15. The threshold potential is of great significance in the physiology of neurons because if the threshold potential is not reached, __________.
A.the neuron cannot regain its resting potential
B.the action potential will be "inversed," with a flux of sodium out of the cell rather than into it
C.an action potential will not occur
D.an action potential will be reached
E.None of these choices relate to threshold depolarization.
C, the threshold must be reached for the neuron to "fire."
I hope this helps. Thanks for asking.
The correct answer is C. an action potential will not occur.
The threshold potential is the membrane potential that a neuron must reach in order to generate an action potential. It is usually around -55mV to -50mV in most neurons. When the membrane potential reaches or surpasses this threshold, it triggers an action potential, which is a rapid and brief electrical impulse that allows neurons to communicate with each other.
If the threshold potential is not reached, an action potential will not occur. This is because the threshold is the minimum level of depolarization required to open voltage-gated sodium channels in the neuron's membrane. These channels allow a influx of sodium ions into the neuron, leading to depolarization and the propagation of the action potential along the neuron.
If the threshold is not reached, the voltage-gated sodium channels will not open, and the neuron will not generate an action potential. The neuron will remain in its resting state and will not transmit any electrical impulses. This highlights the significance of the threshold potential in the physiology of neurons as it is a crucial step in initiating the electrical signaling process.