The smart way to improve grades

Comprehensive & curriculum aligned

Affordable pricing from £10/month

Analyse Nerve Structure

In this worksheet, students will analyse the structure and roles of motor, sensory and relay neurones, as well as the function of synapses.

'Analyse Nerve Structure' worksheet

Key stage:  KS 4

GCSE Subjects:   Biology: Single Subject, Biology: Combined Science

GCSE Boards:   Pearson Edexcel

Curriculum topic:   Cells and Control

Curriculum subtopic:   Cells and Control

Difficulty level:  

Worksheet Overview

QUESTION 1 of 10

The nervous system is so important- it makes us notice danger, makes us react and protects us by using our senses!

 

Let’s begin with the most fundamental part of the nervous system: nerve cells!

 

 

Individual nerve cells are called neurones, and their main function is to transport electrical signals around the body to control our internal and external processes.

 

BUT a nerve is not the same as a nerve cell, as a nerve is a BUNDLE of nerve cells packed together.

 

Now, there are 3 types of neurones: Motor, Sensory and Relay Neurones, and while they are unique, they also share some common functional adaptions too:

 

Structural Adaptions of Motor, Sensory and Relay Neurones for their Functions

Motor Neurones Sensory Neurones Relay Neurones/ Interneurons

FUNCTION:

Motor neurones carry signals from the CNS to the target organs and muscles to perform an action

 

FUNCTION: 

They detect changes in our environment, or stimuli, from loud noises to temperature changes.

 

They carry this sensory information from stimuli in the peripheries to the brain and spinal cord of the CNS.

.FUNCTION:

A relay neurone can be in the spinal cord and the brain (anywhere in the CNS) and they help pass information between the sensory neurones and the motor neurones.

STRUCTURE:

Neurones have a cell body or soma with branches called dendrites which communicate with other cells.

 

The cell body leads to the axon, a long fibre that guides the signal to its destination. This can be very long e.g. one axon can stretch from your hip to your toe!

 

To speed up the electrical signals, the axon is wrapped in myelin sheaths, and it’s the myelin that insulates the axon. This area doesn’t conduct electricity, meaning the signal jumps down the fibre through uninsulated gaps called the nodes of Ranvier, ending in the axon terminals of the neurone.

STRUCTURE:

Sensory neurones have specialised cells called receptors in the periphery of our bodies that detect stimuli, and so sensory cells have no dendrites.

 

Their axons are short but also insulated with myelin, as you can imagine, if our finger is on fire, we need to register this and react fast, so the faster the signal can travel the more control our bodies have!

STRUCTURE:

The relay neurone can also be called an interneuron.

 

(think that it runs interference between the sensory and motor neurones!)

 

Their structure is very similar to motor neurones, although their dendrites are short and their axons can be long AND short!

 

Important Note: Dendrites are not axon terminals!!

 

Dendrites are on the cell body and axon terminals are on the other end of the neurone after the axon.

 

 

Synapses

When the neurones want to do their functions, they need synapses to communicate and pass along the electrical signals. 

 

Synapses are the connection between the dendrites and axon terminals of two cells.

 

Electrical signals can't pass through the air so in the axon terminal, it's converted into specific chemicals called neurotransmitters.

 

These pass across a gap called the synaptic cleft to the receiving receptors on the dendrites of the other cell, where they trigger another electrical signal to be passed down the axon. 

 

 

 

So let's put everything together- what happens when you touch something sharp?

 

1. Sensory receptors detect pain in the skin cells of your finger

 

2. An electrical signal is generated at the cell body and travels down the sensory axon to the axon terminals

 

3. Here the sensory axon terminals synapse with relay neuron and communicate with specific neurotransmitters

 

4. The relay neurone carries the signal to its terminals which then synapse with the motor neurone

 

5. A motor neurone then takes the electrical signal to the muscles of the finger, and makes them contract to make you move away from the stimulus.

A neurone is a...

Single nerve cell

Bundle of nerve cells

Type of receptor

Type of chemical

The 3 different types of neurones are motor, sensory and what?

What are the functions of these nerve cells?

Column A

Column B

Motor Neurone
Signal is carried from the PNS to the CNS after be...
Sensory Neurone
Passes on information between neurones
Relay Neurone/ Interneuron
Signal is carried from the CNS to the PNS to perfo...

What is another name for the cell body of a neurone?

Identify which adaption belongs to which nerve cell type:

True or False:

 

The terms 'dendrites' and 'axon terminals' are interchangeable 

What special adaptions do relay neurones have in their structure?

 

[Select ALL the correct answers]

Long AND short axons

Receptors

Short dendrites

Many somas

Neurones are well designed for their function:

Long AND short axons

Receptors

Short dendrites

Many somas

What happens at synapses?

Long AND short axons

Receptors

Short dendrites

Many somas

Look at this scenario:

 

'Susie is playing with a candle and her finger accidentally touches the hot wax'

 

What happens next?

Column A

Column B

1.
The sensory neuron passes the signal down its axon...
2.
Sensory receptors in Susie's finger detect heat an...
3.
The muscles in Susie's finger receive this signal ...
4.
Motor neurone dendrites pick up the signal on the ...
5.
The interneuron picks up the signal, sends it down...
  • Question 1

A neurone is a...

CORRECT ANSWER
Single nerve cell
EDDIE SAYS
This is a key term that many students get confused with. A NEURONE is a single nerve cell, but a NERVE is a bundle of neurones/ nerve cells!
  • Question 2

The 3 different types of neurones are motor, sensory and what?

CORRECT ANSWER
RELAY NEURONE
INTERNEURON
EDDIE SAYS
The 3 key players are the motor neurones, the sensory neurones and relay neurones which are also called interneurons. Click next to practise more questions about their structure and function!
  • Question 3

What are the functions of these nerve cells?

CORRECT ANSWER

Column A

Column B

Motor Neurone
Signal is carried from the CNS to...
Sensory Neurone
Signal is carried from the PNS to...
Relay Neurone/ Interneuron
Passes on information between neu...
EDDIE SAYS
How confident did you feel going into this question? Sensory neurones detect the stimulus or change in the environment, and their signal is carried from the peripheral nervous system to the CNS. It's then that the motor neurones carry instructions in the form of electrical signals from the brain or spinal cord to the target organ or muscle where the stimulus occurred, creating a response. And relay neurones work between them to promote communication.
  • Question 4

What is another name for the cell body of a neurone?

CORRECT ANSWER
SOMA
EDDIE SAYS
This is just one of those terms to learn, as the word soma and cell body mean the same thing and different teachers and textboxes will use different terms for the same thing!
  • Question 5

Identify which adaption belongs to which nerve cell type:

CORRECT ANSWER
EDDIE SAYS
While motor, sensory and relay cells are all neurones and share some common characteristics, they are heavily adapted for their unique functions and so have some key structural differences. Motor neurones look like the typical neurone image, with long axons, plenty of dendrites on the cell body and ending in axon terminals. Sensory neurones, however, have short axons, receptors instead of dendrites and actually have their cell body halfway down the cell as a branch of the axon.
  • Question 6

True or False:

 

The terms 'dendrites' and 'axon terminals' are interchangeable 

CORRECT ANSWER
EDDIE SAYS
This is DEFINITELY FALSE and a key point many students learn wrong early on and have trouble with later in their learning. Dendrites are on the soma of cells while axon terminals are on the other end after the axon- so one is at the head and the other is at the tail! It's easier to realise them as two separate things when you realise that a synapse occurs between an axon terminal and a dendrite, so they must be different as a synapse is between the end of one cell and the start of another!
  • Question 7

What special adaptions do relay neurones have in their structure?

 

[Select ALL the correct answers]

CORRECT ANSWER
Long AND short axons
Short dendrites
EDDIE SAYS
Compared to the motor and sensory neurones, interneurons can have long and short axons, and also have short dendrites, although receptors are for sensory neurones only and none of the neurones has more than one soma.
  • Question 8

Neurones are well designed for their function:

CORRECT ANSWER
EDDIE SAYS
Did you do as well as you hoped? Myelin sheaths are excellent insulators and stop electrical signals being carried throughout the whole axon, forcing it to jump down the fibre using the nodes of Ranvier which are just gaps where there is no myelin wrapped around the axon. This speeds up the electrical signal and helps neurones work effectively.
  • Question 9

What happens at synapses?

CORRECT ANSWER
EDDIE SAYS
We're really getting into the fine detail of neurology now, but this is good practice for the level of understanding you should aim for to stay on track for your desired grade. As electrical signals can't pass through air, when neurones synapse, the signal is converted into NEUROTRANSMITTERS which are chemicals specifically designed to be recognised and only fit the uniquely shaped receptors on the ends of the receiving dendrites of the other cell. And the gap between the two neurones that the neurotransmitters pass across is called the synaptic cleft.
  • Question 10

Look at this scenario:

 

'Susie is playing with a candle and her finger accidentally touches the hot wax'

 

What happens next?

CORRECT ANSWER

Column A

Column B

1.
Sensory receptors in Susie's fing...
2.
The sensory neuron passes the sig...
3.
The interneuron picks up the sign...
4.
Motor neurone dendrites pick up t...
5.
The muscles in Susie's finger rec...
EDDIE SAYS
How did you get on with this mean final question? How all the structures we've learnt about come together to perform their function is a vital takeaway concept in this topic and so practising questions like this will help you greatly in terms of your understanding. So let's run through how this all works: 1. Sensory receptors detect a stimulus 2. An electrical signal is generated at the cell body and travels down the sensory axon to the axon terminals 3. Here the sensory axon terminals synapse with relay neuron and communicate with specific neurotransmitters 4. The relay neurone carries the signal to its terminals which then synapse with the motor neurone 5. A motor neurone then takes the electrical signal to the target organs or muscles so you can perform an action in response to the stimulus So all the neurones come together to detect, act and help our bodies with safety and control. Well done on this very wordy topic and don't forget to jot down any explanations that you felt really helped you come to grips with some of the harder things when it comes to nerve structure!
---- OR ----

Sign up for a £1 trial 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

Start your £1 trial today.
Subscribe from £10/month.