• What does it mean by the membrane being polarised?
• what is the resting potential maintained by?
• what happens first at resting potential (what is transported)?
• why is the movement of sodium ions limited, but not potassium ions?
• what is there a high concentration of in the tissue fluid and why?

Action potential

• What causes sodium to be transported into the neurone?
• What does sodium entering the neurone cause?
• What is the process as described above called?
• draw out a graph of the action potential in a neurone
• What does the change in membrane potential (from the energy from the stimulus) further cause?
• What happens after the process above?
• What is the refractory period?
• What is the all or nothing principle?