Origin of Bio-electric Signal: Action-potential across the cell is responsible for all bio-electric signals because the bio-electric signal from anybody organ are combined effect of bio-potential across the cell in that organ.
There are two main elements which are responsible for potential generation semi permeable membrane and ions (Na+\ K\ Cl") present in the surrounding of cell.
In complete potential generation process the cell boundary (membrane) characteristic play important role, because it has following properties:
11) If cell is resting the membrane allows the entrance of K/ion more than other.
(ii! If any external stimulus is applied at cell than
Rate of Na+ > Rate of K+ outside
Three main subprocess takes place in potential generation across cell:
(1) CeI1 polarization (ii) Cell depolarization
(iii) Cell repolarization
When cell at rest Kr move inside and chemical imbalance occur and due to th. t cell polarized. Now if external stimulus applied it maintains the charge inside and charge outside this called cell polarization.
Now, when stimulus is removed after sometime cell becomes at rest and repolarization takes place. In generation of action potential cell follows "all or nothing law."
According to that "Peak value of action potential does not depends upon strength of stimulus."