Question

Write a paraphaph explaining the differences and similarities between the SA node action potential and cardiac muscle action potential graph.

Answer 1

The cardiac action potential is a brief change in voltage across the cell membrane of heart cells. This causes the movement of charged atoms between the inside and outside of cell through proteins called ion channels .The cardiac action potential differs from action potential found in other types of electrically excitable cells such as nerver. Action potential also vary within the heart this is due to the presence of different ion channels in different cells.

SA NODE ACTION POTENTIAL :are divided into 3 phases. Phase 4 is the spontaneous depolarization that triggers the action potential once the membrane potential reaches threshold between -40 and -30 mV. Phase 0is the depolarization phase of the action potential. This is followed by phase 3 repolarization. Once the cell is completely repolarized at about -60 mV the cycle is spontaneously reapeated