Parts of the Brain — Psychology (Grade 11)

Define and explain Parts of the Brain in your own words
Use key terms such as neuron accurately
Apply what you have learned to new examples and questions
Avoid the common mistakes learners make with this topic

This lesson focuses on Parts of the Brain: tour the cerebrum, cerebellum and brain stem, and find out what each part does.

Definition: Parts of the Brain

Tour the cerebrum, cerebellum and brain stem, and find out what each part does.

Key ideas

Different parts do different jobs

The cerebrum, the big folded part on top, handles thinking, memory and planning. Tucked underneath at the back, the cerebellum coordinates movement and balance — it is why practice makes your football kick smoother. The brain stem, connecting the brain to the spinal cord, runs the automatic essentials: breathing, heartbeat and staying awake.

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.

Key term — neuron: A nerve cell that carries messages around your nervous system; your brain contains around 86 billion of them.

Worked example: Parts of the Brain

Name the three main parts of the brain and one job each does.

Cerebrum — thinking and memory; cerebellum — movement and balance; brain stem — automatic jobs like breathing and heartbeat.

Answer: Cerebrum — thinking and memory; cerebellum — movement and balance; brain stem — automatic jobs like breathing and heartbeat.

Common mistakes

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.
The brain stops changing after childhood The brain keeps rewiring itself throughout life as you learn — that is how adults can still learn languages and musical instruments.

Practice

What is a neuron, and what are its three main parts?

Think: branches, body, tail.

A nerve cell that carries messages. Its parts are dendrites (collect signals), the cell body, and the axon (sends the signal on).

True or false: humans only use 10% of their brains.

What do brain scans show?

False — it is a myth. We use virtually all of our brain, with different regions active for different tasks.

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?

Does the brain stop rewiring?

The brain keeps forming and strengthening connections throughout life, so practice at any age builds the neural pathways needed — 14 is definitely not too late.

What happens at a synapse?

The message changes form here.

The electrical signal reaches the end of the axon, and neurotransmitter chemicals carry the message across the tiny gap to the next neuron.

Quick check

Parts of the Brain — quick check

Which of these best defines "neuron"?

A nerve cell that carries messages around your nervous system; your brain contains around 86 billion of them.

Explain, using neurons, why practising the piano every day makes playing easier.

Repeated firing strengthens the synapses involved ('neurons that fire together, wire together'), so the pathways become faster and the playing becomes automatic.

Key takeaways

Parts of the Brain: tour the cerebrum, cerebellum and brain stem, and find out what each part does.
Different parts do different jobs: The cerebrum, the big folded part on top, handles thinking, memory and planning.
cerebrum: The large, wrinkly top part of the brain where thinking, memory and decision-making happen.
Watch out for: we only use 10% of our brains

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