neurons

Question 1

what is the definition of membrane potential?

Answer 1

potential difference between interior of a cell and interstitial fluid beyond the membrane

Question 2

what is hyperpolarisation?

Answer 2

when the membrane potential moves away from o

Question 3

what is depolarisation?

Answer 3

when the membrane potential moves towards 0

Question 4

describe the sequence of events that lead to and follow an action potential

Answer 4

. if MP raised to approx -50mV, larger depolarisation occurs (AP)
. Threshold for sodium ion channles reached so they open, causing MP to move towards 0 as sodium ions diffuse into cell through volagte gated channel
. when MP reaches +35mV, sodium ion channels shut and volateg gated potassium ion channels open
. potassium ions leave cell
. overshoot occurs

Question 5

how does local anaesthetic work?

Answer 5

blocking sodium ion channels

Question 6

what is the funtion of the refractory period after an AP

Answer 6

neuron cannot generate another AP until 1st one has ended

Question 7

what is the fucntion of myelination

Answer 7

increase action potential comdution speed