Definition

Noun 1. The ocular muscle whose contraction turns the eyeball medially: The rectus medialis is one of the six extraocular muscles that control the movement of the eye. Specifically, its primary function is to adduct the eye, meaning it pulls the eyeball inward, toward the nose.

Usage Notes

• The term is a specific anatomical term. In more common anatomical language, it is often referred to simply as the medial rectus muscle.
• It is used almost exclusively in medical, anatomical, and optometric contexts.
• It is typically paired with its antagonist muscle, the (lateral rectus), which pulls the eye outward.

Examples

• Noun:
  • The ophthalmologist tested the function of the rectus medialis by asking the patient to look toward their nose.
  • A palsy of the rectus medialis can result in an outward deviation of the eye, a condition known as exotropia.
  • During the surgery, the surgeon carefully isolated and adjusted the tension on the rectus medialis.

Advanced Usage

• "Rectus medialis palsy": A condition where the muscle is weak or paralyzed, leading to impaired ability to move the eye inward.
  • The patient's double vision was diagnosed as being caused by a rectus medialis palsy.

Variants and Related Words

• Medial rectus (muscle): The most common synonym in general anatomical and clinical use.
• Extraocular muscles: The group of six muscles (including the rectus medialis) that control eye movements.
• Rectus lateralis: The opposing muscle that abducts the eye (turns it outward).

Synonyms

• Medial rectus muscle
• Internal rectus muscle (less common)

Related Anatomical Terms

• Adduction: The movement of turning the eye inward, toward the midline of the body, which is the action performed by the rectus medialis.
• Oculomotor nerve (Cranial Nerve III): The nerve that provides motor control to the rectus medialis, as well as several other extraocular muscles.

Noun

1. the ocular muscle whose contraction turns the eyeball medially