Question

movement of the extraocular muscles: is mediated by cranial nerves iii (oculomotor), iv (trochlear) and vi (abducens) is impaired in a patient with cataracts requires binocular vision is decreased in the elderly question 6 (mandatory) (2 points) listen skin sensation to the face is primarily via cranial nerve v cranial nerve vii cranial nerve vi cranial nerve viii

Explanation:

• For the first question:
• The oculomotor nerve (III) innervates most extraocular muscles, the trochlear nerve (IV) innervates the superior oblique muscle, and the abducens nerve (VI) innervates the lateral rectus muscle. So, the movement of extraocular muscles is mediated by cranial nerves III, IV, and VI.
• Cataracts affect the lens and vision, not extraocular muscle movement. Binocular vision is about depth perception, not the cause of extraocular muscle movement. There is no general decrease in extraocular muscle movement in the elderly as a primary characteristic.
• For the second question:
• Cranial nerve V (trigeminal nerve) has three branches (ophthalmic, maxillary, mandibular) that are mainly responsible for facial skin sensation.
• Cranial nerve VII (facial nerve) is mainly for facial muscle movement (except the muscles of mastication). Cranial nerve VI (abducens nerve) is for lateral rectus muscle movement (eye movement). Cranial nerve VIII (vestibulocochlear nerve) is for hearing and balance.

Answer:

• First question: is mediated by cranial nerves III (oculomotor), IV (trochlear) and VI (abducens)
• Second question: Cranial nerve V