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Order of events prior to nerve impulse conduction

1)Threshold stimulus is received.
2) Sodium channels in a local region of the membrane open.
3) Sodium ions diffuse inward, causing the membrane to depolarize.
4) Potassium channels in the membrane open at about the same time.
5) Potassium ions diffuse outward, causing the membrane to repolarize (back to initial charge).
6) Some Potassium channels remain open causing hyperpolarizing.
7) Wave of action potentials travels the length of the nerve fiber as a nerve impulse.

Thank you

Nerve impulses travel due to shifting in the balance of Sodium(Na) and Potassium(K) ions interior and exterior to the nerve. Thus, Na and K is essential for conduction of neural signals, including those signals which order the muscles to contract. Electrochemical gradients and changes in them result in activation of enzymes that are involved in muscle contraction. The general process in which muscles contract goes as follows. Nerves release acetylcholine which binds to acetylcholine receptors which cause an influx of sodium ions which depolarizes the cell membrane causing calcium to be released which phosphorylates various enzymes that phosphorylate myosin heads enabling them to contract. To repolarise the membrane, after a certain amount of time, potassium channels open up allowing potassium to flow out repolarising the membrane. Ionic homeostasis is then re-obtained by pumps which pump sodium out and potassium in.