A&P 9 nervous system 2

Question 1

CN I

Answer 1

Olfactory nerve- carries info from the nose to the brain. concerned with the sense of smell. Damage results in loss of smell or anosmia.

Question 2

CN II

Answer 2

Optic Nerve- Sensory nerve that carries visual info from the eye to the occipital lobe of the cerebrum. Damage causes diminished vision or blindness in the affected eye.

Question 3

CN III

Answer 3

Oculomotor nerve- A motor nerve that causes contraction of the extrinsic eye muscles, thereby moving the eye ball in its socket. ALso raises the eyelid and constricts the pupil of the eye.Its easily compressed by brain tumors or by increased intracranial pressure causing a sluggish reaction to light. Also damage may result in ptosis of the eyelid.

Question 4

CN IV

Answer 4

Trochlear nerve- a motor nerve that innervates one of the extrinsic muscles of the eyeball, helping move the eyeball.Damage may cause double vision and inability to rotate the eye properly.

Question 5

CN V

Answer 5

Trigeminal nerve- A mixed nerve with 3 branches supplying the facial region. The 2 sensory branches carry info regarding touch, pressure, and pain from the face, scalp, eye and teeth to the brain. THe ophthalmic branch of the trigeminal nerve detects sensory info from the cornea.Nerve damage causes loss of sensation and impaired movement of the mandible. Also causes trigeminal neuraligia, or Tic douloureux.

Question 6

CN VI

Answer 6

Abducens nerve- a motor nerve that, like the trochlear, controls the eye movement by innervating only one of the extrinsic eye muscles. Nerve damage prevents a lateral rotation of the eye; at rest the eye drifts medially (toward the nose)

Question 7

CN VII

Answer 7

Facial Nerve- A mixed nerve that preforms mostly motor functions. It is called the nerve of facial expression. It allows you to smile, frown, and “ make other faces”. It also stimulates the secretetion of saliva and tears. Its sensory function is taste. If damaged can caused bells palsy .

Question 8

CN VIII

Answer 8

Vestibulocochlear nerve- A sensory nerve that carries info for hearing and balance from the inner ear to the brain. The vestibular branch of this nerve is responsible for equilibrium or balance and the cochlear branch is responsible for hearing. Damage may cause loss of hearing or balance or both.

Question 9

CN IX

Answer 9

Glossopharyngeal nerve- Mixed nerve that carries taste sensation from the posterior tongue to the brain. Motor fibers stimulate the secretion of salivary glands in the mouth. Other motor fibers innervate the throat and aid in swallowing, Also associated with the gag reflex. A secondary function of this nerve involves regulation of blood pressure via the baroreceptor reflex

Question 10

CN X

Answer 10

Vagus nerve- A mixed nerve that innervates the tongue, pharynx (throat) larynx (voice box) and many organs in the thoracic and abdominal cavities (lungs,stomach, intestines) Vagus literally means wanderer. Also participates in the regulation of blood pressure via the baroreceptor reflex. Nerve damage causes hoarseness or loss of voice, impaired swallowing and diminished motility of the digestive tract. Damage to both vagus nerves can be fatal.

Question 11

CN XI

Answer 11

Accessory nerve- A motor nerve that supplies the sternocleidomastiod and the trapezius muscles. thereby controling movement of the head and shoulder regions. Damage impairs your ability to shrug your shoulders and rotate your head.

Question 12

CN XII

Answer 12

Hypoglossal nerve- a motor nerve that controls movement of the tongue , thereby affecting speaking and swallowing activities. Damage causes the tongue to deviate toward the injured side.