- Define and explain Messages Along Nerves in your own words
- Use key terms such as neurotransmitter accurately
- Apply what you have learned to new examples and questions
- Avoid the common mistakes learners make with this topic
This lesson focuses on Messages Along Nerves: follow an electrical signal racing along a neuron and jumping the synapse as a chemical message.
Follow an electrical signal racing along a neuron and jumping the synapse as a chemical message.
Key ideas
Neurons are the brain's wiring
Each neuron has branchy dendrites that collect signals, a cell body that processes them, and a long axon that fires the message onward. When the signal reaches the end of the axon, neurotransmitter chemicals carry it across the synapse to the next neuron. Everything you think, feel and do is built from patterns of these tiny handoffs, happening millions of times a second.
Learning builds stronger bridges
When you practise something, the synapses involved fire together repeatedly, and the connections get faster and stronger — 'neurons that fire together, wire together', as psychologist Donald Hebb proposed. That is why a times table you rehearse becomes automatic. The brain also prunes away connections you rarely use, so regular practice keeps your most useful pathways in top shape.
Key term — neurotransmitter: A chemical messenger that carries a signal across the synapse from one neuron to another.
What happens at a synapse?
The electrical signal reaches the end of the axon, and neurotransmitter chemicals carry the message across the tiny gap to the next neuron.
Answer: The electrical signal reaches the end of the axon, and neurotransmitter chemicals carry the message across the tiny gap to the next neuron.
- Bigger brains mean cleverer people Brain size does not determine intelligence; what matters far more is the pattern and strength of the connections between neurons.
- We only use 10% of our brains Brain scans show we use virtually all of our brain, just not all at once — different parts switch on for different jobs. The 10% claim is a myth.
Practice
A nerve cell that carries messages. Its parts are dendrites (collect signals), the cell body, and the axon (sends the signal on).
Repeated firing strengthens the synapses involved ('neurons that fire together, wire together'), so the pathways become faster and the playing becomes automatic.
Cerebrum — thinking and memory; cerebellum — movement and balance; brain stem — automatic jobs like breathing and heartbeat.
False — it is a myth. We use virtually all of our brain, with different regions active for different tasks.
Quick check
Which of these best defines "neurotransmitter"?
Your friend says they are 'too old to learn' the guitar at 14. What would you tell them, using what you know about the brain?
- Messages Along Nerves: follow an electrical signal racing along a neuron and jumping the synapse as a chemical message.
- Neurons are the brain's wiring: Each neuron has branchy dendrites that collect signals, a cell body that processes them, and a long axon that fires the message onward.
- neuron: A nerve cell that carries messages around your nervous system; your brain contains around 86 billion of them.
- Watch out for: bigger brains mean cleverer people