What are the phases of the action potential?

Usually, the phases of the action potential are summarized in five steps, the first of which are growing and exceeding phases. The last three steps would be a fall, underground and recovery phases. Some sources, whether physiologists or textbooks, sometimes include the initial resting phase before the growing phase in the list of action potential phases, they probably illustrate the quo neuron status before the start of action. In the simplest sense, the action potential can be described as short electrical pulses that are formed inside the neuron cell body. These pulses are caused by the exchange of positive and negative ions when the potassium and sodium ions retreat and enter the cellular body. The "spark" from the stock exchange then travels to the axon or stemly part of the neuron, towards another neuron and the cycle continues. In many cases where the brain needs to "send" many "messages", action potential may occur in a row called "Spike Train".

Neuron usually contains positively charged potassium ions (+K), while sodium ions (+NA), also positively charged, are based on the periphery of neurons. During the resting phase, the neuron is inactive and contains "electrical potential" -7 Milivolt (MV). This negative charge is maintained by a neural sodium-pawn pump that brings two +K ions, while transmitting three +to the membrane ions. When the brain "sends" a message, a large number of ions +Na enters the neuron and increases and exceeds action potential. At these stages of neuron, it is experiencing "depolarization" and is positively charged due to +on ions.

Neuron reaches the phase of exceeding when its positive charge exceeds 0 mv. The more positively the neuron becomes, the more sodium channels begin to open and the ions +NA plunges more, making it difficult for the potassium sodium to bring the ions. In order to release positive ions, open potassium channels open as soon as sodium channels close and falling and underdivot phase of action potential occursu. At these stages of neuron, it experiences "repolarization" and becomes a more negative charged, so much that the charge will be hit under -70 mV in the stages, also known as "hyperpolarization".

After closing both potassium and sodium channels, sodium sodium pump works more efficiently when bringing +K ions and performing +on ions. In this final recovery phase, the neuron returns to its normal -7 mV until the next episode of the action potential occurs. It is very interesting to know that all these phases of the action potential occur in the AS Great as two milliseconds.