CMD 377 Lecture Notes - Lecture 6: Levator Palpebrae Superioris Muscle, Pupillary Light Reflex, Lateral Rectus Muscle
Document Summary
Motor nucleus for cn iii located in the midbrain oculomotor nucleus. Supplies the visceral motor component of the following muscles: pupillary sphincter controls the size of the pupil, ciliary muscles changes the shape of the lens (accommodation) Lesions: central lesion both nuclei are damaged, lesion to cn iii ipsilateral signs. Inability to move affected eye medially or laterally. Abnormal pupillary light reflex: absence of pupillary constriction in affected eye. Inability for affected eye to focus on near objects. Supplies the superior oblique muscles: concerned with the downward movement of the eye (when in medial position) Cell bodies located in the contralateral trochlear nucleus. Cn iv is the only cranial nerve that is: attached to the dorsal surface of the brainstem, completely crossed (originating from a contralateral nucleus) Lesions: damage to the nerve results in less significant deficit, diplopia when attempting to move eyes downward. Difficultly in descending stairs and reading: lesion contralateral sign.
