Cranial nerves

Question 1

CN I

Answer 1

Olfactory, sensory
- enters through cribiform plate
- sends projections to the primary olfactory cortex in the temporal lobe near the uncus and parahippocampus
- no relay with the thalamus

Question 2

CN II

Answer 2

Optic, sensory
- enters thorough optic canal
- sends projections to the primary visual cortex in the occipital love at the calcarine tissue
- relays with LGN

Question 3

CN III

Answer 3

Oculomotor, motor
- exits through superior orbital fissure
- parasympathetic fibers: edinger-Westphal nucleus —> cilliary ganglion —> ciliary body and pupillary constrictor muscles

Question 4

CN IV

Answer 4

Trochlear, motor
- exits through superior orbital fissure
- only nerve to emerge from posterior surface of brain stem
- innervated superior oblique muscle

Question 5

CN V

Answer 5

Trigeminal, sensory and motor
- emerges from the pons
- V1 - opthalmic nerve - enters through superior orbital fissure, innervates upper face
- V2 - maxillary nerve - enters through Foramen rotundum, innervates middle face and upper teeth
- V3 - mandibular nerve- enters through Foramen ovale, innervates lower teeth and anterior 2/3 of tongue
relays with VPM of thalamus to primary somatocensory cortex (postcentral gyrus)

Question 6

CN VI

Answer 6

Abducen, motor
- exits between pons and medulla to the superior orbital fissure
- innverates lateral rectus

Question 7

CN VII

Answer 7

Facial, sensory and motor
- Sensory - taste from anterior 2/3 of tongue , enters skull through internal acoustic meats
- Motor - muscles of facial expression and stapedius, exits pons to stylomastoid Foramen
Parasympathetic fibers: pterygopalatine and submandibular to glands (salivary)

Question 8

CN VIII

Answer 8

Vestibulocochlear, sensory
- enters through internal acoustic meatus
- hearing from cochlea
Auditory fibers —> MGN —> primary auditory cortex of superior temporal gyrus

Question 9

CN IX

Answer 9

Glossopharyngeal, sensory and motor
- Sensory - taste from posterior 1/3 of tongue
- Motor - muscles of pharynx, exits medulla and goes into jugular Foramen
Parasympathetic fibers: inferior salivary nucleus —> otic ganglion —> parotid gland

Question 10

CN X

Answer 10

Vagus, sensory and motor
- Sensory - neck, thorax, abdomen, pelvis, enters through jugular Foramen
- Motor - muscles of palate, pharynx, larynx, enters through jugular Foramen
Parasympathetic fibers: dorsal motor nucleus —> terminal ganglia —> peripheral targets

Question 11

CN XI

Answer 11

Spinal accessory, motor
- enters through Foramen magnum and exits through jugular Foramen
- neurons in spinal cord

Question 12

CN XII

Answer 12

Hypoglossal, motor
- exits medulla and goes to hypoglossal canal
- innervates tongue

Question 13

Cribiform plate

Answer 13

CN I olfactory

Question 14

Optic foreman

Answer 14

CN II optic

Question 15

Superior orbital fissure

Answer 15

Under the ridge
- CN III oculomotor
- CN IV trochlear
- CN V (V1) trigeminal
- CN VI abducens

Question 16

Foreman ovale

Answer 16

CN V (V3) trigeminal

Question 17

Foramen rotundum

Answer 17

CN V (V2) trigeminal

Question 18

Internal acoustic meatus

Answer 18

• CN VII facial
• CN VIII vestibulocochlear

Question 19

Jugular foramen

Answer 19

• CN IX glossopharyngeal
• CN X vagus
• CN XI spinal accessory

Question 20

Hypoglossal canal

Answer 20

CN XII Hypoglossal