FINAL: cranial nerves Flashcards
CI olfactory n.: function, exit
Special sensory: smell (special visceral afferent)
- cribriform plate (ethmoid b.)
CI: what does it do in addition to enabling us to smell?
induces visceral responses via ANS (salivation)
CII optic n.: function, exit
S: vision (special somatic afferent)
- optic foramen (sphenoid b.)
CII: what is it formed by?
retinal ganglion axons that converge at optic disc (back of eye)
CII: how is it covered?
cranial meninges + subarachnoid space filled with CSF
CII: what happens when it reaches the optic chiasma? where do the fibers terminate?
- runs to brain (thalamus) via optic tracts
- most go to thalamus before travelling to occipital lobe (visual cortex)
- some end in sup. colliculi (sight reflexes)
Which fibers do the left and right optic tract contain from the eyes?
Left: medial from right eye, lateral from left
Right: medial from left, lateral from right
CIII occulomotor n.: function, exit
S (proprioception) / M (mainly M): eye muscles
- sup. orbital fissue (sphenoid b.)
CIII: what does it innervate?
- sup., inf., medial rectus m.
- inf. oblique m.
- levator palpabrae m.
- ciliary bodies m. of Lens
- iris (smooth m.): reflex somatic adjustment (proprioceptor)
CIII: within the superior orbital fissure the nerve divides into:
superior and inferior divisions: somatic fibers
- sup: levator palpebrae + sup. rectus
- inf: med. & inf. rectus + inf. oblique + also has presynaptic autonomic (parasympathetic) fibers to ciliary ganglion (affect iris and ciliary m.)
CIV trochlear n.: function, exit
S/M (mainly motor): sup. oblique m. (rotate down and laterally)
- sup. orbital fissure (sphenoid b.)
CIV: origin
superiolateral aspect of pons (only cranial n. emerging dorsally from brainstem)
What is diplopia?
double vision
CV1 Opthalmic n.: function, exit
S: eye, conjunctiva, lacrimal gland+sac, nasal mucosa, frontal sinus, external nose, upper eyelid, forehead and scalp
- sup. orbital fissure (sphenoid b.)
CV2 Maxillary n: function, exit
S: skin of face over maxilla including upper lip, maxillary teeth, nasal mucosa, maxillary sinuses and palate
- foramen rotundum (sphenoid b.)
CV3 Mandibular n: function, exit
S: skin over mandible/lower lip/side of head, mandibular teeth, mucosa of mouth and ant. 2/3 of tongue
M: muscles of mastication (masseter, temporalis, lat./med. pterygoid)
- foramen ovale (sphenoid b.)
CVI abducens n.: ORIGIN, function, exit
S/M (mainly motor): lat. rectus m.
- sup. orbital fissure (sphenoid b.)
- origin: btwn pons and medulla
CVII facial n.: function
S: taste (ant. 2/3 of tongue)
Somatic Motor: m. of facial expression + post. belly of digastric m. + stylohoid m. + stapedius m.
Parasympathetic Motor (ANS): submandibular/sublingual/lacrimal glands, mucous glands of soft palate/nose/paranasal sinuses
CVII: orgin, pathway, exit
- start: btwn pons and medulla
- exit: internal acousitc meatus, facial canal, then stylomastoid foramen (temporal b.)
- passes thru parotid gland after
CVIII vestibulocochlear n.: function, where it divides, location
S (special somatic afferent): equilibrim (vestibular division) + hearing (cochlear division)
- divides at internal acoustic meatus
- located in petrous portion of temporal b. at internal auditory meatus (does not exit skull)
- junction of pons and medulla
CIX glossopharyngeal n.: function
Sensory (special visceral afferent): taste (post. 1/3 of tongue)
Sensory (general visceral afferent): carotid sinus, carotid body, pharyngeal mucosa, palatine tonsil
Sensory (somatic afferent): post 1/3 of tongue, auditory tube, middle ear
Somatic Motor: stylopharygeus m.
Autonomic (parasympathetic) Motor: parotid + salivary glands
CIX: sensory function
proprioception of swallowing muscles + monitor BP, O2, CO2 in blood, breathing rate/depth
CIX: exit
Jugular foramen (petrous portion of temporal & occipital b.)
CX vagus n.: function
S: inf. pharynx, larynx, abdominal/thoracic viscera (afferent and efferent), taste from root of tongue, and taste buds on epiglottis
M: soft palate m., pharynx, intrinsic larynx m., palatoglossus m. (tongue)
