1. 1.The brain can only understand electrical signals 2.Receptors in the eyes change light into electrical signals 3.Receptors in the ears change sound into electrical signals 4.The iris can change the size of the pupil depending on light intensity Sense Organs Sense organs

3. The Eye

6. Iris and Pupil

7. Vibrations to the Ear

8. The Ear

11. 1.The nervous system transports electrical impulses from receptors to the central nervous system (brain and spinal cord) and then back to effectors 2.There are three types of neurone 3.The reflex arc allows us to make emergency decisions in less time The Nervous System

12. Receptor cells

13. Neurones Neurones

14. Neurones

15. The Nervous System

16. Reflex actions

17. Wordsearch Wordsearch

18. Quiz Quiz