b6-5 synapses

1.

Homework
Go to the following site and research the effect of different
drugs on synaptic transition
– copy this into your planners/exercise books!
http://outreach.mcb.harvard.edu/animations/synapse.swf
Summarise the effect of one of the drugs from this
site in your own words.

2.

18/11/2025
B6-5
SYNAPSES
Objectives:
MUST – describe the structure and function of a synapse - C
SHOULD – explain how addiction can be caused by the effect
of drugs on the synapses - B
COULD – Design a model to show how an impulse is
transmitted across a synapse - A/A*

3.

Skin
Touch
receptor
Sensory
neuron
Spinal
cord
Electrical
impulse
Muscle
(effector)
Motor
neuron
Relay
neuron
There are THREE neurones in this diagram.
How does the nerve impulse travel from one neuron
to the next?

4.

Don’t take notes
LISTEN
– but
to the next few slides –
you will have a worksheet to fill in.

5.

Neuronotransmitter stored
in tiny packages called
vesicles
Presynaptic
Neurone
Synapse
20nm
(nanometers)
wide
Receptor
molecules
Postsynaptic
Neurone

6.

1.
Nerve impulse arrives at
the synapse
IMPULSE
2.
Chemical messenger (a
neurotransmitter) is released into
the synapse.

7.

3.
Neurotransmitter diffuses
across the synapse
4. Neurotransmitter
binds with a
receptor on the
membrane of
the postsynaptic neuron
IMPULSE
5.
Binding of neurotransmitter
to receptor stimulates impulse in
postsynaptic neuron

8.

https://www.youtube.com/watch?v=6X Handouts
sMNd_yXug

9.

Using information from the following slide answer
the following questions.
1. What plant extract is used in poison darts – and
why is it such an effective poison?
2. Why was strychnine the poison of choice for
spurned Victorian house-wives?
3. What chemical gives us a natural high?
4. How do anti-depressants work?

10.

11.

Can you match the key words to their definitions?
Prozac
Synapse
Receptor
Serotonin
Ecstasy
Nanometre molecule
A tiny gap between neurones that transmits
nerve impulses from one neurone to the next
One millionth of a millimetre
A chemical released by one type of synapse in
the brain – it stimulates feelings of pleasure
An anti-depressant – it works by raising
serotonin levels in the brain
Molecules in the membrane of a neurone which
detect chemicals released by sensory neurones
A drug which works in a similar way to Prozac –
it may, however, destroy synapses causing
depression and anxiety