Why is it that after continuous simulation for extended periods of time, it becomes difficult to conduct nerve impulse along a fibre?
2006-12-18 14:54:53 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Biology
I am not a Doctor, but I'm going to take a stab at this one.
Impulses are moved along the nerve and across the gaps between nerves on their way to the brain by an electro-chemical reaction. Repeated firing of the nerve uses up the chemicals needed (potassium and sodium I think) to make the reaction. When the level of sodium/potassium drops the nerve cannot send any further impulses until the chemicals have been replaced.
I think that is what is happening....
2006-12-18 15:03:27 · answer #1 · answered by krinkn 5 · 1⤊ 1⤋
Conduction of nerve impulse along an axon is an electro-chemical phenomenon. When no nerve impulse is passing, the nerve is said to be in resting stage. At this stage the axon periphery is positively charged because of the presence of sodium ions. The moment the impulse is conducted,the voltage-gated sodium channel opens allowing the sodium ion to get inside the membrane.This happens in sequence as the impulse travels along the axon.This is called depolarization.After the nerve impulse has traveled up to the axon bulb, the axon has to restore to it original state, in which the sodium ions have to move up the channel and lie outside the axonal membrane.And this take a microsecond.This small period is called refractory period, during which the nerve impulse will not pass.
When there is continuous stimulation this restoration, which is energy dependent and a biochemical process, is not given enough time, because of which the conduction of impulse is halted.
2006-12-18 16:14:17 · answer #2 · answered by Ishan26 7 · 0⤊ 0⤋
Because the muscle fiber has to have two main things to contract, oxygen and ATP (the nerve impulse is a given). You will never run out of ATP so the most likly answer for that would be it's not getting enough oxygen to the fiber which makes the fiber produce lactic acid. The muscle fiber will respond slower because of this fact even though it's getting that same impluse as it did at the beginning.
2006-12-18 19:27:50 · answer #3 · answered by Billy M 1 · 0⤊ 0⤋
Nerve Impulse? Whatever in the whole wide world is that?
2006-12-18 20:36:07 · answer #4 · answered by Nandita Y 2 · 0⤊ 0⤋
krinkin had the right answer, the neurotransmitters in the synaptic bulb need to be replaced after each signal, and after repeated signals, the reuptake pumps and transport proteins can't keep up with demand
2006-12-18 16:46:20 · answer #5 · answered by jennypjd 3 · 0⤊ 0⤋