Cranial nerves

Question 1

What are the cranial nerves?

Answer 1

• 12 of them
• Motor + Sensory
• Clustered around base of cerebrum and brain stem

Question 2

I - Olfactory?

Answer 2

• Sensory
• From nose to temporal lobe + entorhinal cortex
• Function = smell

Question 3

II - Optic?

Answer 3

• Sensory
• From retina to lateral geniculate nucleus in thalamus + visual cortex
• Function = sight

Question 4

III - Occulomotor?

Answer 4

-Motor
-From mid brain to most muscles of the eye:
(superior rectus muscle, inferior rectus muscle, medial rectus muscle, inferior oblique muscle, levator palpebrae superioris)
-Function = eye movement

Question 5

IV - Trochlear?

Answer 5

• Motor
• From mid brain to superior oblique eye muscle
• Function = moves eyeball down and medially

Question 6

V - Trigeminal?

Answer 6

• Sensory and motor fibres.
• From pons to face (ophthalmic, maxillary, mandibular) and muscles of the jaw.
• Functions = sensation of the head and mastication.

Question 7

VI - Abducens?

Answer 7

• Motor
• From beneath 4th ventricle to lateral rectus muscle of eye.
• Function = abducts the eyeball.

Question 8

VII - Facial?

Answer 8

• Sensory, motor + parasympathetic.
• From sensory receptors to thalamus.
• From motor pons to muscles of facial expression.
• Functions = sensations, face movement, glands.

Question 9

VIII - vestibulocochlear?

Answer 9

• Sensory
• Vestibular and cochlear.
• From ear to vestibular (III, IV, VI cranial nerves).
• From ear to chochlear (thalamus, auditory cortex)
• Functions = body posture, balance, hearing

Question 10

IX - Glossopharyngeal?

Answer 10

• Sensory
• From receptors in tongue, pharynx ear to brain stem.
• Functions = taste, swallowing, gag reflex, salivary gland in cheek.

Question 11

X - Vagus?

Answer 11

• Sensory
• From pharynx, larynx, oesophagus, ear, blood vessels TO medulla.
• Function = autonomic control of visceral function.
• Motor
• From medulla to muscle of pharynx and larynx and oesophagus.
• Function = swallowing, control of speech.

Question 12

XI - Accessory?

Answer 12

• Motor
• Cranial is from medulla to muscles of soft palate, pharynx and larynx.
• Function = swallowing
• Spinal is from motor neurones C1 to C5 to X vagus nerve.
• Function = movement of head + neck.

Question 13

XII - Hypoglossal?

Answer 13

• Motor
• From medulla to muscles of the tongue
• Function = movement of tongue, chewing, sucking, swallowing.

Question 14

How to remember the 12 nerves?

Answer 14

Oh, Once One Takes The Anatomy Final, Very Good Vacations Are Heavenly!