The Nervous System
Sense organs detect stimuli
- You have 5 different sense organs: eyes, ears, tongue, skin and nose.
- They all contain different receptors. Receptors are a group of cells which are sensitive to a stimulus. They change stimulus energy to electrical impulses.
- A stimulus can be light, sound, chemical, touch, pressure, pain, change of position or temperature.
- Light receptors - sensitive to light. These cells have a nucleus, cytoplasm and a cell membrane like most animal cells.
- Sound receptors - sensitive to sound.
- Balance receptors - sensitive to change in position.
- Smell receptors - sensitive to chemical stimuli.