Nerve impulse | generation of nerve impulse | Action membrane potential

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NerveImpulseGeneration

By 

Muhammad Farooq Achakzai 

Write detail note on how nerve impulse generate 

A nerve impulse, also known as an action potential, is generated through a complex series of events that occur within nerve cells, also known as neurons. The following is a detailed explanation of how a nerve impulse is generated:

#Restingpotential: The resting potential of a neuron is its electrical charge when it is not actively transmitting a nerve impulse. The resting potential of a neuron is maintained by the concentration of ions, such as potassium (K+) and sodium (Na+), inside and outside of the cell membrane.

#Depolarization: When a stimulus, such as touch, heat, or chemical signal, is applied to a neuron, it can cause the membrane to depolarize. This means that the electrical charge of the membrane changes and becomes more positive. This change in charge is due to an influx of positively charged sodium ions into the cell and the efflux of positively charged potassium ions out of the cell.

#Thresholdpotential: If the depolarization reaches a critical level, called the threshold potential, it triggers an all-or-nothing response in the neuron. This means that the nerve impulse will either be generated or not, there is no in between.

#Actionpotential: Once the threshold potential is reached, the neuron generates an action potential, or nerve impulse. This occurs through a series of changes in the ion concentration across the cell membrane. Sodium channels in the membrane open, allowing for a rapid influx of sodium ions into the cell, which further depolarizes the membrane. This depolarization in turn triggers other sodium channels to open, causing a wave of depolarization to propagate along the membrane.

#Repolarization: After the wave of depolarization has passed, the sodium channels close and potassium channels open, allowing potassium ions to flow out of the cell. This restores the resting potential and the membrane becomes polarized again.

#Refractoryperiod: After the action potential has been generated, there is a brief period of time, called the refractory period, when the neuron is unable to generate another action potential. This period is necessary to ensure that the nerve impulse is transmitted accurately and that the next nerve impulse can be generated at the proper time.

In summary, a nerve impulse is generated through a series of events that involve changes in the ion concentration across the cell membrane and the opening and closing of ion channels. Once the impulse has been generated, it can be transmitted along the neuron and passed on to other neurons through specialized structures called synapses.

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