resting action potentials

Question 1

a. Explain the ionic permeability of the resting cell membrane and the factors influencing ionic distribution across the cell membrane

Answer 1

In neurons and their surrounding fluid, the most abundant ions are:

High conc inside : k+ (150 mM)
Low conc : Cl- (5 mM) and Na + (15 mM)

Cell membranes at rest: ​
Fairly readily permeable to K+ and Cl-​
Poorly permeable to Na+​
Impermeable to various large organic anions

Two fundamental properties of cells give rise the resting membrane potential:
Selective permeability of the cell membrane (PK&raquo_space; PNa) ​
Unequal distribution of ions across membrane (maintained by Na+/K+ pump)

Question 2

b. Explain how voltage-controlled ion channels regulate membrane conductance

Question 3

describe the current and voltage changes during the action potential in excitable cells