skeletal muscle contraction

[nuterke]

How does a skeletal muscle fibre contract, without stimulation (voltage)? i was asked to work out an experiment and have no clue.

 

thanks!

[Ringer]

Is this homework? I'm going to answer as if it is. Think about what happens when the threshold for contraction is reached. What ions are released and what do they react with. How could you replicate those steps without an action potential?

[nuterke]

this was a theory i was thinking about:

Due to the action potential calcium enters the neuron, causing vesicles containing acetylcholine to fuse with the membrane with exocytosis as a result. ACH then binds to its receptors on the motor end plate, causing another potential.
So maybe we can add neurotransmitter to the muscle cell?

 

It is indeed homework, answering it right grants 1 bonus point for our practicum grades.

(and i'm dutch so sorry for my slobbish english)

[Ringer]

Don't worry about the neuron unnecessarily. Muscle cells can contract without neuronal stimulation (such as cardiac muscles) so neurotransmitters aren't necessary. Think of what fibers cause the actual contraction and the molecules involved. Skeletal muscles release a specific ion that may be artificially introduced, or its release artificially induced without an action potential.