Graded Potentials + Synapses Flashcards
what is an AP
all or none event
profile of voltage change and fixed time
propagates along axon
positive feedback
what is a graded pot
local change in mem pot
vary
fizzle out and nerve end
what is a triggering event for a grad pot
synaptic - post syn mem
receptor - action of stimulus
mech, them thermal gated channel
what is transduction
convert mechanical stimulus to electrical response
what is the trigger for AP
deep to threshold (-50mV)
what si the trigger for grad pot
stimulus, neurotransmitter
what is the ion move for AP
Na the K though voltage gated channels
what is the ion movement for grad pot
Net move of Na, K, Cl or Ca
what is the magnitude of an AP
all or none frequency
what is the magnitude for grad pot
she of potential changes
what is the duration of AP
fixed
what is the duration of grad pot
variable
what si the propagation of AP
sep regen propagation
what is the propagation of grad pot
decays with distance
are there refractory periods for AP and grad pots
AP - yes
grad pot - no
what is the direction of potential change for an AP
deep then hyper polarisation
what is the director of potential change for a grad pot
deep or hyper polarisation
where does AP and crd pots occur
AP - voltage gated channels
grad pots - receptors and post-synapse
what do grad pot receptors do
transduction at nerve ends via channels (mechanical, thermal, capsaicin- spice)
what are synapses
one way relay stations post or pure synaptic
plasticity
synapses ar usually chemical such as
neurotransmitters glutamate GABA Ach serotonin Noradrenaline
what is EPSP
excitatory post-synaptic potential
what si the sequence of graded pot
gated sun potential
AP initiation
AP propagation
what is temporal summation
propagation from one neurons
what is spatial summation
propagation form multiple neurones
what is IPSP
inhibitory post- synaptic potential
what happens with IPSP
hyperpolarisation
inhibit neurotransmitter GABA
what is presynaptic inhibition
no direct effect on post synaptic mem
decrease neurotransmitter release
axo-axonal synapse
