The smart way to improve grades

Comprehensive & curriculum aligned

Try an activity or get started for free

Describe the Nervous System

Worksheet Overview

QUESTION 1 of 10

Image of toilet

 

Did you know that we need our nervous system to pee?! 

The nervous system is a system that allows us to control our body and gives us feedback about the world. Without it, we would struggle to do basic things like going to the toilet!

 

Image of the nervous system

 

 

The nervous system is made up of two parts:

The central nervous system (CNS), which includes the brain and spinal cord.

The peripheral nervous system (PNS), which are the nerves that carry information to and from the CNS. 

 

So how does the nervous system work exactly? 

We react to changes in the environment, so if it's really bright and sunny outside, we might squint and turn away from the sun. We would call the sunlight in this example a stimulus. It's a change in your environment which you need to react to. Other examples might be sound or smell. Our sense organs detect the stimuli -  these organs are our eyes, ears, nose, tongue and skin. Our sense organs all contain different receptors. 

Receptors are groups of cells which are sensitive to stimuli. They change stimulus energy (e.g. light energy) into electrical impulses. These impulses are passed along neurones (you'll find out more about neurones below) to the central nervous system (often referred to as the coordinator). The neurones then pass the impulses to effectors, which are often muscles and glands. A reaction is then made, such as moving your head away from direct sunlight in the example given above. This pathway can be demonstrated in a flow diagram like the one below:

 

Flowchart of how the nervous system works

 

 

A nerve cell or neurone has many features. One of its features is a tail-like structure called the axon, which can be really long. This allows nerve impulses to travel around the body at lightning-fast speed. The axon also allows nerve impulses to be passed along to other effector cells like muscles, or to other neurones. Where the neurones meet, there is a gap called a synapse. It's here where a  specific chemical passes on the impulse.

Neurones are covered in a blanket of fatty cells called the myelin sheath. This helps to protect the nerve cell from damage and also to speed up the transmission of nerve impulses.

Another feature of the nerve cell are the dendrons. Dendrons are branches (that further divide into dendrites), which receive nerve impulses from other nerve cells.

 

Image of a nerve

 

There are three types of neurones: sensory, motor and relay. Sensory neurones pass on impulses from our senses to the CNS, whereas motor neurones pass on impulses from the coordinator, normally the CNS, to muscles or glands (the effectors). Relay neurones connect the sensory neurone to the motor neurone -  they're found in the spinal cord and so don't need to travel to the brain.  

 

Image of different neurones  

 

What are reflexes?

Reflexes are designed to allow you to respond to a potentially dangerous situation very quickly. As there is no time to think, the brain doesn't need to be involved. These actions are still coordinated by the CNS, but by the spinal cord rather than the brain.

 

Image of relay arc

 

Reflexes need to happen really fast -  this way you're protected from harm. For example, if you touch a hot pan, your reflexes cause you to pull your hand away really quickly before you burn yourself. 

The pathway that is followed in a reflex action is called a reflex arc:

 

stimulus → receptor→ sensory neurone →relay neurone → motor neurone → effector→ response

 

In the example of touching a hot pan:

A hot pan is the stimulus → detected by receptor cells in the fingertips → nervous impulse from fingertips to sensory neurone → impulse sent to relay neurone in spinal cord → impulse is passed onto motor neurone  → passed onto the effector, which is the muscles in the fingers → response is to move the hand away from the hot pan.

Reflexes are known to be autonomic - they don't require any conscious thought - and our body relies on these for things like heart rate, blood pressure and metabolism.


In the following activity, you will be describing the role and different parts of the nervous system.

What are the functions of the different parts of the nervous system listed below?

Column A

Column B

Sensory neurone
The gap that allows impulses to pass to another ne...
Synapse
Passes on impulses from sense organs to the coordi...
Relay neurone
Neurone that connects a sensory and motor neurone
Motor neurone
Passes impulses to an effector

The myelin sheath wraps around the axons of nerve cells. Multiple sclerosis (MS) is a disease that causes your immune system to attack the myelin sheath.

 

How might this affect nerve transmission? 

 

Image of a nerve

Nerve transmission is faster than normal

Nerve transmission is slow or may not happen at all in some cases

Nerve transmission is not affected

How do the different parts of a motor neurone work together to ensure the nerve cell is highly specialised? 

Nerve cells receive impulses from other cells via the axons, which are then transmitted away from the cell body down the myelin sheath. This happens very slowly due to the insulation provided by the myelin sheath

Nerve cells receive impulses from the coordinator via the dendrites, which are then transmitted down the axon. This happens very fast due to the insulation provided by the myelin sheath

Nerve cells receive impulses from other cells via the dendrites, which are then transmitted away from the cell body down the tail. This happens very fast due to the insulation provided by the myelin sheath

Which of the following organs is part of the central nervous system? 

Heart

Lungs

Brain

Select the organs in which you would find receptors that are sensitive to light, sound and touch.

 

Image of sense organ

What is the name of the junction (A) between the two neurones in the picture below?

 

Image of reflex arc and synapse

 

 

A and B on the picture below are parts of the nervous system.

 

Label A and B.

 

Image of the CNS 

A: Spinal cord

A: The brain

B: Muscles

B: Nerves

Reflexes are autonomic -  they keep us safe, and control so many vital processes, such as our heart rate.

The image below shows a reflex arc. 

 

Label A, B and C. 

 

Image of relay arc

Column A

Column B

A
Effector/muscle
B
Receptor
C
Sensory neurone

Why are reflexes so important?

They keep us safe from possible harm by causing a quick reaction

They keep us safe from possible harm by reacting slowly

They allow you to choose your response

Label the parts 1, 2 and 3 of the nerve pathway below:

 

Image of nerve pathway

 123
Response
Stimulus
Central nervous system
  • Question 1

What are the functions of the different parts of the nervous system listed below?

CORRECT ANSWER

Column A

Column B

Sensory neurone
Passes on impulses from sense org...
Synapse
The gap that allows impulses to p...
Relay neurone
Neurone that connects a sensory a...
Motor neurone
Passes impulses to an effector
EDDIE SAYS
These are really key terms you need to remember, so have a few tries in order to consolidate your learning. There are a few tips that might help you to remember which is which. The sensory neurone is to do with your senses and is connected to your sense organs. The motor neurone is to do with movement - the impulses may trigger a movement. The relay neurone passes an impulse on - just like passing the baton on during a relay race!
  • Question 2

The myelin sheath wraps around the axons of nerve cells. Multiple sclerosis (MS) is a disease that causes your immune system to attack the myelin sheath.

 

How might this affect nerve transmission? 

 

Image of a nerve

CORRECT ANSWER
Nerve transmission is slow or may not happen at all in some cases
EDDIE SAYS
The job of a nerve cell is to transmit or carry information via nerve impulses to different parts of the body. When the myelin sheath is damaged, the nerves can also be damaged and scarred. This makes it harder for the nerve cells to transmit impulses, which can lead to weakened muscles, coordination issues and even paralysis.
  • Question 3

How do the different parts of a motor neurone work together to ensure the nerve cell is highly specialised? 

CORRECT ANSWER
Nerve cells receive impulses from the coordinator via the dendrites, which are then transmitted down the axon. This happens very fast due to the insulation provided by the myelin sheath
EDDIE SAYS
Don't despair if you weren't too sure with this one. There was a lot to think about with all these options. These different parts of the nerve cell make it really specialised and suited to its job. Dendrites are the tiny branches that receive impulses and pass them along to the axon. Remember, the axon looks like a tail (it's not a tail though, so don't write that in an exam!) and the myelin sheath is a fatty covering surrounding the axon. The impulse travels down the axon to the synapse, where it is passed along to an effector cell - such as a muscle cell, for example.
  • Question 4

Which of the following organs is part of the central nervous system? 

CORRECT ANSWER
Brain
EDDIE SAYS
How did you get on with this first question? The central nervous system, or CNS, is made up of the brain and also the spinal cord. The heart is a crucial part of the circulatory system and the lungs are the key organ in the respiratory system.
  • Question 5

Select the organs in which you would find receptors that are sensitive to light, sound and touch.

 

Image of sense organ

CORRECT ANSWER
EDDIE SAYS
Your sense organs are where the receptors are found. These receptors will pass on the nervous impulse to a sensory neurone.
  • Question 6

What is the name of the junction (A) between the two neurones in the picture below?

 

Image of reflex arc and synapse

 

 

CORRECT ANSWER
synapse
a synapse
the synapse
EDDIE SAYS
The synapse helps nerve impulses to be passed on quickly to other neurones. They are highly specific, so it means that nerve impulses travel to where they're meant to go.
  • Question 7

A and B on the picture below are parts of the nervous system.

 

Label A and B.

 

Image of the CNS 

CORRECT ANSWER
A: The brain
B: Nerves
EDDIE SAYS
Don't forget, there are two parts to the nervous system. The CNS is made up of the spinal cord and the brain - marked A in the image. The PNS - the peripheral nervous system - includes the nerves (marked B) that connect up to the CNS.
  • Question 8

Reflexes are autonomic -  they keep us safe, and control so many vital processes, such as our heart rate.

The image below shows a reflex arc. 

 

Label A, B and C. 

 

Image of relay arc

CORRECT ANSWER

Column A

Column B

A
Receptor
B
Sensory neurone
C
Effector/muscle
EDDIE SAYS
The trick is to remember that after the stimulus, a nerve pathway will always start with a receptor and end with the effector, which brings about a response. Does it help you if you remember that both end and effector start with the same letter?!
  • Question 9

Why are reflexes so important?

CORRECT ANSWER
They keep us safe from possible harm by causing a quick reaction
EDDIE SAYS
Reflexes are important for our survival, allowing us to react really quickly to possibly dangerous situations. Certain drugs can affect our reflexes and slow down our responses, which is why it's illegal to drink alcohol and drive.
  • Question 10

Label the parts 1, 2 and 3 of the nerve pathway below:

 

Image of nerve pathway

CORRECT ANSWER
 123
Response
Stimulus
Central nervous system
EDDIE SAYS
Take the time to remember the different parts of the nerve pathway. You could try a mnemonic maybe: Silly Riddles Create Excellent Results Stimulus → Receptors → CNS → Effector → Response You've completed this activity now, but if you found it tricky, it might be a good idea to read the Introduction once more and have another go at these questions - just to consolidate your knowledge.
---- OR ----

Get started for free so you can track and measure your child's progress on this activity.

What is EdPlace?

We're your National Curriculum aligned online education content provider helping each child succeed in English, maths and science from year 1 to GCSE. With an EdPlace account you’ll be able to track and measure progress, helping each child achieve their best. We build confidence and attainment by personalising each child’s learning at a level that suits them.

Get started
laptop

Try an activity or get started for free