Cranial Nerves

Question 1

Which part of the nervous system are the CN part of?

Answer 1

Peripheral

Question 2

How many cranial nerves are there?

Answer 2

12

Question 3

What are the first 5 CN?

Answer 3

CNI - Olfactory
CNII - Optic
CNIII - Oculomotor
CNIV - Trochlear
CNV - Trigeminal

Question 4

What are the divisions of the trigeminal nerve?

Answer 4

CNVa - Opthalmic
CNVb - Maxillary
CNVc - Mandibular

Question 5

What are CNVI - CNXII called?

Answer 5

CNVI - Abducent 
CNVII - Facial 
CNVIII - Vestibulocochlear 
CNIX - glossopharyngeal 
CNX - Vagus
CNXI - Accessory 
CNXII - Hypoglossal

Question 6

What are the possible sensory functions of cranial nerves?

Answer 6

• general sensation
• sensation from organ
• unique sensation such as taste and smell e.g. CNIX

Question 7

What are the possible motor functions of cranial nerves?

Answer 7

• striated muscle innervation

- glands and smooth muscle innervation

Question 8

What is the function of the facial nerve?

Answer 8

innervates nerves of facial expression but not skin of face (innervated by trigeminal)

Question 9

What are the cranial nerve nuclei?

Answer 9

• collection of cell bodies within the cranial nerves

Question 10

Where are the CN bodies of CNI located?

Answer 10

olfactory epithelium within the nasal cavity

Question 11

Where are the CN bodies of CNII located?

Answer 11

retina

Question 12

Where are the CN bodies of CNIII-CNXII located?

Answer 12

within brainstem either midbrain, pons or medulla oblongata

Question 13

What can happen if there is a fracture of the cribriform plate?

Answer 13

leaking of CSF from nasal canal (clear fluid)

Question 14

What nerve is primarily affected by a pituitary tumour?

Answer 14

Optic nerve due to pituitary swelling pressing on optic chiasm

Question 15

Where is the oculomotor nerve located?

Answer 15

anterior aspect of midbrain

Question 16

Where is the trochlear nerve and how can it easily be differentiated from CNIII?

Answer 16

posterior aspect of midbrain, smaller than the oculomotor

Question 17

What muscles are innervated by oculomotor nerve?

Answer 17

• extraocular muscles
• superior, medial and inferior rectus muscles
• levator superioris
• inferior oblique

Question 18

trochlear nerve innervates what muscle?

Answer 18

superior oblique

Question 19

Where is the trigeminal nerve located?

Answer 19

lateral aspect of pons

Question 20

What nerves emerge from ponto-medullary junction?

Answer 20

• abducent (more medial than other nerves)
• facial
• vestibulocochlear

Question 21

Which structure does the glossopharyngeal nerve emerge from?

Answer 21

medulla oblongata

Question 22

What other nerve emerges at the same location as glossopharyngeal?

Answer 22

vagus

Question 23

Where does the spinal accessory nerves emerge from?

Answer 23

upper region of spinal cord

Question 24

Where does the hypoglossal nerve emerge from?

Answer 24

medulla oblongata (more medial than CNIX)

Question 25

What does the hypoglossal nerve innervate?

Answer 25

Intrinsic muscles of tongue

Question 26

What opening of the skull does the opthalamic

Answer 26

superior orbital fissure