Summary of the cranial nerves Flashcards
what are the cranial nerves?
set of 12 paired nerves that arise directly from the brain
what are the first 2 nerves and where do they arise from?
olfactory (I) + optic (II)
arise from cerebrum
what is the cerebrum?
anterior part of the brain, located in the front area of the skull and consisting of two hemispheres
where do the remaining 10 cranial nerves arise from?
brainstem (III-XII)
which part of the brainstem can cranial nerves III-XII arise from?
midbrain, pons or medulla
or from a junction between 2 parts
where does the trochlear nerve (IV) arise?
from posterior side of midbrain
what is special about the trochlear nerve (IV)?
has the longest intracranial length of all the cranial nerves
where does the oculomotor (III) nerve arise?
arises from the midbrain-pontine junction
where does the trigeminal (V) nerve arise?
pons
which nerves arise from the pontine-medullar junction?
abducens, facial, vestibulocochlear (VI-VIII) 6-8
which nerves arise POSTerior to the olive of medulla oblongata?
glossopharyngeal, vagus, accessory (IX-XI) 9-11
which nerves arise ANTerior to the olive of the medulla oblongata?
hypoglossal (XII)
how are the cranial nerves numbered?
by their location on the brain stem (superior to inferior, then medial to lateral)
and the order they exit from the cranium (anterior to posterior)
what is a mnemonic to remember the 12 cranial nerves?
Oh Oh Oh To Touch And Feel A Girl’s Vagina, Ah Heaven
what are the 12 cranial nerves?
Olfactory Optic Oculomotor Trochlear Trigeminal Abducens Facial vestibulocochleAr Glossopharyngeal Vagus Accessory Hypoglossal
which foramina does the olfactory nerve (CN I) leave the skull base?
cribriform plate
which foramina does the optic nerve (CN II) leave the skull base?
optic canal
which nerves leave the skull base at ‘superior orbital fissure’?
oculomotor nerve (CN III) 3 trochlear nerve (CN IV) 4 opthalmic nerve (CN V1) 5.1 abducens nerve (CN VI) 6
where does the maxillary nerve leave the skull base? nerve root?
foramen rotundum (CN V2)
where does the mandibular nerve leave the skull base? nerve root?
CN V3
foramen ovale
which nerves leave the skull base via the ‘internal acoustic meatus’?
facial nerve (CN VII) 7 vestibulocochlear nerve (CN VIII) 8
which nerves leaves the skull base via the jugular foramen?
glossopharyngeal nerve (CN IX) 9 vagus nerve (CN X) 10 accessory nerve (CN XI) 11
where does the hypoglossal nerve (CN XII) leave the skull base?
hypoglossal canal (by the foramen magnum)
which are the only cranial nerves to pass through canals?
cranial nerves with the number 2 in them (optic - 2, hypoglossal - 12) exit through the canal of the SAME NAME
