the nervous system Flashcards
what is the CNS made up of
the brain, nerve cells and spinal cord
what is a stimulus
a change inside or outside the body that triggers a response
what do receptor cells do
covert stimulus into an electrical impulse
where does the electrical impulse travel along
the sensory neurone, to the CNS (info is processed and appropriate response coordinated)
what carries out the action
effectors
what is neurotransmission
travelling of an impulse
what is neurotransmission
travelling of an impulse
why are axons and dendrons generally long in sensory neurones
to allow fast neurotransmission over long distances
what does a myelin sheath do
electrically insulates a neurone from neighbouring neurones, stopping the signal losing energy
makes the impulse ‘jump’ along the cell between the gaps in the myelin and so speeds up neurotransmission over long distances
what is a synapse
gap between two neurones
how do neurotransmitters move across the synapse
impulse reaches an axon terminal and a neurotransmitter is released into the synapse
neurotransmitter diffuse across the gap and are picked up my receptors in the next neurone
new electrical impulse is generated in the next neurone
how do synapses affect neurotransmission
slow down neurotransmission as it takes time for neurotransmitters to diffuse across
what do synapses allow
generation of fresh impulses of the same strength as before
