A threshold potential is A) the same value in every cell B) the peak potential achieved during an action potential. C) the point at which there is an explosive increase in Na⁺ permeability. D) the potential at which K⁺ permeability increases. E) always a positive potential.

Question

Quizplus · Accepted Answer

A threshold potential is the point at which there is an explosive increase in Na+ and K+ ion permeability, leading to the generation of an action potential. This occurs when the depolarization of the membrane reaches a certain level, causing voltage-gated ion channels to open and allowing the influx of Na+ ions and efflux of K+ ions. The threshold potential is not necessarily the same value in every cell and is not the peak potential achieved during an action potential. The potential at which K+ permeability increases is not relevant to the threshold potential, and the threshold potential can be either positive or negative.

A Threshold Potential Is