Neurotransmitter Receptors (Nursing)

00:01 Okay, now we've talked about the different nervous systems, that's the first step in peripheral nervous system understanding.

00:08 Now a neurotransmitter receptor is the next piece that you wanna know.

00:12 See, a neurotransmitter receptor is a structure on a cell's surface that binds to specific neurotransmitters.

00:20 That's why we call it a neurotransmitter receptor.

00:23 So it's a receptor, it's on a cell surface and it binds to specific neurotransmitters.

00:29 That's really a key.

00:30 It matters that only specific neurotransmitters will fit only specific receptors.

00:36 Okay, so let's give you some examples, cholinergic receptors bind to acetylcholine.

00:42 So look at the graphic we have for you there.

00:44 The little green dot is acetylcholine, that's what it represents.

00:48 The blue receptor you'll see is shaped just like the green ball, so they'll come together as a cholinergic receptor and acetylcholine.

00:57 Now the easiest way to remember this is look at we have choline in bold.

01:01 So underline that and then look in cholinergic receptors, thank you, that's at least an easy way to remember that what makes a cholinergic receptor a cholinergic receptor, is that it's mediated or it turns on by acetylcholine.

01:18 Now, another type of receptor are adrenergic receptors.

01:22 Now you'll see that these receptors is kinda pie-shaped but up there, we have three examples of receptors that will also fit into adrenergic receptors.

01:31 So, they combine to norepinephrine, dopamine or epinephrine and you'll see we have those letters up there for you.

01:38 Now, I know this might seem obvious but take a minute and see, would dopamine set off a cholinergic receptor? Nope, because it's not specific to that just like acetylcholine can't set off an adrenergic receptor, it's not set up for that.

01:55 So a receptor is uniquely fitted to certain neurotransmitters.

02:01 Acetylcholine goes to cholinergic.

02:03 Dopamine, norepinephrine and epinephrine go to adrenergic receptor.

02:09 Okay, let me give you another example.

02:11 Now, I don't know if you've ever gotten a mailer like this but I get this in the mail all the time from car dealerships.

02:17 It's a post card with a key taped to it.

02:20 Now they're trying to draw me into the car dealership to get me to come down there so that they can try and sell me a car.

02:26 So you get a post card like this, let me show you how it ties into receptors.

02:30 This is like the key players in the analogy, we couldn't avoid using that type of pun.

02:38 So, stay with me.

02:40 The ignition of a car and you have the ignition with the key in it.

02:44 Now the ignition represent the receptor, it might be cholinergic, that's mediated by acetylcholine.

02:50 It might be adrenergic, it could be nicotinic or muscarinic.

02:54 Now we haven't talked about nicotinic or muscarinic yet, we will.

02:57 But let's just, for the sake of discussion right now, the ignition is like the receptor.

03:03 It has a unique fit to it, only certain things will connect to it.

03:08 The key represents the transmitter like acetylcholine, epinephrine, norepinephrine or dopamine.

03:15 So just for fun, quiz yourself.

03:18 What type of receptor does acetylecholine mediate? Cool, I hope you said cholinergic receptors.

03:27 What about epinephrine? Awesome, those are adrenergic receptors are mediated by epinephrine.

03:33 Good job! So you're in track in with us.

03:36 If you're not quite there, just stop for a minute, go back and review those concepts.

03:41 The ignition represents the receptor and only certain substances fit into it.

03:47 The key represents the transmitter like acetylcholine for cholinergic, epinephrine for adrenergic.

03:53 Okay, now we have winner keys and we call those agonists and we have loser keys, we call those antagonist.

04:04 Now let me explain to you why we use those.

04:07 Okay, if a winner key is inserted in the ignition, I'm gonna put it in and turn it like a car will start, I'm a winner.

04:16 That's what an agonist does.

04:18 An antagonist will fit in the ignition but it won't let me start the car, that's why it's a loser.

04:26 So an agonist is a neurotransmitter or a drug that can bind to the receptor and activate the receptor.

04:34 Remember, the winner key fit right into the receptor of the ignition, I could turn it, Voila! the car starts, I'm a winner, the engine does what's it's supposed to do, it starts running.

04:46 An antagonist binds the receptor but it doesn't activate the receptor.

04:51 Remember the loser key? if I put it in the ignition, it won't start the car, right? But also if I just left it there, it would prevent the winner key from hitting that ignition, that's what an antagonist does.

05:05 It binds to the receptor, so technically it fits, but it doesn't activate the receptor and it prevents any other agonist from binding to the receptor.

05:15 Now this is really useful in peripheral nervous system, okay? So we have have agonist and we have antagonist and we have drugs that can do both purposes with our receptors.

05:27 We have drugs that will bind to a receptor and make it go and we have drugs that will bind to a receptor and block the action of that receptor.