Question

1.) Mixed cranial nerves containing both motor and sensory fibers include all of the following except the ____.

A. trigeminal

B. facial

C. vagus

D. optic

Answer 1

• The optic nerve is the sensory nerve. It is not a mixed nerve. It is the second cranial nerve .It is the nerve of sight . The correct answer is optic nerve.
• Trigeminal nerve is the fifth cranial nerve which is mixed nerve. It has three divisions ophthalmic , maxillary and mandibular division.
• The ophthalmic division is pure sensory division. The branches of this nerve is frontal, nasociliary and lacrimal.
• The maxillary nerve provides sensory innervation to the midface region.It provides sensation to the palate , maxillary teeth & paranasal sinuses.
• The mandibular division innervates the mandibular teeth and muscles of mastication .Also innervates the anterior belly of the digastric muscle, mylohyoid muscle, tensor tympani and tensor veli palatini.
• Facial nerve is the seventh cranial nerve. It is the mixed nerve .It provides motor innervation to the muscles of facial expressions and sensation of taste to the anterior 2/3rd of tongue ,hard and soft palate.
• The vagus nerve is tenth cranial nerve.It innervates the muscles of larynx and pharynx .It supplies the viscera of the neck ,thorax and abdomen.
• It provides taste sensation from the posterior 1/3rd region of tongue.
• Hence, all the three nerves are mixed only optic nerve is sensory nerve.