In this article we will discuss about the monophasic and biphasic types of action potential.
Type # 1. Monophasic Action Potential:
To record a monophasic action potential, one of the recording electrodes should be in ECF and the other in ICF. For biphasic action potential recording, both the recording electrodes can be placed either in ECF or ICF.
The depolarization is because of influx of Na+ and repolarization is because of efflux of K+ (Fig. 2.8) (Flow chart 2.1).
The after depolarization is because of decreased rate of movement of K+ out of cell, as during repolarization phase, the efflux of K+ gradually decreases the concentration gradient for K+ to move out.
Type # 2. Biphasic Action Potential:
i. It can be recorded by placing both the recording electrodes either in the ECF or ICF.
ii. In the Y axis when there is no stimulation of the nerve fiber, there is no potential difference between the two recording electrodes and hence the horizontal line recorded is known as isopotential line.
iii. The recording will have two peaks and one will be the mirror image of the other.
iv. The isopotential duration between the mirror images will depend on the distance between the two recording electrodes and is directly related.
v. The ionic basis of the potential recorded will be same as far monophasic action potential.