A
State the names of the two parts of the central nervous system.
Brain and spinal cord
State the name given to the junction between two neurones.
synapse
Describe the role of the nervous system.
coordination and regulation of body functions
State the names of the three types of neurones.
sensory, relay, motor neuron
A boy accidentally touches a very hot object and immediately takes his hand away. In this reflex action, what is the effector?
a muscle in his arm
State the function of myelin sheath.
To insulate the axon
Define the term sensitivity.
The ability to detect and respond to changes in the internal or external environment.
Describe how voluntary actions differ from reflex actions.
Voluntary actions:
- under conscious control
- slower than a reflex action
- a specific stimulus is not required
- impulses are produced in the brain
Draw a labelled diagram of motor neuron.
Dendron - cell body - axon (+myelin sheath) - axon terminal
Describe the events at a synapse.
1. an impulse stimulates the release of neurotransmitter molecules from vesicles into the synaptic gap
2. the neurotransmitter molecules diffuse across the gap
3. neurotransmitter molecules bind with receptor proteins on the next neurone
4. an impulse is then stimulated in the next neurone