B17a Nervous system Flashcards
What is the function of the nervous system?
Enables humans to react to their surroundings
Coordinate behaviour
Name the organs found in the central nervous system
Brain
Spinal cord
Define the term stimulus
A change in the environment that is detected by a receptor
Name the organ that contains receptors that detect gases in the air
Nose
Name the organ that contains receptor detecting light
Eye
Name the organ that contains receptors that detect pain
Skin
Name the neurone that carries an electrical impulse from the receptor to the central nervous system
Sensory neurone
Name the type of cell shown in the picture

Motor neurone
What is the function of the CNS?
Central nervous system
Coordinates the response to a stimulus
What passes along the neurones in the nervous system?
Electrical impulses
Give the sequence of events tin the nervous system
Stimulus -> Receptor -> Coordinator -> Effector -> Response
How does a stimulus lead to a response being carried out by the body?
Stimulus is converted into an electrical impulse by the receptor
Electrical impulse passes along sensory neurone to central nervous system
The CNS coordinates a response
Electrical impulse passes along a motor neurone to an effector
Effector carries out a response
What is the fucntion of the sensory neurone?
Carries electrical impulses from the stimulus to the spinal cord
Give the function of a motor neurone
Carries electrical impulses from the central nervous system to the coordinator
The diagram shows the central nervous system
Name organ A and B

A = brain
B = Spinal cord
What is a reflex action?
Automatic and rapid response
Does not involve conscious input from the brain
Why are reflex action s important?
Aid survival by preventing damage to the body
Name two effectors
Muscles and glands
What is the function of the motor neurone
Carries an electrical impulse from the central nervous system to the effector
Name the gap between 2 neurones
Synapse
Name the type of neurone found in the coordinator
Relay neurone
How does the electrical impulse cross the synapse/
A chemical is released from the first neurone.
The chemical diffuses across the synapse
An electrical impulse starts in the next neurone
Name the organ that detects sound waves
Ear
Name the three neurones found in the nervous system
Sensory neurone
Relay neurone
Motor neurone



