corticospinal tract

Thân thiện

A student studies a diagram of the corticospinal tract in a neuroscience textbook.

Definition

1. Noun:
   • A major neural pathway: The corticospinal tract is a collection of nerve fibers (axons) that originate primarily in the motor cortex of the brain. It descends through the brainstem and continues down the spinal cord. Its primary function is to carry motor signals from the brain to the spinal cord, enabling voluntary control of body movements, particularly fine, skilled movements of the limbs.

Usage Examples

• Noun:
  • Damage to the corticospinal tract can result in paralysis or weakness on the opposite side of the body.
  • The neurologist explained how signals travel down the corticospinal tract to initiate muscle contraction.
  • In primates, the corticospinal tract is highly developed for precise motor control.

Advanced Usage

• "Lateral corticospinal tract": The major part of the tract that crosses to the opposite side in the medulla and controls movements of the limbs.
  • The lateral corticospinal tract is crucial for the independent movement of fingers.
• "Anterior corticospinal tract": A smaller part of the tract that does not cross immediately and is involved in controlling axial (trunk) muscles.
  • The anterior corticospinal tract primarily influences the muscles of the torso.

Variants and Related Words

• Pyramidal tract: A common synonym for the corticospinal tract, named after the pyramid-shaped structures in the medulla where the fibers pass.
  • The terms "corticospinal tract" and "pyramidal tract" are often used interchangeably.
• Upper motor neuron: A type of neuron whose cell body is in the motor cortex and whose axon forms part of the corticospinal tract.
  • The lesion was located in the upper motor neurons of the corticospinal tract.

Synonyms

• Pyramidal tract: The primary synonym in neuroanatomy.
• Corticospinal pathway: A less common but accurate synonym emphasizing its role as a neural route.

Related Phrases

• Corticospinal system: Refers to the entire functional system involving the corticospinal tract and its connections.
  • The corticospinal system is essential for learned motor skills.
• Descending motor pathway: A broader category that includes the corticospinal tract among other tracts carrying commands from the brain to the spinal cord.
  • The corticospinal tract is the most prominent descending motor pathway for voluntary movement.

Related Idioms

(Note: As a specific anatomical term, "corticospinal tract" is not used in idiomatic expressions. Its usage is strictly technical and scientific.)

Học thuật

Noun

1. any of the important motor nerves on each side of the central nervous system that run from the sensorimotor areas of the cortex through the brainstem to motor neurons of the cranial nerve nuclei and the ventral root of the spinal cord

Từ đồng nghĩa

• pyramidal tract
• pyramidal motor system