Cranial Nerves Flashcards
Which part of the nervous system are the CN part of?
Peripheral
How many cranial nerves are there?
12
What are the first 5 CN?
CNI - Olfactory CNII - Optic CNIII - Oculomotor CNIV - Trochlear CNV - Trigeminal
What are the divisions of the trigeminal nerve?
CNVa - Opthalmic
CNVb - Maxillary
CNVc - Mandibular
What are CNVI - CNXII called?
CNVI - Abducent CNVII - Facial CNVIII - Vestibulocochlear CNIX - glossopharyngeal CNX - Vagus CNXI - Accessory CNXII - Hypoglossal
What are the possible sensory functions of cranial nerves?
- general sensation
- sensation from organ
- unique sensation such as taste and smell e.g. CNIX
What are the possible motor functions of cranial nerves?
- striated muscle innervation
- glands and smooth muscle innervation
What is the function of the facial nerve?
innervates nerves of facial expression but not skin of face (innervated by trigeminal)
What are the cranial nerve nuclei?
- collection of cell bodies within the cranial nerves
Where are the CN bodies of CNI located?
olfactory epithelium within the nasal cavity
Where are the CN bodies of CNII located?
retina
Where are the CN bodies of CNIII-CNXII located?
within brainstem either midbrain, pons or medulla oblongata
What can happen if there is a fracture of the cribriform plate?
leaking of CSF from nasal canal (clear fluid)
What nerve is primarily affected by a pituitary tumour?
Optic nerve due to pituitary swelling pressing on optic chiasm
Where is the oculomotor nerve located?
anterior aspect of midbrain
Where is the trochlear nerve and how can it easily be differentiated from CNIII?
posterior aspect of midbrain, smaller than the oculomotor
What muscles are innervated by oculomotor nerve?
- extraocular muscles
- superior, medial and inferior rectus muscles
- levator superioris
- inferior oblique
trochlear nerve innervates what muscle?
superior oblique
Where is the trigeminal nerve located?
lateral aspect of pons
What nerves emerge from ponto-medullary junction?
- abducent (more medial than other nerves)
- facial
- vestibulocochlear
Which structure does the glossopharyngeal nerve emerge from?
medulla oblongata
What other nerve emerges at the same location as glossopharyngeal?
vagus
Where does the spinal accessory nerves emerge from?
upper region of spinal cord
Where does the hypoglossal nerve emerge from?
medulla oblongata (more medial than CNIX)
What does the hypoglossal nerve innervate?
Intrinsic muscles of tongue
What opening of the skull does the opthalamic
superior orbital fissure
