An electrical impulse cannot travel across a gap so another mechanism needs to
be used. When the impulse reaches the end of the neuron chemicals called
neurotransmitters are released into the gap. These diffuse across and bind to
receptors in the next neuron which sets off a new impulse.
Key Stage 4 –
Nervous models
Pupil worksheet
brain
A model network
To drive from your house to a town hundreds of
kilometres away, you will have to travel on many
different roads. In order for the road network to
function roads have to join up with each other.
spinal
cord
neurons
This is a good model of your nervous system. It is a
complex network of neurons. In order for impulses
to get from one place to another they have to be
able to pass from neuron to neuron.
The gaps between neurons are called synapses
The nervous system
There is a small gap where the end of one neuron joins with another. Professor
Charles Sherrington, who worked at the University of Oxford in the early 20th
century, named this a synapse.
Drugs and toxins can interfere with synapses
Ecstasy (MDMA) works by
increasing the amount of the
neurotransmitter serotonin
in the brain. It blocks
serotonin re-uptake pumps
on the pre-synaptic neuron.
High levels of serotonin
induces feelings of euphoria.
Botulinum toxin (botox) is
made by bacteria and causes muscle paralysis by blocking impulses between
motor neurons and muscles. It does this by binding to the neurotransmitter
receptor on muscles.
Your task
You are going to use a model to create a stop-capture animation of what happens
at a synapse.
What to do
1. Work in a pair or small group.
2. Research what happens at a synapse. Use textbooks, the internet and the
images supplied on this worksheet.
3. Decide what materials you are going to use to create your model. Plan a
simple storyboard for your animation on paper.
4. Use a tablet/phone or camera to create the animation.
http://www.oxfordsparks.net/video/youve-got-nerve
Motor neuron
Close-up of synapse
Direction of
impulse
Muscle cells
A diagram to show two neurons and a close-up view of the
synapse in between them
http://www.oxfordsparks.net/video/youve-got-nerve
The connection between a motor neuron and a muscle is
known as a neuromuscular junction. Impulses from the
neuron are transmitted to the muscle cells by the
movement of neurotransmitters across a synapse.