The Nervous System Flashcards
What is the nervous system’s purpose?
To protect organisms from harm by responding to changes in the environment. It does this by coordinating communication between different parts of organisms.
What is the nervous system made up of?
- The brain
- The spinal cord
- The neurones (nerve cells)
Where do nerve cells carry electrical impulses?
Between receptors, the central nervous system
What is the effectors’ job?
Effectors bring about actions in response to change in the internal or external environment. Such actions include muscles contracting and glands secreting hormones.
What are synapses?
Synapses are gaps between neurones and can be found at each junction of a reflex arc.
What are neurotransmitters?
Neurotransmitters are chemicals that diffuse across synapses and bind to receptors on the next neurone.
What is a reflex action?
A reflex action is an unconscious response that allows a person to respond to a dangerous situation automatically and rapidly via a reflex arc.
What are the components of a reflex arc?
- Stimulus
- Receptor
- Neurones
- Effector
- Response
What are the three types of neurone?
- Sensory
- Relay
- Motor
What does the sensory neurone do?
Carries the signal in the form of an electrical impulse to the central nervous system.
What does the relay neurone do?
Relays the electrical impulse from the sensory neurone to the appropriate motor neurone.
What does the motor neurone do?
It is another type of nerve cell that carries the electrical impulse from the CNS to an effector.
