what is overshoot in anatomy
This is called action potential. Action potential is the change in electrical potential that occurs between the inside and outside of a nerve or muscle fiber when it is stimulated, serving to transmit nerve signals.
Single action potentials follow the "all or none" rule. That is, if a stimulus is strong enough to depolarize the membrane of the neuron to threshold (~55mV), then an action potential will be fired. Each stimulus that reaches threshold will produce an action potential that is equal in magnitude to every other action potential for the neuron. Compound action potentials do not exhibit this property since they are a bundle of neurons and have different magnitudes of AP's. Thus compound action potentials are graded. That is, the greater the stimulus, the greater the action potential.
Action potential duration in skeletal muscle is around 2 - 5 milliseconds.
The generation of a second action in some neurons can only happen after a refractory period, when the membrane potential has returned it's base level or even more negative. This is because some types of Na+ channels inactivate at a positive potential and then require a negative potential to reset. Other neurons have other types of channels and can fire multiple action potentials to a single depolarization.
neuron
After a neuron fires, there is a refractory period where certain factors in the neuron prevent it from being depolarized again. This is made possible by an "overshoot" of polarization (returning to a much stronger negative ion charge inside the neuron) after the action potential passes. This ensures that voltage-controlled ion channels remain closed for a small period of time and do not become overactive through continuous restimulation.
Hyperpolarization occurs because some of the K+ channels remain open to allow the Na+ channels to reset. This excessive amount of K+ causes hyperpolarization so the Na+ channels open to bring the potential back up to threshold.
It creates an action potential
This is called action potential. Action potential is the change in electrical potential that occurs between the inside and outside of a nerve or muscle fiber when it is stimulated, serving to transmit nerve signals.
When a stimulus stimulates a neuron above the threshold, the action potential is generated.
Curare does NOT create an action potential. It binds to nicotinic acetylcholine receptors (which are primarily excitatory), and prevents the formation of an action potential.
It doesn't. I prevents an action potential from forming.
Action potential
action potential
Single action potentials follow the "all or none" rule. That is, if a stimulus is strong enough to depolarize the membrane of the neuron to threshold (~55mV), then an action potential will be fired. Each stimulus that reaches threshold will produce an action potential that is equal in magnitude to every other action potential for the neuron. Compound action potentials do not exhibit this property since they are a bundle of neurons and have different magnitudes of AP's. Thus compound action potentials are graded. That is, the greater the stimulus, the greater the action potential.
The areas that have had the action potential are refractory to a new action potential.
Why does artifact always appear ahead of action potential?