The Nervous System Flashcards
Your nervous system allows you to r________ to your surroundings
react
What is a stimulus?
A change in your surroundings
List examples of stimuli
Light Sound Chemicals Changes in position Temperature Pressure Pain Touch
What detects stimuli?
receptors
Where are receptors located in the human body?
Tongue Eyes Ears Nose Skin
What is meant by the central nervous system?
The brain
Spinal cord
Neurones (nerve cells)
How is information sent around the body?
Electrical impulses
The gap between 2 nerve cells is called a
synapse
How are messages passed between neurones
By a chemical (neurotransmitter)
Why do we have reflex actions?
To protect us
Describe a reflex action
Fast
Automatic
Explain the stages involved in a reflex action when being stung by a bee.
Stimulus (pain)
Receptor (in skin)
Sensory Neurone (carries electrical impulse)
Relay Neurone (carries electrical impulse)
Motor Neurone (carries electrical impulse)
Effector (muscle in arm)
Response (muscle contracts moving arm)
Where in the body are light receptors found?
The eyes
Where in the body are balance receptors found?
The ears
Where in the body are sound receptors found?
The ears
Which two types of receptor do the ears contain?
Sound receptors
Balance receptors
Which type of receptors does the tongue contain?
Chemical receptors
Which type of receptors does the nose contain?
Chemical receptors
Which type of receptors are found in the skin?
Pressure
Temperature
Pain
A stimulus is detected by a
receptor
A receptor passes an electrical impulse to a
sensory neurone
A sensory neurone passes an electrical impulse to a
relay neurone
A relay neurone passes an electrical impulse to a
motor neurone
A motor neurone passes an electrical impulse to an
effector
An effector can be either a _____ or a _____
muscle
gland
Muscles and glands are both
effectors
What is the response of a muscle?
It contracts
What is the response of a gland?
It releases a hormone
Explain what happens during a conscious action e.g. seeing a cat in the road and stepping on car brakes.
Stimulus - light reflecting off cat.
Receptors - in eyes detect light from cat.
Sensory neurone - carries electrical impulse to…
Central nervous system which carries an impulse to…
Motor neurone - carries impulse to…
Effector (muscle in foot)
Response - step on car brakes.
What effect does alcohol have on the nervous system?
It slows it down.
