This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anatomy, Subject name: Ophthalmology
[{'content': 'Upper Lid Retractors include ? \nSelect and explain. \nA. Muller muscle and superior rectus, B. Levator palpabrae superioris and superior oblique, C. Superior oblique and superior rectus, D. Levator palpabrae superioris & muller muscle', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Levator palpabrae superioris & muller muscleo The levator palpebrae superioris is the important upper eye lid retractor. Injury or weakness to this muscle leads to ptosis.o This muscle is supplied by occulomotor (3rd) nerve.o Deep part of the elevator muscle is the Muller's muscle, which is sympathetically innvervated.o In hyperthyroidism, sensitization of the Muller muscle leads to upper eyelid retraction and pseudoproptosis,o On the other hand, in Horner's syndrome loss of this muscle action leads to ptosis.o The capsulopalpebral fascia assists in lower eyelid retraction and coordinates with eyeball movement. It arises as an extension of the inferior rectus and inserts into the lower edge of the lower tarsus and the adjacent orbital septum.", 'role': 'assistant'}]