Which of the following statements about the response of neurones to stimulus is correct?
A. Neurons respond to stimulus of any strength B. Neurons respond to all stimuli applied in rapid succession C. Neurons respond more rapidly during the absolute refraction period D. Intensity of stimulus must reach a threshold value before the neurons can be excited
Correct Answer: D
Explanation
Each neuron has a threshold that must be met before an action potential travels the length of the neurons axon. In other words, the neurons don't just begin to act immediately, there is a threshold value where the intensity of the stimulus must get to in order to yield a response from the neuron. This is why you can consciously pinch your self and not feel anything serious but when it is unconscious, it gives you serious pain.
