Select Page

063 The Divisions of the Nervous System

063 The Divisions of the Nervous System

Join Leslie as he gives you a review of the brain and it’s different major divisions.


Transcript of Today’s Episode

Hello and welcome to another episode of Interactive-Biology TV, where we’re making Biology fun! My name is Leslie Samuel and in this episode, Episode 063, we’re going to take a step back, and we’re going to talk about the divisions of the Nervous System. Let’s get right into it.

If you go all the way back to Episode 001, we spoke about the Nervous System. We said that the nervous system is basically the ‘control center’ of the body.

What we’re going to do is we’re going to take this, and we’re going to look at the divisions within the nervous system. First, we have the Central Nervous System, and we have the Peripheral Nervous System. These are the two systems that we can divide the nervous system into.

The Central Nervous System, that is the processing center of the nervous system. A lot of processing happens here. The Peripheral Nervous System is what connects the Central Nervous System to the limbs and the organs. So, we have the processing in the central, and then, we have the Peripheral Nervous System. These work together very well.

Now, let’s take the Central Nervous System and divide that. That can be divided into the brain and the spinal cord. The brain, that’s center of the nervous system. This is where most of the processing are happening. This is the part that’s found within the skull. This is where things like thought, and emotion, coordinating the body’s activities, all of that stuff happens in the brain.

Then, of course, we have the spinal cord. The spinal cord sends signal to and from the brain, to and from the rest of the body. So, it’s connecting the brain to the rest of the body, basically. Sensory signals come in to the spinal cord, and motor signals go out from the spinal cord. We’re going to talk about those as we deal with the peripheral nervous system. Let’s head on over there right now.

The peripheral nervous, once again, consists of two parts: that’s the Somatic Nervous System and the Autonomic Nervous System.

Let’s talk about the ‘somatic’ first. The Somatic Nervous System is where we’re going to get control of voluntary activities. This is where skeletal muscles are involved. If, for example, I want to walk. I need to contract the muscles in my legs. That is voluntary activity that is controlled by the somatic nervous system. If I want to smile and you can control the muscles in my face. By the way, it takes less muscles to smile than to frown. But, I’m sure you know that. This is all in the Somatic Nervous System.

And, then of course, we have the Autonomic Nervous System which is not voluntary. This is the involuntary things that happen in the body. So, it controls visual functions like heart rate, respiration rate, digestion, those things you don’t need to think about. They just happen. They are “involuntary,” and that is under the control of the Autonomic Nervous System.

We can take the Autonomic Nervous System, and of course, we’re going to divide that into two parts. We have the Sympathetic Nervous System and the Parasympathetic Nervous System.

The Sympathetic Nervous System, that is involved in the ‘flight or fight response.’ It’s what happens to your body when your body is under stress. Things like increasing your heart rate and respiration rate… Anything that you’re increasing. This is usually under the control of the sympathetic nervous system. So, if you go for a nice long jog, and you’re heart rate starts increasing and your respiration rate increases, that is under the control of your sympathetic nervous system.

Then, of course, we have the parasympathetic, which is opposite to the sympathetic. This is involved during rest and digest activities. It’s the opposite of under stress. It’s when there is rest. You’re slowing things down. You’re relaxing. That is more parasympathetic. These are both under the autonomic nervous system.

So, there we have it. Those are the divisions of the nervous system. I hope that was clear to you. That’s pretty much all I want to cover in this video. As usual, I want to invite you to visit the website. You know it. It’s at There, you can get other Biology videos, and resources to help make Biology fun. This is Leslie Samuel, and I’ll see you in the next one.

About The Author

Leslie Samuel

Leslie Samuel is the creator of Interactive Biology. His mission is to use this site to Make Biology fun for people all over the world.

Struggling in Biology?

Are You Premed?

Confused about the MCAT? Not sure how to prepare? This guide will show you how