Muscle action potential

Presentation of Muscle action potential from Guyton and Hall physiology chapter 7.

1. MUSCLE ACTION POTENTIAL Presented by AMNA IMRAN

2. Definition The wave of electrical potential which passes across a muscle is known as muscle action potential

3. Quantitative Aspects The procedure is same as that of neuron action potential. Muscle action potential differs in quantitative aspects. In Muscle action potential, •- Resting membrane potential is about -80 to -90 millivolts. •- Action potential occurs for about 1-5 milliseconds. •- Action potential conducts at a velocity of 3-5 meter per second.

4. Excitation contraction coupling The muscle fibers are large and action potential cannot panetrate deep inside each myofibril. Muscle contraction requires current to panetrate deeply into vicinity of each myofibril. It is acquired by TRANSVERSE TUBULES. T tubules release calcium ions inside muscle myofibrils. Calcium ions ultimately causes contraction.