The Nervous System Flashcards
What are the 5 sense organs?
Nose, eyes ears mouth skin
Define receptors.
Group of cells that are sensitive to a stimulus, they change stimulus energy into electrical impulses.
What is the CNS comprised of?
Brain and spinal cord
What happens in the CNS?
Where all the information from the sense organs is sent, and where the reflexes and actions are coordinated.
What do neurones do?
Transmit electrical impulses to and from the CNS
Where are the instructions from the CNS sent to?
The effectors ( muscles and glands), which respond accordingly.
What are the 3 types of neurones?
Sensory, relay and motor neurones
What is the job of the sensory neurones?
They carry information (electrical impulses) from the receptors in the sense organs to the CNS
What do the relay neurones do?
Carry signals from the sensory neurones to motor neurones.
What are the motor neurones?
The neurones that carry electrical impulses from the CNS to the effectors
What is the job of the nervous system?
To detect stimuli so we can coordinate behaviour
How does a synapse transfer a nerve signal?
> it is transferred by chemicals which diffuse across the gap
> these set off a new electrical signal in the next neurone
What is a reflex?
An automatic response to certain stimuli
> can prevent injury
What is a reflex arc?
The passage of information in a reflex, (from receptor to effector)
List the steps of a reflex arc.
> stimulus >receptor >sensory neurone >relay neurone >motor neurone > effector >response
