PHYSIOLOGY - nerve conduction and synaptic transmission Flashcards
how do myelin sheaths work
insulator = conductor = AP moves more rapidly
what is the node of ranvier
the unmyelinated part of an axon
not covered by a myelin sheath
how does the node of ranvier increase AP speed
it allows APs to leak
where is the synaptic cleft between
the pre synaptic and post synaptic membranes
what structure stores and releases neurotransmitters for synapse
vesicles
what things are lines up on the post synaptic membrane
receptors
what neurotransmitter causes an excitatory synapse
glutamate
what neurotransmitter causes an inhibitory synapse
GABA or glycine
what ‘potential’ does an excitatory synapse cause
e.p.s.p. (excitatory postsynaptic potential)
what ‘potential’ does an inhibitory synapse cause
i.p.s.p. (inhibitory postsynaptic potential)
what is the NET accumulatio nof i.p.s.p and e.p.s.p called
spatial summation
what is it called when just one e.p.s.p causes an AP (action potential)
temporal summation
what is the result of spatial summation with NET i.p.s.p
no AP transmission
what is the result of spatial summation with NET e.p.s.p
AP transmission
what is the normal membrane resting potential voltage
-70mV
what voltage is membrane depolarisation
-40mV
what voltage is membrane hyperpolarization
-80mV
what happens for depolarization to occur
Na+/Ca+ influx
OR
Cl- efflux (exit)
what type of conduction is facilitated by the node of ranvier
saltatory conduction
what happens for hyperpolarization to occur
Cl- influx
K+ efflux (exit)
