Please enable JavaScript.
Coggle requires JavaScript to display documents.
The Nervous System (Sense organs (Eyes: light receptors detect light…
The Nervous System
Neurones
Sensory Neurones: the nerve cells that carry signals from the receptors to the central nervous system.
Relay Neurones: the nerve cells that carry signals from the central nervous system to the effector muscles or glands
-
Sense organs
-
-
-
Skin: receptors detect touch, pressure, pain and temperature change.
-
a stimulus is a change in your environment which may need to react to. all your sense contain different receptors. receptors are groups of cells that detect electrical impulses.
Stimulus could be light, sound change in temperature,
Synapses and Reflexes
synapses: the connection between two neurones is called a synapse. the nerve signal is taken across the gap by chemicals. these chemicals set off a new electrical signal in the next neurone.
Reflexes: reflexes are automatic responses to certain stimuli they just happen. reflexes are much quicker than normal because you don't have to think about them. they help to stop you injuring yourself e.g bright light makes your pupils smaller to prevent eye damage.
- cheeky bee stings your finger. bee sting is detected by pain receptors on skin.
- impulses are sent along a sensory neurone to the CNS
- impulses reach a synapse between the sensory neurone and a relay neurone. Here chemicals are released causing impulses to be sent along the relay neurone.
- impulses reach a synapse between the relay neurone and a motor neurone. chemicals are released, which cause impulses to be sent along the motor neurone.
- impulses are sent along the motor neurone to the effector. in this case its a muscle which cintracts to move your hand away from the bee