Chapter 13: Central Nervous System and Cranial Nerves

Cranial nerve I type?

Sensory nerve / Olfactory nerve

Cranial nerve I name and function?

Olfactory nerve → smell

Clinical condition associated with CN I damage?

Anosmia (loss of smell)

Cranial nerve II type?

Sensory nerve

Cranial nerve II name and function?

Optic nerve → vision

Clinical condition associated with CN II damage?

Anopia (blindness)

Cranial nerve III type?

Motor nerve

Cranial nerve III name?

Oculomotor nerve

CN III function (eye coordination)?

Involved in getting both eyes to focus on one object

CN III function (eyelid + pupil)?

Raises eyelids and adjusts amount of light entering eyes (through pupils)

Clinical conditions from CN III damage?

Diplopia (double vision), ptosis (drooping eyelids), strabismus (eyes cannot focus on one object)

Cranial nerve IV type?

Motor nerve

Cranial nerve IV name?

Trochlear nerve

CN IV function?

Downward and lateral movement of eyeball (superior oblique muscle)

Clinical conditions from CN IV damage?

Diplopia, ptosis, strabismus

Cranial nerve V type?

Both sensory and motor nerve

Cranial nerve V name?

Trigeminal nerve

CN V sensory function?

Touch, pain, temperature of face and mouth

CN V motor function?

Facial expressions and chewing

Clinical condition from CN V damage?

Paralysis of chewing muscles (dental anesthesia)

Cranial nerve VI type?

Motor nerve

Cranial nerve VI name?

Abducens nerve

CN VI function?

Movement of eyeball away from midline laterally (abduction)

Clinical condition from CN VI damage?

Cannot move eyes laterally

Cranial nerve VII type?

Both sensory and motor nerve

Cranial nerve VII name?

Facial nerve

CN VII motor/sensory functions?

Facial expression and taste sense

What part of tongue does CN VII supply taste to?

Anterior ⅔ of the tongue

Clinical conditions from CN VII damage?

Bell’s Palsy (facial drooping on one side), loss of taste

Cranial nerve VIII type?

Sensory nerve

Cranial nerve VIII name?

Vestibulocochlear nerve

CN VIII function?

Balance and hearing

Clinical conditions from CN VIII damage?

Vertigo (dizziness), tinnitus (ringing in ears)

Cranial nerve IX type?

Both sensory and motor nerve

Cranial nerve IX name?

Glossopharyngeal nerve

CN IX sensory and motor functions?

Taste and elevates pharynx when swallowing

What part of tongue does CN IX supply taste to?

Posterior ⅓ of the tongue

Clinical conditions from CN IX damage?

Difficulty swallowing, loss of taste, no feeling in throat

Cranial nerve X type?

Both sensory and motor nerve

Cranial nerve X name?

Vagus nerve

CN X major anatomical function?

Supplies most organs in thoracic and abdominal cavities

CN X physiological functions?

Taste, monitors blood pressure and heart rate, swallowing, GI tract movement (peristalsis)

Clinical conditions from CN X damage?

Vasovagal nerve response, paralyzed vocal cords

Cranial nerve XI type?

Motor nerve

Cranial nerve XI name?

Accessory nerve

CN XI function?

Movement of head and shoulders, swallowing

Clinical condition from CN XI damage?

Paralyzed sternocleidomastoid (SCM) muscle

Cranial nerve XII type?

Motor nerve

Cranial nerve XII name?

Hypoglossal nerve

CN XII function?

Movement of tongue, swallowing

Clinical conditions from CN XII damage?

Difficulty chewing, speaking, or swallowing