Depolarization opens voltage-gated Na+ channels, increasing membrane permeability to Na+ and causing further depolarization (action potential). Repolarization occurs when Na+ channels close and voltage-gated K+ channels open.
تؤدي إزالة الاستقطاب إلى فتح قنوات الصوديوم المبوبة بالجهد، مما يزيد من نفاذية الغشاء للصوديوم ويسبب إزالة استقطاب إضافية (جهد الفعل). يتم إعادة الاستقطاب عن طريق إغلاق قنوات الصوديوم وفتح قنوات البوتاسيوم المبوبة بالجهد.
| Front | creating action potential process |
|---|---|
| Back | not transmitting impulse so at resting potential, some K+ channels open but voltage gated Na+ channels closed - energy of stimulus causes voltage gated Na+ channels to open, making membrane permeable to Na+ and so Na+ moves down electrochemical gradient, making inside axon less negative, this change in charge causes more Na+ channels to open - Now p.d is at 40mV, so VGNa+ channels close and VGK+ channels open, so K+ diffuse out down electrochemical gradient, making inside axon more negative and eventually more negative than resting pot - now VGK+ channels close, Na/K pump pumps Na+ out membrane and K+ into cytoplasm, so axon repolarised |
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