Question

Topic 2: Resting membrane potential

Describe how a resting membrane potential is established in the wrong. and your answer be sure to include

• A definition of membrane potential

• The resting membrane potential of neurons

• What does this value mean

• What ions are involved in establishing the resting membrane potential? What are the General concentration effects on resting membrane potential? why? The answer should include descriptions of relevant permeabilities, equilibrium potential, and concentration gradients.

• What is the role of the sodium-potassium pump in the resting membrane potential?

Answer 1

Resting membrane potential is established by the uneven distribution of ions across the membrane through different permeability for various ions across membrane. The resultant electric potential due to distribution of charged particles between the interior and the exterior of membrane is the membrane potential. The resting membrane potential is around -70 mV which indicates that the outside of the cell is 70mV more than the inside.

In a resting cell, there is higher sodium concentration extracellualrly and higher potassium concentration intracellularly. The difference in permeability for potassium, sodium, calcium, and chloride resulting in resting membrane potential RMP. Voltage is established when the cell membrane is polarized due to difference in potentials between intra and extracellular spaces. Resting cell favours the permeability for K+ ions and the the resting membrane potential is -70mV is much closer to the equilibrium potential of K+ (-90 mV).

Equilibrium potential is the membrane potential when the net flow ceases through any open channels.

Sodium potassium pump is necessary to maintain the resting potential which pumps two potassium ions inside the cell as three sodium ions are pumped out to maintain the negatively-charged membrane inside the cell.