Question

oke muscle of right lateral rectus:

• A. Lt medial rectus
• B. Lt superior rectus
• C. Lt lateral rectus
• D. Lt inferior oblique

Answer 1

The Correct Option is A

The concept of yoke muscles refers to pairs of muscles that work together to perform eye movements. When one eye moves in a certain direction, its yoke muscle in the opposite eye ensures coordinated movement. The right lateral rectus is a muscle responsible for moving the right eye outward (abduction). To perform a conjugate eye movement (both eyes moving together) to the right, the right lateral rectus works in tandem with the muscle that moves the left eye inward (adduction).

Explanation: The yoke muscle for the right lateral rectus is the muscle that allows the left eye to move in the same horizontal direction as the right eye when both eyes are focusing on an object. The muscles involved are:

• Right lateral rectus: Responsible for moving the right eye outward.
• Left medial rectus: Allows the left eye to move inward, making it turn towards the nose.

The paired action of the right lateral rectus and the left medial rectus allows both eyes to move synchronously for lateral gaze. According to Hering's Law of Equal Innervation, these yoke muscles receive equal neural input to ensure coordinated eye movement. Therefore, in response to the question, the yoke muscle of the right lateral rectus is the left medial rectus.

Correct Answer: Left medial rectus.