Ion Permeability + Resting Potential Flashcards
1
Q
What is the membrane potential value depend on?
A
Ratio of PNa:PK
2
Q
What happens if K+ permeability increases?
A
Resting potential hyperpolarises - more negative
More K+ ions leave the cell
3
Q
What happens if Na+ permeability increases?
A
Resting potential depolarises - more positive
More ions enter cell
4
Q
What’s the threshold potential in an excitable cell?
A
The potential that must be reached to trigger an action potential
5
Q
Why does changing the extracellular [K+] have greater effect on membrane potential than changing extracellular [Na+]?
A
As membrane more permeable to K+ than Na+
