Question

a) What role does positive feedback play in the generation of the action potential? b) The concentration of which ion would you change extracellularly to increase the probability of generating an action potential and why? State clearly whether you would increase or decrease the concentration.

Answer 1

A) when a membrane potential increases, sodium ions from exterior of the cell enters inside the cell since sodium channels are open. Increase in sodium positive ions results in opening of more sodium channels and thereby firing action potential

B) to increase the membrane potential sodium influx channels opened up and Na+ ions enters inside from extracellular thus results in decrease in sodium ions outside and pottassium efflux channel opens up which release potassium ions outside or extracellular which results in increase in concentration of possium ions extracellular which results in furthermore increase of membrane action potential