Resting and Action Potential

• Resting potential is established through electrical chemicals inside and outside of the neurone
• Positive ions such as Na+ and K+ are kept outside of the neurone, creating a more negative environment inside the neurone at -70mv
• Negative potential is achieved through sodium-potassium pumps, involving active transport and ATP
• 2 K+ ions are actively moved into the neurone, whilst 3 Na+ ions are actively moved out, creating an electrochemical gradient to diffuse down to maintain negative potential
• Membranes are more permeable to K+ ions
• Action potential is established due to depolarisation, the membrane becoming more permeable to Na+ ions
• Stimuli stimulate sodium ion voltage gated channels to open, causing an influx of Na+ into the neurone, depolarising and sending an action potential at -55mv
• K+ ion channels are permanently open in the membrane
• As voltage increases, more gates are opened, until +40mv is reached where repolarisation occurs, closing channels and causing more K+ channels to open