ACTION CURRENT Meaning and
Definition
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Action current refers to the flow of electrical charges along the axons of neurons, specifically during the transmission of nerve impulses. It is also known as an action potential or a spike potential.
When a neuron receives a stimulus, such as a sensory input or a signal from another neuron, it generates an electrical current. This electrical current is called an action current. It involves a rapid change in the electrical potential across the membrane of the neuron, causing an electrochemical signal to be propagated along the axon. The action current is an all-or-nothing event, meaning that it occurs only when the threshold level of excitation is reached.
The generation of an action current involves a complex interplay of ion channels in the neuronal membrane. At rest, the neuron has a negative electrical charge inside and a positive charge outside. When stimulated, the neuron's ion channels open, allowing positive ions, such as sodium (Na+) and potassium (K+), to flow into or out of the cell. This results in a rapid depolarization of the membrane, causing the potential difference to become positive. Subsequently, repolarization occurs as the ions are returned to their original states, restoring the negative charge inside the neuron.
The action current moves along the axon at a high speed, facilitated by the myelin sheath, a fatty substance that insulates the axon. This helps prevent the loss of electrical charge and speeds up the transmission process. Action currents play a pivotal role in enabling communication between neurons, allowing the transmission of signals and coordination of various bodily functions.
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An electrical current induced in a contracting muscle.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
Common Misspellings for ACTION CURRENT
- zction current
- sction current
- wction current
- qction current
- axtion current
- avtion current
- aftion current
- adtion current
- acrion current
- acfion current
- acgion current
- acyion current
- ac6ion current
- ac5ion current
- actuon current
- actjon current
- actkon current
- actoon current
- act9on current
- act8on current
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