Question

Define: graded potential, action potential, resting potential, all-or-none law, threshold potential, depolarization, repolarization, and hyperpolarization.

A. Graded potential is a brief depolarization, action potential is a continuous change in voltage, and resting potential is the membrane potential during cell inactivity.
B. Graded potential is a local, temporary change in membrane potential, action potential is a brief depolarization, and hyperpolarization is an increase in membrane potential.
C. Graded potential is a local, temporary change in membrane potential, action potential is a continuous change in voltage, and all-or-none law states that not all neurons respond to stimuli.
D. Graded potential is a brief depolarization, action potential is a continuous change in voltage, and threshold potential is the minimum stimulus required to initiate an action potential.

Answer 1

Graded potentials are local membrane potential changes, action potentials are rapid and large changes in membrane potential following the all-or-none law, and the neuron's resting state is known as the resting potential. Depolarization, repolarization, and hyperpolarization are phases of the neuronal action potential process.

Step-by-step explanation:

Definitions of Neural Membrane Potentials and Events

Graded potentials are local, temporary changes in membrane potential that vary in size with the strength of the stimulus. They can either be depolarizing, occurring when positive ions such as Na+ or Ca2+ enter the cell making it less negative, or hyperpolarizing, when positive ions like K+ leave or negative ions like Cl- enter the cell, making it more negative. Action potentials are rapid, substantial depolarizations of the neuronal membrane that occur when a neuron's membrane reaches the threshold potential, the critical level to which it must be depolarized to initiate an action potential. Depolarization during an action potential involves a rapid influx of Na+ ions, reversing the membrane potential from a resting -70mV to around +30mV.

Following depolarization, repolarization occurs as K+ ions exit the cell, restoring the negative charge inside. Hyperpolarization may also follow, where the cell becomes more negative than its resting state. The resting potential is the relatively stable, negative charge of a neuron's membrane when not activated. The all-or-none law dictates that an action potential either occurs fully or not at all when the threshold is reached. After an action potential, the neuron returns to its resting potential and can be activated again, completing an electrical communication cycle.