Muscle/MuscleMechanics/SimpleTwitch

POINT!

The initiation of an action potential on the muscle sarcolemma will produce a simple twitch contraction.

A Simple Twitch Contraction

Stimulating the muscle membrane will produce an action potential that last a couple of milliseconds. This will initiate a series of events including the twitch contraction of the muscle. There are three major temporal phases associated with the simple twitch contraction:

1. Latent Period – this is the time between the initiation of the action potential and the beginning of force development by the muscle. During this time the processes involved with excitation-contraction coupling occur as well as the stretching of the series elastic element.

2. Contraction Period – this is the time where the interaction between the thick and thin filaments of the muscle is increasing the force developed.

3. Relaxation Period – this is the time where the force developed by the muscle begins to decrease. During this time the interaction between the thick and thin filaments decreases to zero.

Challenge Quiz

You must wait for the CORRECT! 正確!

<GIFT> //LEVEL:2 //RAND Depolarization of the muscle membrane is required to produce a simple twitch contraction. {=True~False}

//LEVEL:2 //RAND The muscle action potential is much {shorter~longer} than the twitch contraction.

//LEVEL:2 //RAND The first phase of the twitch contraction is the {contraction~=latent~relaxation} period.

//LEVEL:2 //RAND The second phase of the twitch contraction is the {=contraction~latent~relaxation} period.

//LEVEL:2 //RAND The third phase of the twitch contraction is the {contraction~latent~=relaxation} period.

//LEVEL:2 //RAND The contraction period is when force begins to {decrease~=increase~stay the same}.

//LEVEL:2 //RAND The latent period is when force begins to {decrease~increase~=stay the same}.

//LEVEL:2 //RAND The relaxation period is when force begins to {=decrease~increase~stay the same}.