The oculomotor nerve innervation, functions of muscles and lesion : magic summary

 

The oculomotor nerve innervation, functions of muscles and lesion

	Innervation	Function	Lesion
Muscle of eyelid	Levator palpebrae superioris	raises the upper eyelid	Ptosis: Drooping of the eyelid due to weakness or paralysis of the muscle responsible for elevating the upper eyelid (levator palpebrae superioris).
Extra-ocular muscle	Superior rectus muscle	eye  rotates upward	Lateral strabismus/squint: due to paralysis of medial rectus and unopposed action of lateral rectus muscle which is supply by abducens  nerve Diplopia on looking medially and superiorly.
	Medial rectus muscle	adducts the eye toward the nose
	Inferior rectus muscle	rotates the eyeball down"
	Inferior oblique	Extortion, elevation, and abduction.
Muscle of pupil	Sphincter papillae	Constriction of pupil (miosis)	Dilated pupil (mydriasis): Loss of pupillary constriction due to paralysis of the sphincter pupillae muscle, which is innervated by the oculomotor nerve.
Muscle alter curvature of lens	Ciliary  muscle	Contraction of this muscle relax suspensory ligament, so diameter of lens increase during near vision (accommodation)	Loss of accommodation: due to paralysis of medial rectus, sphincter papillae and ciliaris muscles.