The big idea: The central nervous system is the brain and the spinal cord. The brain is the body's central information integration organ: it combines information arriving from many inputs at once, compares it with what has been learned and remembered, and decides on one coordinated response.
The points to remember
- The CNS is the brain and the spinal cord.
- The brain receives information from many inputs at once.
- It combines (integrates) them into one picture.
- It uses learning and memory from past experience.
- It decides on one coordinated response.
Remember it as: Many in, one out, with memory in between.
Real example: crossing a road. Before you cross, your brain combines what your eyes see (a car), what your ears hear (its engine) and what you have learned about traffic. It then sends one decision to your leg muscles: wait, or go.
Trap: The brain does not just pass signals on: it combines several inputs and uses memory before it responds. That is what makes it an integration organ.
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How it is asked: Expect a short question naming the parts of the CNS, or asking how the brain integrates information.
IB-style questionOutline[2 marks]
Outline the role of the brain as an integration organ.
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