MUSCLE PHYSIOLOGY

Detailed explanation-1: -Definition: Sub-threshold (or subthreshold) refers to a stimulus that is too small in magnitude to produce an action potential in excitable cells . In general, a sub-threshold stimulus leads to the depolarization of the membrane, but the magnitude of the depolarization is not large enough to reach the threshold voltage.

Detailed explanation-2: -The minimum stimulus needed to achieve an action potential is called the threshold stimulus. The threshold stimulus causes the membrane potential to become less negative (because a stimulus, no matter how small, causes a few sodium channels to open and allows some positively-charged sodium ions to diffuse in).

Detailed explanation-3: -Answer and Explanation: A subthreshold stimulus is a stimulus that will cause a slight depolarization of a neuron’s membrane, but will not depolarize it to its threshold potential of-55 mV.