20-21 - The Nervous System Flashcards
What is an axon?
The long fibre of the neurone insulated by a fatty sheath
What are the branches of the neurone called?
Dendrons (they branch into dendrites)
What do receptors do?
Receptors in sense organs respond to stimuli
Which sense organ’s stimulus is light?
The eye
What is the stimulus of the skin?
Touch, temperature, pressure
What is the tongue and nose’s stimulus?
Chemicals (in food and drink or the air)
What are the ear’s stimuli?
Sound
Balance
What are effectors?
Muscles and glands that produce responses to stimuli
What is a muscle contracting to move and arm an example of?
An effector in action
Stimulus -> Receptor -> ______ -> Relay neurone -> ______ -> ______ -> Response
Sensory neurone, motor neurone, effector
What happens in the reflex arc when something hot is detected?
Pain receptor stimulated
Impulses travel along sensory neurones
Impulses pass a synapse to the relay neurone
Pass a synapse to motor neurone
Impulse makes muscle contract
What is the synapse?
The gap between neurones which nerve signals diffuse across
What is the CNS?
Where information from sense organs is sent
Brain and spinal cord
What are sensory neurones?
Nerve cells that carry impulses from receptors to CNS
What are relay neurones?
Nerve cells that carry signals from sensory neurones to motor neurones
