Sense Organs (Cambridge International IGCSE Biology)
Exam board Cambridge International · IGCSEUpdated 2026-08-28
Sense organs as receptors
Spec point —
14.1.5· Describe sense organs as groups of receptor cells responding to specific stimuli: light, sound, touch, temperature and chemicals
- Receptors are groups of specialised cells
- They detect a change in the environment and stimulate electrical impulses in response
- Sense organs contain groups of receptors that respond to specific stimuli
| Sense organ | What it is sensitive to | Sense |
|---|---|---|
| Skin | Sensitive to pressure, heat and cold (temperature) and pain | Touch and temperature |
| Tongue | Sensitive to chemicals in food and drink | Taste |
| Nose | Sensitive to chemicals in the air | Smell |
| Ear | Sensitive to sound and movement | - Hearing - Balance |
| Eye | Sensitive to light | Sight |
- Once the receptor cell in the sense organ has been stimulated, it generates an electrical impulse
- This is passed on to a sensory neurone which carries the impulse to the central nervous system
- Here a response will be decided on and the impulse will be passed to a motor neurone (via a relay neurone)
- The motor neurone carries the impulse to the effector (muscle or gland)
- The effector carries out the response
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