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Anatomy & Physiology vocabulary · Nervous and Endocrine Systems

Action potential

Meaning in anatomy & physiology, with examples

nounAdvanced term

In anatomy & physiology, action potential means: A brief electrical signal that travels along the membrane of a nerve or muscle cell. Sodium ions rush into the cell (depolarization), and then potassium ions flow out (repolarization).

In Turkish: aksiyon potansiyeli, eylem potansiyeli

How it is used

Found in every neurophysiology chapter. An action potential is all-or-nothing: once the threshold is reached it fires fully, otherwise not at all. Related terms are resting membrane potential (about −70 mV in neurons), threshold and refractory period.

Example sentences

  1. An action potential is generated when the membrane reaches threshold.

  2. Myelin allows action potentials to travel much faster along the axon.

Common collocations

  • generate an action potential
  • fire an action potential
  • resting membrane potential
  • threshold
  • refractory period
  • neuronA nerve cell: the basic unit of the nervous system that sends and receives electrical and chemical signals. It has a cell body, dendrites that receive signals and an axon that passes them on.
  • synapseThe junction where a nerve cell passes a signal to another nerve cell, a muscle cell or a gland cell, usually by releasing chemical messengers called neurotransmitters.
  • nerveA cord-like bundle of nerve fibers (axons) that carries electrical signals between the brain or spinal cord and other parts of the body.
  • cell membraneThe thin, flexible layer that surrounds every cell and controls what enters and leaves it. It is made mainly of a double layer of phospholipids with proteins set into it.
  • contractionThe shortening or tightening of a muscle when its fibers are stimulated, producing movement or force. In the heart, contraction pushes blood out of the chambers.

More terms: Nervous and Endocrine Systems

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This page explains English vocabulary for learners. It is not medical advice.