<prompt> Mullers muscle is supplied by:3rd cranial nerve4th cranial nerveSympathetic fibersParasympathetic fibers  <response>: Each eyelid from anterior to posterior consists of thefollowing layers:1. Skin2. Subcutaneous areolar tissue3. Layer of striated muscle orbicularis oculi andlevator palpebrae superioris in upper lid only4. Submuscular areolar tissue5. Fibrous layer tarsal plate and septum orbitale6. Layer of non-striated muscle fibres Mullersmuscle7. Conjunctiva Layer of striated muscle. consists of orbicularis muscle which forms an oval sheet across the eyelids. It closes the eyelids and is supplied by zygomatic branch of the facial nerve. in paralysis of facial nerve there occurs lagophthalmos which may be complicated by exposure keratitis. Levator palpebrae superioris muscle LPS.main muscle It arises from the apex of the orbit and is inseed by three pas on the skin of lid, anterior surface of the tarsal plateand conjunctiva of superior fornix. It raises the upper lid. It is supplied by a branch of oculomotor nerve Layer of non-striated muscle fibres. It consists of the palpebral muscle of Muller ascessory musclewhich lies deep to the septum orbitale in both the lids. In the upper lid it arises from the fibres of LPS muscle in the lower lid from prolongation of the inferior rectus muscle and is inseed on the peripheral margins of the tarsal plate. It is supplied by sympathetic fibres it helps in initial 15o opening of eye . 