depolarization

/'di:,poulərai'zeiʃn/

Thân thiện

A neuron undergoes depolarization when a signal arrives.

Definition

1. Noun:
   • A loss of polarity or polarization: The process or act of reducing or eliminating polarity, especially the difference in electric charge across a membrane or between two points. In a broader physical sense, it refers to the removal of a state of polarization, where opposite ends or sides have contrasting properties.

Usage

• This term is primarily used in scientific contexts, specifically in physics and biology.
• In biology/physiology, it most commonly describes the change in a cell's membrane potential, making it less negative (or more positive) compared to the surrounding environment, which is a critical step in the firing of nerve cells (neurons) and muscle cells.
• In physics, it describes the reduction or removal of polarization in waves (like light) or in electric fields.

Examples

• In a biological context:
  • The rapid depolarization of the neuron's membrane triggers an action potential.
  • Cardiac muscle contraction is initiated by the depolarization of the sinoatrial node.
• In a physical context:
  • The filter caused the depolarization of the polarized light beam.
  • The process of depolarization in the dielectric material reduced its stored charge.

Advanced Usage

• "Membrane depolarization": A specific term in physiology for the change in membrane potential toward zero or a positive value.
  • Sodium ion influx is responsible for the initial phase of membrane depolarization.
• "Dielectric depolarization": In physics, the reduction of polarization within an insulating material.
  • The study focused on the kinetics of dielectric depolarization.

Variants and Related Words

• Depolarize (verb): To undergo or cause depolarization.
  • The stimulus will depolarize the cell membrane.
• Depolarizer (noun): A substance or agent that causes depolarization.
• Repolarization (noun): The process of restoring the membrane potential to its resting state after depolarization.
• Hyperpolarization (noun): The process of making the membrane potential more negative than the resting potential.

Synonyms

• Loss of polarity
• Discharge (in specific electrical contexts)
• Neutralization (in a general sense of removing opposite charges)

Antonyms

• Polarization
• Hyperpolarization (in a biological context)
• Polarity

Related Phrases / Compound Terms

• Action potential depolarization phase: The specific part of the nerve impulse cycle where depolarization occurs.
• Depolarization block: A condition where sustained depolarization of a membrane prevents further normal electrical activity.

Học thuật

Noun

1. a loss of polarity or polarization

Từ đồng nghĩa

• depolarisation