Review sheet 3 2 Define the abveMar ngovanwarypriod 3 How di
Solution
2. Absolute refractory period is the peroid immediately after the firing of a nerve fibre when it cannot be stimulated regardless of the intensity of stimulus.
 3. As the interval between the stimuli decreases, the threshold for second action potential increases.
 4. As voltage gated potassium channels are open that oppose depolarisation, greater stimulus is required.
Activity 6
 1. Because after relative refractory period longer stimuli recovery time above threshold allows action potential to occur.
 2. When there is constant source of stimulation action potential occurs more frequently as long as the relative refractory period is reached.
 3. Higher threshold is achieved as compared to the original stimulus intensity as compared to the refractory period.
4. The frequency of action potential is the reciprocal of interspike interval.

