Question

1) What is meant by the term ''resting membrane potential''?

2) What is the usual resting membrane potential of an excitable cell (e.g.neuron) at rest? Why? How is it established?

3) How do the concentration of K+ and Na+ differ in the ECF and the ICF?

Answer 1

1.Resting membrane potential is the difference in the charges across the membrane when cell is at resting.In neuron cells the voltage difference persists like inside the cell will more negative than the outside of the cell. At the resting membrane , sodium ions resides in the cell more than outside ,conversly potassium ion present outside would be higher than the inside.

2.The usual resting potential of an excitable cell like neuron is negative ( -60 to -70 millivolt),it is due to the more sodium extracellularly than the potassium ions intracellularly. It is established via soium -potassium pump which moves two potassium ion inside the cell and three sodium ion moves outside the cell maintains the negative potential through membrane.

3.Sodium ion get concentrated much inextracellular fluid than the intracellular fluid , conversly potassium get concentrated more in intracellular fluid than the extrcellular fluid.It occurs due to the large size anion passes through the plasma membrane results into more negative charge in cytoplasm than extrcellular fluid.