A 60-year-old man is unable to open his eye because of a rare neuromuscular disease.Which of the following muscles would most likely be paralyzed?
(A) Orbicularis oculi
(B) Orbicularis oris
© Frontalis
(D) Levator palpebrae superioris
(E) Superior rectus
The answer is D. The levator palpebrae superioris muscle opens the eye by elevating the
upper eyelid. The orbicularis oculi closes the eye, the orbicularis oris closes the lips, the
frontalis elevates the eyebrow, and the superior rectus elevates the eyeball.