Action Potentials

Question 1

Why is the resting potential of neurones closer to Kion

Answer 1

-membrane has K+ channels
-K+ are able to move down their concentration gradient

Question 2

What is the threshold potential in mV

Answer 2

~55mV

Question 3

Describe repolarisation [4]

Answer 3

-Na+ close
-K+ open
-influx of K+ down concentration gradient out of cell
-decrease in membrane potential

Question 4

Describe hyperpolarsation

Answer 4

-K+ channels are opened for too long
-K+ close
-Na/K pump works to bring membrane potential

Question 5

What is the refractory period

Answer 5

the time after an action potential where another action potential cannot occur

Question 6

What factors affect the recovery time of a Na+ channel

Answer 6

-time
-voltage

Question 7

What is VHalf

Answer 7

-the membrane potential at which half sodium channels are open

Question 8

Compare CA1 pyramidal neurones with OLM interneurones

Answer 8

-Glutamate/GABA
-Peaks at 40mV/20mV
-Threshold more hyperpolarised/less hyper polarised
-2 a subunits/ one type
-long/short refractory period
-More time in depolarised sate/ less time in depolarised state