Definition

Noun 1. The lateral rectus muscle: A specific striated muscle located within the orbit (eye socket). It is one of the six extraocular muscles responsible for moving the eyeball. Its primary and defining action is to abduct the eye, meaning it pulls the eyeball outward, away from the nose, enabling horizontal gaze toward the temple.

Usage Examples

• Noun:
  • The rectus lateralis is innervated by the abducens nerve (cranial nerve VI).
  • Paralysis of the rectus lateralis results in an inability to move the eye laterally, a condition known as abduction deficit.
  • During the examination, the doctor tested the function of the left rectus lateralis.

Advanced Usage

• Clinical Context: The term is used almost exclusively in medical, anatomical, and ophthalmological contexts to describe muscle function, diagnose disorders (like strabismus or nerve palsy), or plan surgical interventions.
• "Lateral rectus" vs. "Rectus lateralis": "Lateral rectus" is the more common clinical term in everyday medical English. "Rectus lateralis" is the formal Latin-derived anatomical name. They are synonyms referring to the same muscle.

Variants and Related Words

• Lateral rectus (muscle) (n): The most common English synonym used in clinical practice.
• Abducens nerve (n): The cranial nerve (VI) that supplies the .
• Abduction (n): The movement of the eye away from the midline, produced by the contraction of the .
• Extraocular muscles (n): The group of six muscles that control eye movements, which includes the .

Synonyms

• Lateral rectus muscle
• External rectus muscle (an older, less common term)

Related Phrases

• Lateral rectus palsy/paralysis: A medical condition where the muscle is weak or paralyzed.
• Lateral rectus recession: A surgical procedure to weaken the muscle's action.
• To test the lateral rectus: A standard part of a cranial nerve examination.

Noun

1. the ocular muscle whose contraction turns the eyeball outward