Ans. A. XIIXII nerve is a motor nerve; does not play role in olfaction and gustation.Cranial Nerves -- Components and FunctionsNumberNameFunctionIOlfactory nerve Smell sensationIIOptic nerve VisionIIIOculomotor Turns eyeball upward, downward,and medially; Raises upper eyelid, alsoconstricts pupil; accommodates eyeIVTrochlear nerve It helps in turning eyeball downwardand laterallyVTrigeminalMaxillarydivisionSupplies dura mater of anterior paof middle cranial fossa, conjunctiva ofinferior eyelid, skin of face over maxilla;teeth of upper jaw; mucous membrane NumberNameFunction OphthalmicdivisionSupplies cornea, superior conjunctiva,skin of dorsum of external nose,forehead, scalp, superior eyelids, andalso mucous nasal cavity, ethmoid,frontal and sphenoid sinuses MandibulardivisionSkin of lower lip, buccal, parotid andtemporal regions of face, external ear(Auricle, tympanic membrane andacoustic meatus), mucous membraneof mouth and anterior two-third paof tongue. Supplies 4 muscles of mastication,mylohyoid, anteriorbelly of digastric, tensor tympani andtensor veli palatini VI Abducent Lateral rectus muscle turns eyeballlaterally NumberName FunctionVIIFacial Taste from anterior two-thirdsof tongue, from floor of mouth andpalate Muscles of face and scalp,stapedius muscle, posterior belly ofdigastric and stylohyoid muscles Submandibular and sublingualsalivary glands,the lacrimal gland, andglands of nose and palate VIII VestibulocochlearCochlear Organ of Coi--hearing VestibularFrom utricle and saccule andsemicircular canals--positionand movement of headIXGlossopharyngeal General sensation and taste fromposterior one-third of tongue andpharynx; carotid sinus (baroreceptor);and carotid body (chemoreceptor) NumberName Function Stylopharyngeus muscle--assistsswallowingParasympathetic parotid salivary gland X Vagus Hea and great thoracic blood vessels;larynx, trachea, bronchi, and lungs;alimentary tract from pharynx tosplenic flexure ofcolon; liver, kidneys, and pancreas XI Spinal accessory Cranial rootSternocleidomastoid and trapeziusmuscles Cranial root Muscles of soft palate (excepttensor veli palatini), pharynx (exceptstylopharyngeal), and larynx (exceptcricothyroid) in branches of vagus XII Hypoglossal Muscles of tongue (exceptpalatoglossus) controlling its shape andmovement