Nervous System Flashcards
Why do we need a nervous system?
It enables humans to react to their external surroundings and coordinate behaviour response.
What are the changes in your internal and external surroundings are known as?
Stimuli
What are the cells called that detect these changes?
Receptors
What is the central nervous system made up of?
Brain and spinal cord
How is information carried around the Nervous System?
Electrical impulses
How fast does the nervous system transmit information?
1 to 120 meters per second
What is the travelling of impulses called?
Neurotransmission
How does the structure of dendrons and axons aid their function?
Long to allow for fast neurotransmission over long distances
What is the myelin sheath?
A fatty layer around the dendron and axon
Name 2 ways the myelin sheath supports neurotransmisssion.
- It electrically insulated the neurone from neighbouring neurones in a nerve.
- It stops signals losing energy and increases the speed of neurotransmission.
5 steps of the path of a nervous response.
Stimulus
Sensory receptor
Sensory neurone
CNS
Motor neurone
Effector organ
Why do we need reflexes?
To avoid danger or harm
Are reflexes automatic or conscious?
Automatic
What is the purpose of reflexes (give examples)
To take care of basic functions.
E.g breathing, moving food through digestive system
How is the path of a neurone response different to the path of a reflex response?
Doesn’t go via the brain it skips it
Label the 5 steps of the path of a reflex response
Stimulus
Sensory receptor
Sensory neurone
Relay neurone
Motor neurone
Effector
What are the 3 neurons involved in a reflex action?
Sensory neuron
Motor neuron
Relay neuron
What are the 3 steps involved in
neurotransmission at the synapse?
- Electrical impulse arrives at the synapse causing release of neurotransmitters
- The neurotransmitters diffuse across the synapse
- The neurotransmitter binds the the receptors on the next neurone and triggers an electrical impulse.
