Lecture 7 - cranial nerves

Question 1

Olfactory Nerve (I)

Answer 1

• originate - olfactory mucosa of nasal cavity
• passes through skull at cribriforum plate
• terminate - olfactory bulb
• sensory
• smell

Question 2

The Optic Nerve (II)

Answer 2

• originate - in dianncephalon
• passes through skull at optic foramen in sphenoid bone
• terminate - lamina cribrosa
• sensory
• visual

Question 3

The Oculomotor (III)

Answer 3

• originate in the ventral areas of the brainstem
• passes through skull at the superior orbital fissure in sphenoid bone
• related to eye movements
• motor

Question 4

Trochlear (IV)

Answer 4

• originate in the ventral areas of the brainstem
• passes through skull at the superior orbital fissure in sphenoid bone
• related to eye movements
• motor

Question 5

Abducens (VI) Nerves

Answer 5

• originate in the ventral areas of the brainstem
• passes through skull at the superior orbital fissure in sphenoid bone
• related to eye movements
• mixed

Question 6

The Trigeminal Nerve (V)

Answer 6

Three branches:
* Opthalmic - exits; superior orbital fissure, runs forward roof of orbit,
emerges through supraorbital foramen
* Maxillary - exit foramen rotundum, runs through floor of orbit & emerges through infraorbital foramen
* Mandibular - exits foramen ovale, enters mandibular
foramen

All originate from the ventrolateral
surface of the pons (brain stem)

Question 7

The Facial Nerve (VII)

Answer 7

• originates from the lateral part of the brainstem, pontomedullary junction
• passes into onternal acoustic meatus & exits through stylomastoid foramen
• gives 5 branches within parotid gland

Question 8

bell’s palsy

Answer 8

• symptoms result from high injury to facial nerve
• nerve supplies muscle function & sensation to face affecting ears, salivation, taste and facial expression

Question 9

Vestibulocochlear Nerve (VIII)

Answer 9

Consists of two branches
* Vestibular branch (balance)
* Cochlear branch (hearing)

enters cranium through internal acoustic meatus

Question 10

Glossopharyngeal Nerve (IX)

Answer 10

• Originates from the medulla oblongata.
• exits the skull through the jugular foramen.
• motor fibres innervate the stylopharyngeus muscle (of the pharynx)
• sensory to oropharynx and posterior tongue.

Question 11

Vagus Nerve (X)

Answer 11

• arises from medulla oblongata
• exits skull through jugular foramen
• sensory to external auditory meatus
• Motor fibres innervate the muscles of the larynx, respiratory passages, lungs, heart, oesophagus, stomach, small intestine, most of the large intestine & the gallbladder

Question 12

Accessory Nerve (XI)

Answer 12

• originates from both the medulla oblongata and from the spinal cord.
• emerge out through the jugular foramen.
• supplies : Trapezius & sternocleidomastoid muscles

Question 13

Hypoglossal Nerve (XII)

Answer 13

• originates in the medulla oblongata.
• exits the skull through the hypoglossal canal
• innervates the muscles of the tongue

Question 14

sensory, motor, mixed?

Answer 14

I. Olfactory - sensory
II. Optic - sensory
III. Oculomotor - motor
IV. Trochlear - motor
V. Trigeminal - mixed
VI. Abducens - motor
VII. Facial - mixed
VIII. Vestibulocochlear - sensory
IX. Glossopharyngeal - mixed
X. Vagus - mixed
XI. Accessory - motor
XII. Hypoglossal - motor