# Introduction

> Humans respond to changes in their environment using two systems: the nervous system, which sends fast signals along nerves, and the endocrine system, which sends slower messages as hormones in the…

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## Full notes

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## More in RESPONDING TO THE ENVIRONMENT (Humans)

- [Human nervous system](https://www.hlayiso.com/grade-12/life-sciences/notes/responding-to-the-environment-humans/human-nervous-system) — Next section
- [All RESPONDING TO THE ENVIRONMENT (Humans) sections](https://www.hlayiso.com/grade-12/life-sciences/notes/responding-to-the-environment-humans)

## Frequently asked questions

### What will I learn in "Introduction"?

This section covers Introduction as part of RESPONDING TO THE ENVIRONMENT (Humans) in Grade 12 Life Sciences. You'll find clear explanations, worked examples, and key definitions aligned to the CAPS curriculum.

### Is this section aligned with the CAPS curriculum?

Yes. All notes on Hlayiso, including "Introduction", are written against the official CAPS curriculum and ATP for Grade 12 Life Sciences.

### What should I study after "Introduction"?

Continue with the next section in RESPONDING TO THE ENVIRONMENT (Humans), or test your understanding with the interactive quiz linked to this section.

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