S4.5.1 For the adult
The nervous system
You touch something hot. How does the news get to your brain, and how does your hand get the order to move?
What this chapter teaches
A receptor starts an impulse. A sensory neurone carries it to the brain or spinal cord, and a motor neurone carries the order to an effector. Neurones meet at synapses, where a chemical crosses the gap. The brain has a cerebrum, a cerebellum and a medulla with different jobs.
Three questions to ask
There is no one right wording. Listen for the idea.
- What happens, step by step, between a pin touching a finger and the finger moving?
- How does a message cross the gap between two neurones?
- What does the medulla do, and why does it keep working when we sleep?
After the chapter, the learner can
- Trace a message from a receptor through the brain to a muscle
- Name the main parts of the brain and their jobs
What they copy into their notebook
Stimulus, receptor, sensory neurone, brain or spinal cord, motor neurone, effector, response. A chemical crosses each synapse. Cerebrum thinks, cerebellum balances, medulla keeps heart and breathing going.