Action potential

Mechanism and function

In an axon, sequential ion-channel opening produces depolarization and repolarization. Signal strength can be encoded by firing frequency and fiber recruitment rather than ever-larger individual impulses.

Assessment and clinical implications

Nerve conduction studies record responses from populations of fibers. They do not directly measure pain experience or detect every small-fiber abnormality.

Points to consider

Neural transmission depends on complementary electrical and chemical properties. A cellular mechanism cannot be measured directly through posture examination. Electrophysiological investigations answer specific questions about nerve or muscle dysfunction.

Role of TAGMED care

At TAGMED, assessment aims to understand symptoms, history and functional limitations. Manual care and osteopathy, motorized spinal decompression, laser and shockwave have different indications. The term described in this entry is not enough to select any of these modalities. Their relevance, limitations and possible contraindications should be discussed in relation to diagnosis and individual goals.

Related concepts and distinctions

These concepts belong to the same field, but are not synonyms.

• Resting membrane potential — Electrical potential difference across an excitable cell membrane when it is not generating an action potential.
• Depolarization — Shift in membrane potential toward a less negative value that may bring an excitable cell closer to action-potential threshold.
• Repolarization — Return of membrane potential toward more negative values after depolarization, forming part of the normal electrical cycle of excitable cells.

Medical references

1. OpenStax, Rice University. Anatomy and Physiology 2e — The Action Potential.
2. OpenStax, Rice University. Anatomy and Physiology 2e — Communication Between Neurons.

References document the topic; their inclusion does not imply endorsement of TAGMED services by those organizations.