Action potential and strength of muscle contraction?

[scilearner]

Hello guys,

 

Although the response of a motor unit is all-or-none, the strength of the response of the entire muscle is determined by the number of motor units activated. Nerve impulses passing down a single motor neuron will thus trigger contraction in all the muscle fibers at which the branches of that neuron terminate. and this is a motor unit.

 

1.My question is some organs are supplied only with one motor neuron, is it impossible for them to control the strength of their contraction?

2.Also this is just about the central nervous system. Since CVS has many nerves which are branches of other nerves, when an action potential is sent how come this action potential doesn't travel through the branches and innervate unnessecary structures?

 

Thanks for anyone who is going to help

[insane_alien]

question 1/ have you googled?

 

question 2/ have you googled?

[NADH]

I think you second question has to do more with the function of the thalamus than anything else. The thalamus directs the impulse signals. So they only go to their appropriate locations. I don't see why the impulse would disrupt other organs. Its like saying why do we run when their if fire? Its because our brain tells us.