AP Contraction Relationship

• AP in the skeletal muscle is very short lived. 
• AP is basically extra component, which extends the duration.
• The contraction is almost over before the action potential has finished.
• Syncronized contraction
• Myocardial cells obey all or none principle
• Electrical activity of the heart
• Action potential of the myocardial cells
• Plato phase 0 phase (upstroke), 1 phase, 2 phase, 3 phase and 4 phase
• Automatic activtty of the heart
• The nodes AV and SA nodes, spontaneous depolarization
• Ectopic focus
• Damage of SA node
• The rate of automatic frequancy of SA node