The Cholinergic Receptors
Understand the cholinergic receptors once and for all!
The Cholinergic Receptors.
This is a high-yield topic.
You really need to understand this when you're going into your boards or exams.
These receptors are found in the central and peripheral nervous systems, and they use Acetylcholine as their neurotransmitter.
Thus, they can also be referred to as Acetylcholine Receptors, and their abbreviation is ACh for Acetylcholine and R for Receptor.
There are two main types of these Cholinergic Receptors: the Nicotinic Acetylcholine Receptors and the Muscarinic Acetylcholine Receptors.
The Nicotinic Acetylcholine Receptors are named such because they are responsive to both Acetylcholine and Nicotine.
They are ionotropic receptors, meaning that they are ligand-gated ion channels.
When stimulated by their neurotransmitter, they themselves become an ion channel.
The Muscarinic Acetylcholine Receptors, on the other hand, are named such because they are responsive to Acetylcholine and Muscarine.
They are a different kind of receptor.
They're what's called a Metabotropic Receptor, meaning that they act through a second messenger system, which in this case refers to the fact that they are G protein-coupled receptors.
Let's talk about the Nicotinic Cholinergic Receptors first, and this is abbreviated the same as what we've seen, AChR, except now with an "n" in front of it to denote Nicotine.
So the Nicotinic Cholinergic Receptors, they're directly linked to ion gated channels, as I previously said.
There is no second messenger system here.
The receptor is a physical part of the ion channel.
These ion channels are made of five subunits, and they're arranged symmetrically around a central pore through which ions travel when opened.
Also, each of these five subunits is made of four domains, which we might talk about later.
However, it's not necessarily high-yield right now.
When stimulated by either Acetylcholine or, remember, these are Nicotinic Cholinergic Receptors, so either Acetylcholine or Nicotine can stimulate them, there is an initial stimulation, an initial opening, followed by a blockage or a refractory period.
This is important and interesting to talk about because it's related to how some of the drugs work that we will talk about in other lectures.
Let me give you a quick visual example of what is happening when these receptors are stimulated.
I am going to place two molecules of Acetylcholine on the screen and then two separate ions, and these ions can be Sodium, Potassium, Calcium, and so forth.
So what is going to happen is that the Acetylcholine molecules are going to come down and interact with the receptor/ion channel.
This is going to cause a conformational change in the shape of the ion channel, which is going to open the central pore to allow ions through.
Let's take a look.
Kind of interesting, isn't it? Let me repeat this a couple of more times.
Kind of neat how that works, huh? Well, as if we didn't have enough abbreviations to remember, I have to add two more, unfortunately.
There are two sub-types of the Nicotinic Acetylcholine Receptors: the Neuronal-type, abbreviated Nn, and the Muscle-type, abbreviated Nm.
The Neuronal-type is found in both the central and peripheral nervous system, and it is most often found "Up-Stream" in the nervous system, from other receptor types.
So take for example the sympathetic nervous system and the associated Adrenergic Receptors.
For a sig to get through to the Adrenergic Receptors, it must first travel through a Neuronal-type Nicotinic Receptor in an "Up-Stream" ganglion or nerve.
The Muscle-type Nicotinic Receptors are found post synaptically in the Neuromuscular Junctions, and they are responsible for our skeletal muscle contraction.
They are what let us move and breathe consciously.
So keep these two subtypes in mind.
At the end of this lecture, I will give a picture and an example and walk you through where they are.
But for now, let's skip on to the Muscarinic Receptors.
Okay, so the Muscarinic Receptors are a little bit different than the Nicotinic Receptors.
First of all, they're named Muscarinic Receptors because they are responsive to Acetylcholine and Muscarine.
Also, they use a second messenger system to propagate the signal.
In this case, it's the G protein-coupled receptors.
I am not going to go into great detail on the G protein-coupled receptors.
There will be a separate lecture for that.
However, just as an overview, let me walk through what's happening.
This picture on the right represents six basic steps of a G protein-coupled receptor.
Let's zoom in on step one.
Okay, what we have here is the receptor within the membrane of the cell.
The brown oval near the top represents the ligand.
In this case, we're talking about Acetylcholine or Muscarine.
The ligand binds to the receptor and induces a conformational change.
This conformational change activates the alpha sub unit, which then exchanges its GDP for GTP.
Пікірлер: 214
Every time he says "ISN'T THAT COOL" I find myself grinning while nodding enthusiastically like what the hell! This is SO cool! I can't believe how much I used to hate that shit when they actually make a lot of sense! Just THANK YOU! You're my hero ❤
@sharonife9994
5 жыл бұрын
I know right. ...so damn cool
Your videos on receptors has been HUGE for me! Thanks so much.
This is the first video on these receptors that actually helped me. Thank you so much!
you are like... THE HERO !
@nomsyemmanuel2717
7 жыл бұрын
F
@danishlone3441
4 жыл бұрын
Indeed
This is the best summary video I have found so far for cholinergic receptors. THANK YOU!
Thank you so much for this! Thank you!! You've really helped me, I have been struggling with these concepts for s long and now that I finally get it I feel a lot more confident about my finals, thank you so much
Yeah, this lecture was the shit. I am studying pharma right now for my NCLEX exam I am taking soon, and I am too lazy to just memorize without understanding therapeutic/side effects of medications without at least trying to understand WHY they exist. Videos like this really hammer home concepts that allow me to understand and not just memorize side effects, etc. I feel like much of the nursing text spits out terms that we just don't have enough time to delve into further. I have a problem with that. (I have OCD) I loved the diagrams for the PNS and SNS systems and the nerve innervations. Explanations were super clear. Even as a nursing student, I did pick up on the 'Chromotropic' error, haha. I am just not content to know the basics, I need more because it scares the shit out of me in a good way that my knowledge of this stuff is gonna help me to better communicate to providers to increase patient safety. Thanks.
@MedImmersion
8 жыл бұрын
+Scott Genereau - Good luck dude!
@masihmasihmasih
7 жыл бұрын
hahaha lolz i thought you wrote "Yeah, this lecture was shit" i was like da hell this is good hahah
@valentinanikolic1272
7 жыл бұрын
Scott Genereau
@dollarking9641
6 жыл бұрын
Ur comment is too long
@nrcg2317
5 жыл бұрын
Goodman & Gilman's the pharmacological basis of therapeutics has an excellent description of the autonomic nervous system and how drugs function on it. You won't have to memorize. This cannot be memorized. You have to understand the logic.
This is really helpful. I was quite confused when I first learned this in class, now I'm studying for step 1 and the language had be SUPER confused. For instance, people using the words anticholinergic and antimuscarinic interchangeably with parasympathetic inhibition - when in fact they aren't the same. This video really helped me to understand what the differences are between those - it all has to do with the different sub-types of receptors.
@MedImmersion
8 жыл бұрын
I'm glad I could help Lomo!
This is the most informative and interesting pharmacology lecture I have ever heard! Thanks alot!
Sir, you're a life saver and a great instructor
You do a great job putting things together and making it make more sense! Thank you for your time building these videos!
@MedImmersion
9 жыл бұрын
You are very welcome!
Thank you so much! I feel that seeing your videos is a good invest of time.
I almost cried... so... perfect. Thank you very much for making this lecture.
@MedImmersion
6 жыл бұрын
Awww - I almost cried at your nice comment... I'm a resident right now guys so I'm sorry that I don't have time to work on medimmersion. Hang in there, school is over before you know it!!
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@MedImmersion
7 жыл бұрын
+Luke Twaits Your welcome!
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Perfect lecture !! Thanks alot :)
Great videos ! I have a much clearer understanding of the receptor functions now thank you. Could you possibly make videos regarding Gi and Gq proteins please?
so nice …. so cool ...good luck
Thank you this is soo helpful 👌🏻❤️
thanks doc,you have helped me on this,thanks allot.
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Thank you so much for this!
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Awesome video. Thank you very much...!!!
these lectures are just awesome but i need others too e.g., indirect adrenergic agonists or adrenergic antagonists etc
You are a fantastic teacher!!!!!!
@MedImmersion
9 жыл бұрын
Mira le Paulsen Thanks Mira! Good luck in school.
Thank you for the clarity! Very helpful, indeed:)
@MedImmersion
9 жыл бұрын
Good, I'm happy to help!
Thanks Doctor ! :) You are the best :)
Excellent Presentation
thank you , thank you !!
the fantastic vedeao i got today, easy perfect ,i hope more and more or all pharmacology
Great work ...thanks for the pain taken to explain it so well
@MedImmersion
9 жыл бұрын
Thanks doc!
loved it !!!
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@MedImmersion
9 жыл бұрын
oanh phạm You're welcome Oanh!!
Really good video man!
Dude you’re awesome!
Great work mate, this is way more helpful than my lazy Pharmacology lecturers.
@MedImmersion
9 жыл бұрын
Good! I'm glad you like it. Stay tuned for more mate! : )
This is really helpfull thank you so much sir
thank u so much for all useful videos .do you have any videos for cholinergic antagonist or agonist?please
Superb❤
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Thanks!!
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@MedImmersion
8 жыл бұрын
+jaqueline Manuel - No, you're a great student!
@MedImmersion
8 жыл бұрын
+jaqueline Manuel - No, you're a great student!
just awesome......!!!!!!!how can u be so cool while explaining lecture....
@MedImmersion
8 жыл бұрын
It's easy. I wear sun glasses, a bath robe, and Nike sandals over my socks while listening to vanilla ice, and bobbing a pipe from my mouth. After that, the "cool" just flows like a harpoon daily and nightly
@ravykiran8928
8 жыл бұрын
as expected.....lol
Sir I Salute you.Thank you.
@MedImmersion
9 жыл бұрын
Haha! Roger that dude! Thanks!
Thank you
good lecture
Awesome. ...thanks
@MedImmersion
9 жыл бұрын
I'm glad it helped.
Wonderful
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@MedImmersion
9 жыл бұрын
You're welcome!
Thank very much
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You Rock!!!!
Fantastic! Any chance there are printable notes to accompany this lecture?
Very good, thanks
@MedImmersion
9 жыл бұрын
I'm happy it helped!
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@MedImmersion
9 жыл бұрын
You are very welcome!
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This Veterinary student thanks you!!!
@MedImmersion
9 жыл бұрын
You're welcome Jacqueline! Good luck in school!
Thank you sir :)
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very much helpful