Synapses Flashcards
gaps between neurons called
synapses
tips of axon terminals are called
synaptic end bulbs
space between synaptic end bulbs and next neurone in chemical synapses is the
synaptic cleft
the nerve impulse is carried across the synaptic cleft by
neurotransmitters
nerve messengers
in electrical synapses connections between synaptic end bulbs and the next neurone are
gap junctions
synapse stages 1
nerve impulse arrives at
end bulb
synapse stage 2 depolarisation phase causes
calcium channels to open
sending calcium into synaptic bulb
synapse stage 3
increase in concentration of calcium ions causes
exocytosis of synaptic vesicles
neurotransmitters are released into synaptic cleft
synapse stage 4
neurotransmitters diffuse across the synapse and
bind to receptors on post-synaptic neuron
opens ion channels on post-synaptic neurone allowing ions to flow across the meambrne
synapse stage 5
the change in ions creates a
post-synaptic potential
this triggers an action potential in post-synaptic nerve
chemical messenger used to create synaptic transmission
neurotransmitter
4 groups neurotransmitters
amino acids - taurine
peptides - vasopressin
monoamines - dopamine
unique molecules - ACTCH
neurotransmitters which cause the ion channels to open - called
excitatory
neurotransmitters cause the ion channels to close are
inhibitory
following a nerve impulse, neurotransmitters need to be removed for the process to be able to
start again
