Question

訪客

有人可以解釋一下這張圖嗎ಥ_ಥ

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

Answer 1

微微米

不曉得現在回你是否有幫到你........

這是在講膜動作電位的發生：
上下2個圖要搭配看：上面是膜電位 ，中間是膜上Na-K離子通道的變化，下面是膜內外相對滲透壓。
左上是rest尚未產生動作電位去極化以前。
在1-2毫秒產生去極化：就是左下的PNa>>PK....
1.一開始是Ek是因爲K離子通道會leak（漏到膜外）
2.當刺激過閾值（threshold),Na通道開啟，往膜內跑， 3.去極化造成Na通道開啟更多。
4.關閉Na通道，延遲開K通道，停止膜的去極化。

去極化之後到回rest電位 3-15毫秒：
5.開啟K通道，使膜再極化，回到負的電位
6.K通道比較慢關閉，導致膜電位朝EK再極化，而且Na通道也關閉了
7.關閉K通道後回到rest電位。

你可以參考這個網站
https://highscope.ch.ntu.edu.tw/wordpress/?p=6906