the very last part then we'll take a break will end up the EKG and take a break
Here are some high-heeled things to look
WorkOne related related to changes in the EKG OK some paths form integration 1 ST segment elevation
Think think
Transmural infarction
And means across the wall
And prinzmetal angina
Which is corn a face spasms this is really important for pharmacology folks right here
This is prinzmetal angina so you think this is spasm
If the ST segment gets depressed
Give it to Manti Utah
Antidepressant agents
Valium something like that it's really depressed it said it's okay sorry
This is a sub into car dealers classic sometimes called exertional sometimes called stable angina
And this again is very high yield for pharmacology
All right now potassium calcium very important
Hyperkalemia will increase the rate of repolarization hyperkalemia will increase the rate of repolarization you needed this real quick
How do I get rid of the presents you give me the prices to the SD yes he is really depressed yes he is depressed to see how depressed you
So you got any depressants
The gym
Hyperkalemia increases the rate of repolarization that's the T wave
Super sharp spiked T waves that suggest hyperkalemia
This would decrease the QT interval because I'm repolarizing faster
Right now what we talked about for potassium and calcium in nerves doesn't apply to the heart so don't try to figure out
See how this works
You just gotta roll with it is one of those you just have to roll with this is changing potassium Channel function
Now I'm going the other direction hypokalemia typer increase it will decrease it and we can generate what are called you
Which are secondary waves after the T wave
Alright secondary waves after the T waves
So you get U waves and hypokalemia if I'm delaying repolarization in the QT interval gets longer
The QT interval gets longer
Alright remind me of the antiarrhythmics are going to have the same effect
Antiarrhythmics again
Affect
Class give me the classes because very good one day
And class 3 good class 3 anti-arrhythmic
Ten channel blockers Smurf drug sotalol
And also the one the one okay that's quinidine and procainamide why do we care about a Long QT
Why do we care about a Long QT you don't have the pictures I'm just showing you the pictures I'm just putting the text on the picture
I'm just text the Texas right there I'm just follow right along with the text beautiful you worried about this one torsades
This potentially fatal arrhythmia torsades very high yield for step one right here Long QT increases possibility of torso
Very high heels very high heels I'm just drawn this picture to show you but the text is right there just following the text
And then little right here is one of the greats in for reminding remind me
We understood Moses
Linda genetic sodium channels that don't activate that's what we talked about last night Miguel very good very good
Treat with magnesium you're right
Alright last is calcium
Calciums going to work just like the potassium if I have too much calcium decrease QT interval if I have too little calcium ion
Just like potassium hyperkalemia hypokalemia again do not do not try to apply what we talked with the nurse this is different
Different and what I would look for all these is it written in the clinical vignette
What do you mean the books
Thank you for pointing that out we gotta fix that
Is it wrong it wrong
I will take a break there when we come back we'll do a little assessment and move onto skeletal muscle it will take about there
Thank you for pointing out the error
Let me rephrase that let me rephrase that point out 20 out the error error okay who did this who had this
Imani Imani yeah good good
Mommy's got to get a cookie for that
Alright we'll take a break
Okay we are back
Imani Imani I hope I'm saying
Close enough I'm sorry I'm doing the best I can
Don't say I'll bring you a cookie
Let you down I would let you down
Well good I like it when we're energized there we go what we're going to do before we go to the next chapter
Good cookies
We're all energized the question
Calcium and sodium is the ones
Could increase the current
Alright alright
Structure of a skeletal muscle fiber is the cell for a skeletal muscle is composed of all of these sarcomeres still here still
Unit the sarcomere where is the sarcomere
I wouldn't get too bogged down on H Zone a band I band excetera
I don't think they're really going to press you on that on step exam but you do need to pay attention to is the idea that
Where is the functional unit of the sarcomere is the functional unit
And then that's sarcomere this portion we're going to have actin filaments that's here myosin filaments is here and then work
Another protein called Titan titans going to be important because it holds onto myosin
Hold on to myosin
Part of the elasticity
Yeah we're about to go into a love story this is a love story I'll show you in just a moment but he recovered just a spectator
Unit one actin myosin typing
Now
Remember that the cell membrane is called a sarcolemma sarcolemma for muscle so there is your mom Fireballs within the circle
The T tubules is just an extension of the sarcolemma it will dive down there and this will be important because it will carry the app
Take care of the action potential from the sarcolemma down into these myofibrils
And last but not least the terminal cisternae this is of the SR sarcoplasmic reticulum its stores calcium
It's store
Five basic proteins that we need to know for Step 1 and it turns out it's a love story love stories I hope you like the love store
Like love stories are we good with love stories are they okay because you know we get a little sappy it's okay it's okay it's love
No no love stories at all no way no okay okay
This is the kingdom of striated muscle
The kingdom of striated muscle so this would apply to cardiac and skeletal we're really just referring to skeletal but it's actually
Striated muscle in his kingdom of course we have the beautiful princess named acting she is so pretty very beautiful
And she's in love with a handsome young prince name is here's my sis is the myosin head actin and myosin really really really love
I mean they love each other
Turns out that acted as a binding site for myosin
We're trying to do the G-rated version
Okay I'll go back
T
Is acting as a binding site for myosin binding site don't get dirty don't get dirty don't get dirty
We don't see anybody inside here
Finding each other
Because
Tropomyosin is the king of the land and who is his daughter well it's acting acting is his daughter so you know you're not going to know
Triple Madison keeps actin and myosin Park
Keeps them apart covers up The Binding site and says you're not good enough for you stay away
Queen troponin
Troponin
What's around is going to
Is the jilted Lover of My Soul
Beautiful in the whole time the whole time
Go to your feet
But I know this is hard to believe
With me with me
Because
Triple A
Stay away from my daughter stay away from my daughter got it prevents the interaction
When calcium prices in the cytosol well thank
And look at another two lovers so what do they do
Hug hug
G-rated
And it's a very forceful hug I mean my sins in a high-energy state
His love of his life he grabs his acting and Hozier
You know which of course is referred to as the power stroke but it's just a hug is just a hug
Guy pulling his acting generates Force that's called the power stroke that's what generates force in muscle this binding effect
Simply generates Force generates Force
Take this picture of the medicine that I'm sending this picture but I just reminded you tighten sagging on the bus
She is no dummy dummy
Because he's called ATP and what is ATP it goes It goes pushes them apart
You can put away
What does Niacin do
Which put into a high-energy State email
Any pools in ATP comes and Associates
That generates active in this process just keeps going provided we have plenty of calcium is the key and it's troponin
Thrift think about something for a second think about something for a second associate actin and myosin dissociate actin and myosin
Now
The quicker the quicker myosin can split a teepee the quicker you can get back to his love you very
Think about that
The faster myosin can
The quicker he gets back to his love
So the faster the ATP Ace activity the faster we rebound and the faster we talked we talked Acton
So I will talk about in just a little bit the velocity of directly related to the
Number 2
Hug for a very long time
When do you not have ATP
Because these to dissociate acting very very similar
Dr.
I'm sure you told you told you yes but they won't release lactic acid and that's one of the Hallmark traits of mcardle's
So the clinical vignette on this exam week stress test just contracted muscle and they develop contractures and it's noted that venous blood
You have an elevated lactic acid Cardinals
Physiologic contracture with no lactic acid Bingo mcardle's that's in mcardle's patients a little quick biochemistry integration with
Without dr. Turco
It reminds us of dr. Turk
What an awesome what an awesome instructor
All right once we get calcium back to a low-level trouble by
Tropomyosin gets back in the way they jump on my ass and gets back in the way
The patient doesn't have to be very young I mean you make diagnosis when they're young but you can live there are patients with me
Are certainly in the adult phase certainly the adults they don't have to be very young although that's probably when you're going to do
Yeah they can get muscle injury so they may get a little myoglobin in the urine doctor
Sounds good to me he's about chemistry Guru
But it makes sense
Hey if I'm getting contractions if I can make it
Clearly I can see music because it goes back down compromising comes back and gets in the way no more interaction for our
Two young lovers
Calcium is the key next step for Step 1 is that we need to know is what regulates calcium
Well that's on the sly
Alright good to hear that to hear the two keys to 2
Receptors and we need to think about that one is the Hydra pyridine
He is resting skeletal muscle dihydropyridine
The Hydra pyridine is
Remembering my dear it's on the membrane of the skeletal muscle cell
So it's associated with the sarcolemma
Technically the HP or voltage-gated calcium
Calcium channel
Technically technically okay however calcium does not flux through the channel in skeletal muscle it will in cardiac it will end soon
But it doesn't in skeletal
So what you doing in skeletal it's acting as a voltage sensor
Hey it's acting as a voltage sensor
Cuz it's a voltage-gated channel
II receptor is right here or why are Ryan Daddy
Ryan Daddy
Everest
Hydro pyridine is going to
Brian D
Sonos PHP part of the sarcolemma
Fits into the rioting Channel ryanodine receptor Ryan any news on the sarcoplasmic reticulum
It's a calcium channel on the sarcoplasmic reticulum so the two big things for calcium skeletal muscle Hydra.
Plumber
Sensor
Diana Dean calcium channel on the Sr
Now look at the picture the picture remind you
You have a lot of calcium inside the SR so you have a big gradient for calcium come out of the SR into the cytosol why doesn't it
Because BHP blocks the Ryan
Dhp blocks and here's the way to think of it there's way to think of it look at it it's like a cork
In a champagne bottle
Or wine bottle BHP at rest is cooking it's working
The random Channel
Hey it's corking the right idea Channel
Everest
So therefore calcium doesn't come out through right now because it can't it is physically blocked
Sewing skeletal muscle dhp physically blocks the Rye ending it works it so we're sitting right there in a quart
What happens when we initiate an action potential
What receptor on to what receptor
Phil Collins acting on what receptor
Nicotinic muscle very good nicotinic muscle produces an EPT you're right Maria very good
Generate an action potential but it's a nicotinic on the muscle very good non-selective
2000 channel so we generate an action potential this gets carried down the sarcolemma membrane by the fast sodium channels
Knives down into the cell via the T tubules
What channels carry the action discussed last night
Speed sensor
Which sentence is change in potential
Change in potential and what happens here is the action potential coming down it causes the HP to change
Ensure and Uncorked in Uncorked Bryan today so it's just like taking and gone
Some of the action potential pop the cork for Ryan today
When we pop the cork for Ryan and Kelsey was going to move down its electric chemical gradient we're going to flood
Cytosol with calcium
Now notice we pop the cork
Is calcium the comes out will open other Ryan adding channels
This is calcium induced calcium release
So calcium in during the cytosol opens other entities which will cause more calcium released so calcium induced calcium
Peace
Member we mention that last night with cardiac muscle have the exact same thing here at the exact same thing here but what's different
Calcium is coming from the Sr
Calcium
Binds to troponin a King Edward crossword cycling active tension
So that's how we can regulate calcium in the action potential
Incense by BHP it on chords Ryan Adams
Some of the excess calcium opens otherwise any calcium induced calcium release
The calcium binds to troponin C this causes crossword cycling that's muscle contraction active tension
All right now
This is called Circa
Circa is a calcium ATP a step pumps calcium back into the Sr
And once we pumpin of calcium back into the Sr
No more hate you
Tropomyosin goes back and you get relaxation
So what drives relaxation Circa activity Circa activity Circa is responsible for relaxation
Crack Monica calcium released from the SR triggers more calcium released from the SR by opening Randy that's calcium induced calcium
Circa pumps the calcium back yet that's how we get relaxation
Y******
We got a contraction one side of Salt Lake County
Once we put it all back in you get relaxation it's all related to calcium
Circa is an ATP is it pumps calcium against its electrochemical gradient
It's a pump basically a pump
Not all calcium for contraction of skeletal muscle comes from the Sr
Calcium for skeletal muscle contraction comes from the SR we're not we're not moving in from the extracellular compartment
I'm coming from the store
Nosara solid calcium is responsible for contraction in skeletal muscle you do not need side of Salt Lake County
For the mechanical effects of calcium affect the nerves
But you don't need it you don't need it it's different for smooth and cardiac you're absolutely right and we'll mention of it
When you pop it back in then go yes
Voltage-gated sodium
Carrying the action potential just like in a nerve
They are responsible for the action potential
Muscle relaxers work on Circa not to my knowledge
Most of those work centrally to all turn around I'll put most but I don't know tons about those
We can have questions from like this as well give up we'll do some assessments at the end but you know we can frame questions in a row
Reminding ourselves of Circa so let's say somebody can't relax very easily so he got a patient may fail to show normal muscular
Creation
The problem is defined in the muscle itself you should be looking for circa Circa as your answer
Right there two ATP is involved in the myosin ATP Ace we already discussed cross Bridge cycling and Circa and Circa
Circus themes for smooth endoplasmic reticulum calcium dependent a TPS or something like that during that in your book it's such a long
So I have to look it up because it's a pain
But the actual word is in the book
Sarcoplasmic in the number 760
ADHD defect would not cause a problem with
Relaxation
Okay so those are steps again closed
Cork we record an action potential and corks
Calcium channel blockers do not affect skeletal muscle
That's why the Hydra.
Ozone affect skeletal muscle because no calcium is going in no calciums going in through here Miguel
Okay they do affect smooth and cardiac but not here because calciums not flexing calcium is not flexible path Farm integration
Hyperthermia
Malignant hyperthermia is the opening of ryanodine receptor stimulation and Aesthetics like how the thing but also sucks in Elko
You get hyperthermia because you're driving cross Bridge cycling these are staying open calciums around our lovers get the hug
Hug hug hug and break and hug and you generate heat hence the hyperthermia
If you beat me to it and you treat with
You treat with dantrolene why do we treat with dantrolene because it blocks
Ryan Adams blocks Ridin Dirty
Why don't you just use rocuronium
I mean it's such a cool drugs such a cool name why don't we just call it rock your world why don't we just do some rocuronium
Too much hugging your ride hyperthermia for too much hugging
Why don't you just use rocuronium work work
Because you're right it's blocking up here
Is not going to do anything to this because we have a direct opening of these by these compounds
The Rocky Mountains not going to help we have to do something at the site which is Randy receptor that's why dantrolene is working
Okay actually I will take a break there when we come back
We'll talk about how we can change force in skeletal muscle