A | B |
Stimulus | Detected by a receptor |
Receptor | Detects a stimulus |
Neurone | Proper word for a nerve cell |
Impulse | Electrical signal carried by a neurone |
Transduce | Change one form of energy into another |
Taste buds | Detect chemical |
Eyes | Detect light |
Ears | Detect sound |
CNS | Where sensory signals are processed |
Effector | Muscle or glands |
Response | What an effector 'does' |
Focus light | What the cornea and lens do |
Cornea and lens | Transparent parts of the eye which focus light |
Iris | Muscle which controls size of pupil |
Pupil | Hole which lets light into the eye |
Cone | Detects the colour of light |
Rod | Detects light and dark |
Fovea | Where cones are most concentrated |
Optic nerve | Carries nerve impulses from the retina |
Blind spot | Hole in the retina which the nerves pass through to the optic nerve |
Close to you | Where objects are if the lens is very fat |
Far away | Where objects are if the lens is very thin |
Muscle | What the iris is made of |
Sensory neurone | Takes impulses from a receptor to the CNS |
Motor neurone | Takes impulses from the CNS to muscles or glands |
Reflex | An automatic (involuntary) response to a stimulus |
Reflex arc | The pathway of nervous impulses that make a reflex happen |
Rapid response | The reason reflexes protect the body so well |
Spinal cord | The part of the CNS which isn't the brain |
Conscious thought | Not involved in a reflex |
Fatty sheath | Surrounds the axon of a nerve cell to make it faster |
Fat | What the sheath round an axon is made of. It electrically insulates it. |
Axon | The long part of a motor neurone which carries impulses. |
Middle | Where the cell body is in a sensory neurone |
Synapse | A nerve cell junction |
Chemicals | What carries messages across the gap (synapse) between neurones |
Drugs | Change the way synapses work, by blocking or exciting them |
Alcohol | Legal drug that slows synapses down |
Nicotine | Legal drug that stimulates synapses (makes them work too fast |
Solvent | Messes up synapses, found in glue. Abuse of it regularly kills people even on their first go. |