Lab Quiz 6

Question 1

which cranial nerves are sensory, motor, or both?

Answer 1

CN I Olfactory: Some
CN II Optic: Say
CN III Oculomotor: Marry
CN IV Trochlear: Money
CN V Trigeminal: But
CN VI Abducens: My
CN VII Facial: Brother
CN VIII Vestibulocochlear: Says
CN IX Glossopharyngeal: Bigger
CN X Vagus: Brains
CN XI Spinal Accessory: Matter
CN XII Hypoglossal: Most

Question 2

what are the basic functions of the cranial nerves?

Answer 2

CN I Olfactory: transmits smell to CNS
CN II Optic: transmits visual information to CNS
CN III Oculomotor: visceral motor to the pupil
CN IV Trochlear: innervates superior oblique muscle
CN V Trigeminal: transmits somatic sensory afferent information from face and innervates facial muscles
CN VI Abducens: innervates lateral rectus muscle
CN VII Facial: motor innervation to the muscles of the face
CN VIII Vestibulocochlear: transmits hearing and balance information from inner ear
CN IX Glossopharyngeal: transmits tast and innervates pharyngeal muscles
CN X Vagus: supplies visceral motor information to descending colon, innervates throat muscles
CN XI Spinal Accessory: innervates trapezius and sternocleidomastoid, innervation to laryngeal muscles via vagus
CN XII Hypoglossal: innervates muscles of the tongue

Question 3

what does each section of the trigeminal sensory system do?

Answer 3

trigeminal lemniscus pathway: main sensory nucleus is associated with fine touch and proprioception from the face
trigeminothalamic tract pathway: spinal trigeminal nucleus is associated with pain and temperature information from face and head

Question 4

how do the trigeminal and facial nerves work together to innervates the face?

Answer 4

trigeminal nerve covers sensation to the face and is split into:
opthalamic: innervates the forehead area
maxillary: innervates the upper cheek and mouth
mandibular: innervates the lower jaw
facial nerve covers motor movements to the face

Question 5

how is the trigeminal sensory system like the medial lemniscus and anterolateral systems?

Answer 5

trigeminothalamic tract is like the substantia gelatinosa tract in the anterolateral system since it transmits pain information to the VPM of the thalamus
trigeminal lemniscus pathway is like the nucleus gracilis and nucleus cuneatus in the medial lemniscus pathway since it transmits fine touch and proprioception through the VPM of the thalamus

Question 6

what are some tests you can do to make sure each of the cranial nerves is working?

Answer 6

• olfaction (CN I olfactory)
• vision (CN II) Ophthalmoscopy exam (CN II optic)
• pupillary responses (CN II, III oculomotor)– II in III out (pupillary reflex)
• extra-ocular movements (CN III, IV trochlear, VI abducens)
• facial sensation and muscles of mastication (CN V trigeminal )
• muscles of facial expression and taste (CN VII facial)
• hearing and vestibular sense (CN VIII vestibulocochlear)
• palate elevation and gag reflex (CN IX glossopharyngeal, CN X vagus)
• muscles of articulation (CN V, VII, IX, X, XII hypoglossal)
• sternocleidomastoid and trapezius muscles (CN XI spinal accessory)
• tongue muscles (CN XII)