 Hey, have you heard about this thing called the nervous system of your body if you're wondering no It's not a system designed to make you feel nervous. That's not what it is But then what is it? Well, let's find out So the nervous system is kind of like the wiring system in your body And one of its main jobs is to allow your brain to control all of your muscles For example, let's say you want to wave your hand saying goodbye to someone Let's see how that happens. Let me zoom in a little bit so here you are and Let me bring in your bicep muscles because we will see they will be used All right, so let's say you decide to say bye-bye to someone the moment you decide that Electrical signal gets generated in your brain and that electricity starts passing down your wires the nerves the wires They will go into your biceps and Then when that electricity hits the biceps, you know what happens the bicep contracts And as a result at the same time the bicep starts pulling your forearm and that's how your forearm goes up and Then when that electricity is gone, your bicep will come back and it relax and your arm will come back down And this is how you do goodbye without thinking about it Maybe do some uninvited guest in your house and so one of your main jobs of the nervous system is to Allow your brain to control all the muscles of your body And it does that by using electricity But that's not all your nervous system also allows your brain to understand what's happening in its surrounding For example, let's say you are in a classroom this time and one of your friend taps on your shoulder from behind What happens now? Well now the nerves which are present near the skin of your shoulder They immediately generate electricity the moment you touch it They generate electricity and then the electricity goes from there all the way up to your brain and Then your brain processes it it understands where the electricity came from from which nerve it came and it realizes Ah, my left shoulder got touched And now maybe if your teacher is facing you then you will not do anything But the moment the teacher turn turns back Immediately another signal gets into your brain and that signal now goes and contracts your neck muscles and immediately You'll turn back to talk to your friend Isn't that cool? Every single thing that you're sensing right now and every single motion that you can do with your body is due to your nervous system And this is not just for touch all other senses also work this way For example, when you look at something the light falls on your eyes and that gets converted to electricity It gets sent to your brain if you are smelling something again that gets converted to electricity Electricity gets sent to your brain. So you see another thing about the nervous system one of the important jobs of your nervous system It allows all your senses to communicate with your brain using electricity And so this works for all five of your senses Unless of course you are spider-man in which case you will have a sixth sense to but I'm not sure how that would work Okay, so this nervous system is pretty cool, right? But you may be wondering but what exactly is it made of is it really wires do I have copper wires in my body? No, of course. These are not wires. Then what are they? Well, just like anything in our body. They are made of cells Okay, so if you were to zoom into to one of these nerves and you find that actually cells Arranged end-to-end and if you're wondering hey, that's not what a cell looks like I hear you because these are highly modified cells. I mean, they also have a nucleus and everything But they don't look like regular cells. I totally agree with you These are called neurons very specialized cells and they are the ones that conduct electricity But of course, I won't talk too much about these neurons mainly because we have another video Completely dedicated to talk about their awesomeness. Okay, so let's not worry about the neurons and the cells as of now Let's think of them as wires as of now, okay? Okay, then another question we might be having is how many parts does this nervous system have? It looks super complicated super branched out and everything. So how many parts does it have? Well, it turns out that broadly we can divide this nervous system into two parts So let me zoom out a little bit so that we can see better All right. So the nervous system can be broadly classified into two parts Let me just write that down over here One is called the central nervous system. I'm just gonna write central over here central nervous system The short form for that is CNS Central nervous system and the second one is called the peripheral nervous system. So Peripheral Nervous system and its short form would be P N S P N S Okay, so what are they well the central nervous system as the name suggests is the central part of the nervous system Which involves the brain? Which is the command center and your spinal cord? That's right Even the spinal cord is the part of our nervous system. So these two things are the central nervous system again Let me just write that down So your central nervous system contains two parts two parts It contains the brain, which let me use purple for that and it also has spinal cord spinal cord Fine, then what's this peripheral nervous system? Well peripheral kind of means Adjacent to kind of means in the side. So peripheral nervous system is everything else besides the central nervous system Okay, so you can see all these branches These branches that you can see they are the peripheral nervous system Okay, and again based on from where they're branching we can classify them into two kinds So again, let me write that down. So even peripheral nervous system can be classified into two kinds If you have branching happening from the brain Okay, you can kind of see over here if they are branching from the brain. We call that as We call that cranial nerves. These are all nerves, right? So these branches coming from the brain are called cranial nerves and Then these branches coming from the spinal cord. They are called They are called spinal nerves Again the name pretty much helps us understand. What is what? Cranial comes from the word cranium, which is the part of the skull where the brain sits So let me show you the brain again Yeah, where the brain sits and therefore cranial nerves refers to the nerves that comes from the brain Spinal nerves refers to the nerve that comes from the spinal cord Let me just put a bubble around them. So these are broadly to two parts of our nervous system So here's a question. What do you think are the functions of these two things? We've already taken some examples and we've seen how the nervous system kind of works So can you pause the video and guess what the central nervous system does and what the peripheral nervous system does? Okay, so your central nervous system, what do you think it does? Well, since it has the brain in it if you guess that its main job is to process information You're absolutely right. Its main job is to process information collect all that information think about what to do decide Come up with a decision all of that stuff. That is your central nervous system Then what do you think your peripheral nervous system does? Well, we saw in our examples the peripheral nervous system Their job is to send the information from the brain to the muscles or maybe to send the information from your senses to your brain or sometimes send the information from your internal organs Let's say something gets injured then that has to information also has to be sent to the brain, right? So all the communication between the central nervous system and the other parts of your body the other organs in muscles That happens. Why are the peripheral nervous system? Okay, so peripheral nervous system you can I would just say crudely It allows the different parts of your body the different parts of your body to talk to the CNS Okay, so through the peripheral nervous system all the parts your muscles and your organs Communicate with your central nervous system So that's pretty much it So just to summarize our nervous system can be thought of a wiring system that allows our brain to Communicate with the rest of our body And it uses electricity to do that and we saw that there are two parts to it the central nervous system Which composes of brain and the spinal cord its main job is to process information and the peripheral nervous system All the other parts of the nervous system Except central nervous system is called the peripheral nervous system It's divided into cranial nerves the ones that come out branch out from the brain spinal nerves that branch out from the spinal cord and Their job is to communicate between the different parts of the body and the central nervous system