8.3

Question 1

Describe resting potential (distribution of ions/charge/which voltage gates are open)

Answer 1

Outside axon - high Na+ conc, low K+ conc, relatively positive concentration
Inside axon - low Na+ conc, high K+ conc, relatively negative concentration

Question 2

Describe depolarisation (distribution of ions/charge/which voltage gates are open)

Answer 2

Stimulus causes Na+ channels to open, once -55mV is reached, all Na+ channels open and sodium moves into axon, causing spike in relative positive charge in axon

Question 3

Describe repolarisation and hyperpolarisation (distribution of ions/charge/which voltage gates are open)

Answer 3

• K channels open and K moves down concentration gradient , restores positive outside and negative inside but sudden movement causes over negative (more than -70mV)