Topic 5 - Nervous System Flashcards
What is a stimulus?
A change in your environment that requires a response. e.g Light, sound, touch, pressure, pain, chemical or temperature.
What do the receptors do?
Detect the stimulus or change in environment.
What happens after the receptors?
Receptors send messages to the CNS via the sensory neurone.
What makes up the central nervous system?
The brain or spinal cord
What is an effector?
Muscles or glands that bring about a response.
What do the muscles and glands do in response to stimuli?
Muscles contract and glands secrete chemical substances(hormones).
What is a sensory neurone?
A neurone that carry information from the receptors to the CNS.
What is a relay neurone?
Neurones that carry impulses from the sensory neurone to the motor neurone.
What is a motor neurone?
Neurones that carry information from the CNS to the effectors.
What is the nervous system?
It is a system that allows you to react to your surroundings.
What is reaction time?
The time it takes for an effector to respond to a stimuli
What are the steps taken by a reflex arc
Stimulus –> Receptor –> Sensory neurone –> Relay neurone –> CNS –> Relay neurone –> Motor neurone –> Effector –> Response
How are nerve signals transferred across a synapse? (2 marks)
Chemicals diffuse across a synapse
They set off a new electrical impulse to the next neurone
What is a reflex arc?
The passage of information in a reflex
Alcohol is a depressant. How does it affect the reaction time?
Reaction time will be slower
Nerve signals take longer to travel around the body
