The smart way to improve grades

Comprehensive & curriculum aligned

Affordable pricing from £10/month

The Nervous System

In this worksheet, students will study the structure of the Nervous System and how it works. They also look at reflex actions and the role they play in our survival.

Worksheet Overview

QUESTION 1 of 10

The Nervous System carries information around the body in the form of electrical impulses (messages) in cells specialised for this job, the nerve cells. The nerve cells are called neurones. The main organs in the nervous system are the brain and the spinal cord, which make up the Central Nervous System (CNS). The nerves to and form the spinal cord make up the Peripheral Nervous System. You can see the main organs and major nerves of the human body in the diagram. It is worth noting that every space in our body is covered by nerves even if only the major ones are shown in the diagram.

 

The central and peripheral nervous system.

 

The Nervous System controls voluntary and involuntary actions. The voluntary actions are the ones we think about doing first, whereas involuntary action is called reflex and it is not thought about; it is fast and automatic. 

 

The neurone

 

A nerve cell

 

This is a diagram of a neurone, specifically a motor neurone. Motor neurones carry signals from the CNS to effectors. Effectors are the parts of the body that perform the actions, for example muscles. As you can see, neurones have long bodies with an axon for structure, which is protected by a fatty sheath, in order to prevent chemical impulses crossing over. At either ends of the axon there are dendrites, which branch out to receive or pass signals from/to other neurones or receptors (organs that recognise stimuli) and effectors.

There are two other types of neurones; the sensory neurone that carries signals from receptors to the CNS and the relay neurone that carries signals from one part of the CNS to another.

 

Synapse

Signals have to pass from one neurone to another. There is a gap between neurones called the synapse. When an electrical impulse approaches the synapse it triggers the release of chemicals called neurotransmitters, such as acetylcholine. These substances diffuse across the synapse, allowing the impulse to be carried along.

 

Voluntary actions

When we want to perform an action, for example picking up our keys to leave our house, neurones carry the message to the brain and the brain sends signals to the appropriate part of the body to do this action - in our example to lift our arm and grab our keys with our hand and fingers.

 

Reflex actions

It is important that our nervous system can perform actions without us thinking about them first in order to protect us from danger. Reflex actions are fast and automatic, as mentioned earlier and the impulses are not carried all the way to the brain to save time. Instead, they travel only to the spinal cord and then to effectors. Here is a diagram of a reflex arc:

 

A reflex arc

 

A stimulus (sudden change in circumstances), such as a hot plate is received by a pain receptor in the skin. A sensory neurone carries the information to the spinal cord and it is passed to a motor neurone through a relay neurone. The motor neurone carries the information to an effector and so we have a response, which in this case would be our hand dropping the hot plate to avoid burning.

Humans are considered the most clever of all living organisms, because we have a big brain. Our head occupies a big part of our body to provide space for our big brain. Look at the picture of a Stegosaurus:

 

A Stegosaurus

 

Tick two sentences that are true of this dinosaur.

It had a very small head in comparison to its body.

It was a very clever dinosaur.

Having a small head implies a small brain which probably means it was not very clever.

It was a very weak dinosaur.

What is the job of the nervous system?

It carries oxygen and glucose to all parts of the body

It provides movement to the body

It carries electrical impulses around the body

Complete the sentence by filling in the boxes in the table below:

 

The CNS is made up of the ____A_____ and the ______B_______.

image of the CNS and PNS

 Missing Words
A
B

What does the peripheral nervous system do with electrical impulses? Two of the statements below are correct.

The nerves carry messages from the brain and the spinal cord

The messages are in the form of electrical impulses

The nerves carry blood around the body

The nerves carry oxygen around the body

Tick two sentences that describe functions of the nervous system.

Reflex actions to prevent us from harming ourselves

Protects us from cosmic rays

Voluntary actions, where we do something without thinking about it

Voluntary actions, where we think about something and then do it

Tick three of the actions that you think are reflex actions.

Knee jerk reaction

Picking up our purse before going out

Taking hand away from a sharp object

Eye pupils get smaller in bright light

Complete the sentence by writing the missing words in the boxes in the table below:

 

Sensory neurones carry impulses ___A___ from a sense organ, whereas motor neurones carry impulses to an ______B_____.

 Missing Words
A
B

What is a synapse? 

A connection between neurone and the spinal cord.

A gap between two neurones that allows the electrical impulse to cross through a nerve cell.

A gap between two neurones where the electrical impulse is transmitted with the aid of chemicals called neurotransmitters.

Tick the correct definition of a relay neurone.

A nerve cell that carries impulses away from a sense organ

A nerve cell that carries impulses from one part of the CNS to another

A nerve cell that carries impulses to an effector

The steps of the reflex arc are listed in the correct order below. However, not all of the statements are correct. Tick the two wrong statements.

A stimulus is picked by a receptor

The impulse is carried along a sensory neurone to the brain

A relay neurone passes the impulse from the brain to a motor neurone

The motor neurone carries the impulse to an effector

The effector performs its action

The effector's response protects us from danger

  • Question 1

Humans are considered the most clever of all living organisms, because we have a big brain. Our head occupies a big part of our body to provide space for our big brain. Look at the picture of a Stegosaurus:

 

A Stegosaurus

 

Tick two sentences that are true of this dinosaur.

CORRECT ANSWER
It had a very small head in comparison to its body.
Having a small head implies a small brain which probably means it was not very clever.
EDDIE SAYS
Stegosaurus weighed half a tonne and had a very small head compared to its huge body. Small head is a sign a small brain, which means...stegosaurus was not very clever!
  • Question 2

What is the job of the nervous system?

CORRECT ANSWER
It carries electrical impulses around the body
EDDIE SAYS
The role of the nervous system is to carry messages in the form of electrical signals around the body. They are quick acting signals that don't last very long.
  • Question 3

Complete the sentence by filling in the boxes in the table below:

 

The CNS is made up of the ____A_____ and the ______B_______.

image of the CNS and PNS

CORRECT ANSWER
 Missing Words
A
B
EDDIE SAYS
The CNS (central nervous system) is made up of the brain and the spinal cord. It is the part of the nervous system that controls all action - the brain and spinal cord process all of the information from the peripheral nervous system.
  • Question 4

What does the peripheral nervous system do with electrical impulses? Two of the statements below are correct.

CORRECT ANSWER
The nerves carry messages from the brain and the spinal cord
The messages are in the form of electrical impulses
EDDIE SAYS
Nerves make up the peripheral nervous system and carry information as electrical impulses to and from the brain and the spinal cord. They consist of motor neurones (that make things move) and sensory neurones (that carry information to the CNS).
  • Question 5

Tick two sentences that describe functions of the nervous system.

CORRECT ANSWER
Reflex actions to prevent us from harming ourselves
Voluntary actions, where we think about something and then do it
EDDIE SAYS
The nervous system can perform voluntary actions, which we think about before doing and reflex actions, which happen fast and automatically. They also perform reflex actions that happen quickly and automatically without you thining about it.
  • Question 6

Tick three of the actions that you think are reflex actions.

CORRECT ANSWER
Knee jerk reaction
Taking hand away from a sharp object
Eye pupils get smaller in bright light
EDDIE SAYS
Pupils get bigger in dim light to enable sight, but smaller in bright light, as light is abundant and we can see easily, but also to protect the eyes from too much light.
The knee jerk reaction is when the doctor taps us below the knee to check our reflexes. Like when you touch a hot plate, touching a sharp object by mistake triggers a reflex response to avoid hurting yourself.
  • Question 7

Complete the sentence by writing the missing words in the boxes in the table below:

 

Sensory neurones carry impulses ___A___ from a sense organ, whereas motor neurones carry impulses to an ______B_____.

CORRECT ANSWER
 Missing Words
A
B
EDDIE SAYS
Sensory neurones carry impulses away from a sense organ, whereas motor neurones carry impulses to an effector. This is normally a muscle but can be other actions to a motor neurone.
  • Question 8

What is a synapse? 

CORRECT ANSWER
A gap between two neurones where the electrical impulse is transmitted with the aid of chemicals called neurotransmitters.
EDDIE SAYS
A synapse is a gap between two neurones where the electrical impulse is transmitted across with the aid of chemicals called neurotransmitters. This is where drugs like pain killers do their work - they stop signals from being sent across the synapse.
  • Question 9

Tick the correct definition of a relay neurone.

CORRECT ANSWER
A nerve cell that carries impulses from one part of the CNS to another
EDDIE SAYS
A relay neurone is a nerve cell that carries impulses from one part of the CNS to another. It is normally involved in autonomic reactions - but the brain is made up of billions of relay neurones.
  • Question 10

The steps of the reflex arc are listed in the correct order below. However, not all of the statements are correct. Tick the two wrong statements.

CORRECT ANSWER
The impulse is carried along a sensory neurone to the brain
A relay neurone passes the impulse from the brain to a motor neurone
EDDIE SAYS
A stimulus is picked by a receptor.
The impulse is carried along a sensory neurone to the spinal cord.
A relay neurone passes the impulse from the spinal cord to a motor neurone.
The motor neurone carries the impulse to an effector.
The effector performs its action.
The effector's response protects us from danger.
---- 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.