Stimulus artifact is a signal that is produced due to an electric pulse present between two electrodes, which is recorded using the cathode ray oscilloscope (Johnson and Byrne, 2003). As the stimulus intensity begins to increase, the stimulus artifact also increases (Johnson and Byrne, 2003). Thus, the change in stimulus artifact allows the compound action potential (CAP) to appear (Johnson and Byrne, 2003). As it can be seen in the figures there’s a delay in time between the stimulus artifact and CAP, this is the reflection time that CAP takes to move from the initial site at the stimulating electrodes to the recording electrodes (Johnson and Byrne, 2003).
CAP, which is a response that had occurred from a graded external action potential …show more content…
This was due to the fact that since the outside of the cell membrane is positively charged and the inside is negatively charged so an increase in permeability of sodium will result in the reversal of the polarity of the cell (Pispati, 2001). Thus, the circuit current flow will occur between the resisting membrane and depolarized region (Pispati, 2001). Due to this the positive charged ions will flow into the depolarized region and evacuate through the resting membrane (Pispati, …show more content…
As shown in figure 6, the absolute refractory period of the sciatic nerve was measured at 1.48 ms. This type of period occurs when the second stimulus of the action potential does not release another action potential due to the strength (Pispati,2001). Therefore, the nerve is nonresponsive to the second stimulus (Pispati,2001). This is due to the ceasing of the sodium channel at the action potential peak (Pispati,2001). The action potential will not occur until the channel opens. (Pispati,2001). Therefore, this is the period where an electrical stimulus will not elicit an action potential due to the fact that the membrane has not been fully repolarized as well as the recovering of the sodium channel has not happened. By comprising absolute refractory period, the total refractory period can be determined, 3.88 ms. This is the refractory where the second CAP has reached its maximum amplitude. Using the two periods the relative refractory can be determined which requires a bigger stimulus. (Sigg et al, 2010). In this period the second CAP released will causes the stimulus strength to be larger than the threshold (Sigg et al, 2010). Therefore, the sodium channels remain inactive, however bigger amount of potassium channels will open (Sigg et al, 2010). Since the membrane potential is near the K+ equilibrium potential and more distant from the
CAP, which is a response that had occurred from a graded external action potential …show more content…
This was due to the fact that since the outside of the cell membrane is positively charged and the inside is negatively charged so an increase in permeability of sodium will result in the reversal of the polarity of the cell (Pispati, 2001). Thus, the circuit current flow will occur between the resisting membrane and depolarized region (Pispati, 2001). Due to this the positive charged ions will flow into the depolarized region and evacuate through the resting membrane (Pispati, …show more content…
As shown in figure 6, the absolute refractory period of the sciatic nerve was measured at 1.48 ms. This type of period occurs when the second stimulus of the action potential does not release another action potential due to the strength (Pispati,2001). Therefore, the nerve is nonresponsive to the second stimulus (Pispati,2001). This is due to the ceasing of the sodium channel at the action potential peak (Pispati,2001). The action potential will not occur until the channel opens. (Pispati,2001). Therefore, this is the period where an electrical stimulus will not elicit an action potential due to the fact that the membrane has not been fully repolarized as well as the recovering of the sodium channel has not happened. By comprising absolute refractory period, the total refractory period can be determined, 3.88 ms. This is the refractory where the second CAP has reached its maximum amplitude. Using the two periods the relative refractory can be determined which requires a bigger stimulus. (Sigg et al, 2010). In this period the second CAP released will causes the stimulus strength to be larger than the threshold (Sigg et al, 2010). Therefore, the sodium channels remain inactive, however bigger amount of potassium channels will open (Sigg et al, 2010). Since the membrane potential is near the K+ equilibrium potential and more distant from the