5.2 Human Nervous system Flashcards
What is the function of the nervous system?
The nervous system allows the body to react to its surroundings and coordinate an appropriate response
How does a stimulus lead to a response being carried out by the body?
Stimulus is converted into an electrical impulse by the receptors.
The electrical impulse passes along sensory neurones to the central nervous system (CNS).
The CNS coordinates an appropriate response and an electrical impulse is sent along motor neurones to the effector, which carries out the response.
What sequence of events describes how the nervous system works?
Stimulus - receptor - coordinator - effector - response
What is a reflex action?
A reflex action is an automatic and rapid response which does not involve and conscious input from the brain
Why are reflex actions important?
aid survival by preventing harm to the body.
Describe how a reflex action occurs via a reflex arc.
The stimulus is detected by a receptor.
An electrical impulse passes along a sensory neurone to the spinal cord (Part of the CNS)
At a synapse between a sensory neurone and a rely neurone, a chemical diffuses across the gap and stimulates a new impulse which passes along the relay neurone.
The same process occurs at a synapse between a relay neurone and a motor neurone
At the effector, an appropriate response is carried out.
What is the difference between a reflex action occurs via a reflex arc.
Within a reflex pathway, the coordination centre is a relay neurone found in the spinal cord/unconscious parts of the brain. In a conscious pathway, the coordination centre is in the conscious part of the brain.
