Action potential
Definition
An action potential is a rapid, temporary change in the electrical membrane potential of a neuron. It allows for the transmission of nerve impulses along the neuron and to other cells.
5 Must Know Facts For Your Next Test
- Action potentials are initiated when a neuron reaches its threshold potential.
- The process involves depolarization, where sodium ions rush into the cell, followed by repolarization.
- The refractory period ensures that action potentials only travel in one direction along an axon.
- Myelinated neurons conduct action potentials faster due to saltatory conduction.
- Action potentials are all-or-nothing events; they either happen completely or not at all.
Review Questions
- What triggers the initiation of an action potential?
- Explain the role of sodium and potassium ions during an action potential.
- Why is the refractory period important in neural communication?
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Related terms
Depolarization: A phase during an action potential when the inside of a neuron becomes less negative due to influx of sodium ions.
Refractory Period: A brief time after an action potential during which a neuron is unable to fire another action potential.
Saltatory Conduction: The process by which action potentials jump from one node of Ranvier to the next in myelinated neurons, speeding up signal transmission.
