At Resting state (1)
RO二一 PNa
說GIeSe to BR
還rom IN
At Rapid depolarization (3)
PNa
> Pr
‧Ynm closetoENa
*Yn farfrom Ek
全
晶
生
和
【
S
S
ge
g
eg
5
EE
5
三
ive membrane permeability
@ Steagy restingo membrane potentialis near
Ex Pk>Pkadue toleak K* channels.
人 euocalmembrane sbroughtio heshold
voltage by adepolarizing stimulus,
@ Curent through opening voltage-galed Na*
(hannels rapidiy depotarizes the membrane,
causing more Na* channels to Open.
Onactvation of Na" channels and delayed
opening of voltage-gated K* channels hals
membrane depolarization
@outward cumentthrough open voltage-
gated K* channels repolar2es the membrane
back toanegatve potentialL
G@ Persstent curentthrough siowiy cosing
Threshold potential voltage gated K” channels hyperpolarzes
盡 membrane toward Ex; Na* channes retum
from inactivated stale to cosed state(without
9 openno)
O@cCiosure ofvoltage-gated K" channels rsturms
the membrane potential to 8 resting value.
Voltage-gated
Na" channel
volage-oated
K'channel