ryan cranial nerves

CN I and II

which cranial nn are not true cranial nn?

they are extensions of the forebrain

why are CN I and II not true cranial nn?

CN III-XII

which cranial nn are true cranial nn?

CN III and IV

which cranial nn originate from the midbrain?

CN V-VIII

which cranial nn originate from the pons?

CN IX-XII

which cranial nn originate from the medulla?

CN IV (trochlear n)

what CN is the only nerve to leave the brainstem on the dorsal surface?

ventral

besides CN IV, all other CN emanate or enter what surface of the brainstem?

olfactory n

CN I name

optic n

CN II name

oculomotor n

CN III name

trochlear n

CN IV name

trigeminal n

CN V name

abducens n

CN VI name

facial n

CN VII name

vestibulocochlear n

CN VIII name

glossopharyngeal n

CN IX name

vagus

CN X name

accessory n

CN XI name

hypoglossal n

CN XII name

sensory

CN I composition

inferior aspect of cerebrum

CN I origin

cribriform plate of ethmoid

CN I foramina

smell from nasal mucosa

CN I function

sensory

CN II composition

posterior portion of thalamus, diencephalon

CN II origin

optic canal of sphenoid bone

CN II foramina

vision

CN II function

motor with parasympathetic output

CN III composition

ventral surface of midbrain, mesencephalon

CN III origin

superior orbital fissure

CN III foramina

motor innervation to all extrinsic eye muscle except the superior oblique and lateral rectus mm. motor innervation to intrinsic eye for pupillary constriction and accommodation

CN III function

motor

CN IV composition

dorsal surface of midbrain, mesencephalon

CN IV origin

superior orbital fissure (IV)

CN IV foramina

motor innervation to the superior oblique m of eye

CN IV function

mixed: sensory and motor

CN V composition

pons, metencephalon

CN V origin

1. ophthalmic division V1: superior orbital fissure

2. maxillary division V2: foramen rotundum of sphenoid bone

3. mandibular division V3: foramen ovale of sphenoid bone

CN V foramina

carry sensory information from face and jaws, motor innervation to the mm of mastication

CN V function

motor

CN VI composition

pons (metencephalon)

CN VI origin

superior orbital fissure (VI)

CN VI foramina

motor innervation to lateral rectus m of the eye

CN VI function

mixed: sensory, motor, and parasympathetic

CN VII composition

pons (metencephalon) at lateral aspect of pontomedullary junction

CN VII origin

internal acoustic meatus and stylomastoid foramen of temporal bone

CN VII foramina

motor for mm of facial expression, taste sensory for anterior 2/3 of tongue, parasympathetic for lacrimal, nasal, submandibular, and sublingual glands

CN VII function

sensory (VIII)

CN VIII composition

pons (metencephalon) at lateral pontomedullary junction

CN VIII origin

internal acoustic meatus of temporal bone

CN VIII foramina

carry 2 forms of special sense information

vestibular part carries equilibrium and balance info

cochlear part carries hearing information

CN VIII function

mixed: motor, sensory, and parasympathetic

CN IX composition

medulla, lateral to the olive (myelencephalon)

CN IX origin

jugular foramen

CN IX foramen

provides motor innervation to the stylopharyngeus m, provides parasympathetic innervation to the parotid gland via otic ganglion, carries general sensory from the pharynx, carries special sensory information for tase from the posterior 1/3 of tongue

CN IX function

motor: motor, sensory, parasympathetic (X)

CN X composition

medulla, lateral to olive and inferior to CN IX (myelencephalon)

CN X origin

jugular foramen (X)

CN X foramen

-pharyngeal n carries motor innervation to the mm of the pharynx (except tensor veli palatini m)

-superior laryngeal n carries sensory information from the larynx and piriform fossa and motor to a m of the larynx

-recurrent laryngeal n carries motor signals to the intrinsic mm of the larynx

-esophageal plexus sends autonomic signals to the smooth m of the esophagus

-cardiac plexus carries autonomic signals to the myocardium

CN X functions

motor (XI)

CN XI composition

medulla, lateral to olive and inferior to XN X (myelencephalon)

CN XI origin

jugular foramen (XI)

CN XI foramen

provide motor innervation to the sternocleidomastoid m and trapezius m

CN XI function

motor (XII)

CN XII composition

medulla (myelencephalon) between pyramid and olive

CN XII origin

hypoglossal canal of occiput

CN XII foramina

motor innervation to intrinsic and extrinsic mm of the tongue (except palatoglossal m)

CN XII function