depolarisation

Thân thiện

A neuron undergoes depolarisation when a signal travels along its axon.

Definition

Noun: 1. A loss of polarity or polarization: The process or act of removing or reducing polarity, especially the reduction or elimination of the difference in electric potential across a membrane, such as in a nerve or muscle cell.

Usage

Depolarisation is a technical term primarily used in scientific contexts, especially in biology, physics, and chemistry. It describes the state change where a polarized condition is diminished or removed. - In biology, it most commonly refers to the change in a cell's membrane potential, making it less negative (more positive) compared to the outside, which is a critical step in the conduction of nerve impulses or muscle contraction. - In physics and materials science, it can refer to the reduction of polarization in a dielectric material or light wave.

Examples

• In Physiology:
  • The rapid depolarisation of the neuron's membrane triggers an action potential.
  • Cardiac muscle contraction is initiated by the depolarisation of the sinoatrial node.
• In Physics/Chemistry:
  • The experiment measured the depolarisation of light passing through the scattering medium.
  • Applying an external field can cause the depolarisation of the ferroelectric material.

Advanced Usage

• "Membrane depolarisation": A specific term in physiology for the reduction of the electrical charge difference across a cell membrane.
  • Voltage-gated sodium channels open in response to initial membrane depolarisation.
• "Depolarisation block": A state where sustained depolarisation of a membrane prevents the generation of new action potentials.
  • The drug causes a depolarisation block at the neuromuscular junction.

Variants and Related Words

• Depolarize (verb): To undergo or cause depolarisation.
  • The stimulus will depolarize the cell membrane.
• Depolarizer (noun): An agent or device that causes depolarisation.
• Repolarisation (noun): The process of restoring the membrane potential to its resting state after depolarisation. (This is an antonym in a biological sequence).

Synonyms

• Reduction of polarity
• Discharging (in specific electrical contexts)
• Loss of polarization

Antonyms

• Polarisation (UK) / Polarization (US)
• Hyperpolarisation (making the membrane potential more negative than the resting potential)

Học thuật

Noun

1. a loss of polarity or polarization

Từ đồng nghĩa

• depolarization