Zusammenfassung der Ressource
The Nervous System
- You have five sense organs.
- They all contain different RECEPTORS-groups of cells which are sensitive to specific stimuli.
- A STIMULUS can be anything from
- Light
- Sound
- Pressure
- Chemical
- Change in position or temperature.
- RECEPTORS work by changing stimulus energy to electric impulses.
- The five sense organs and the receptors they contain.
- Eyes-Light receptors
- Ears-Sound and Balance receptors.
- Nose-Smell receptors-sensitive to chemical stimuli.
- Tongue-taste receptors for bitter, salt, sweet, sour plus savoury eg Monosodium Glutamate.
- Skin-sensitive to touch, pressure and temperature change.
- The Central Nervous system
- Consists of Brain and spinal cord ONLY.
- Where all information from organs is sent & where reflexes and actions are co-ordinated.
- Neurones (nerve cells)
- Transmit the information (as electric impulses) very quickly to and from the CNS.
- Sensory Neurones-The nerve cells that carry signals as electrical impulses from the receptors in sense organs to CNS
- Motor Neurones: Nerve cells that carry signals to the effector muscles or glands.