Cranial Nerves Flashcards
1) How many cranial nerves are there?
2) Where do they emerge?
3) Where do they exit?
4) What are some differences of cranial nerves in contrast to spinal nerves?
1) 12 pairs
2) from the brain
3) through the foramina in the floor of the cranial cavity
4) individual cranial nerves differ in their fiber type composition
- regional overlap - multiple nerves innervate the same region or structure
- some lack a sensory ganglion
- have single roots
5) What two additional fiber types do cranial nerves have?
6) Describe the originnal fiber types we learned?
7) What was the additional fiber type formerly recognized?
5) SSA - Special Somatic Afferent = vision, hearing
SVA - Special Visceral Aafferent = olfaction, taste
6) GSA - Geveral Somatic Afferent = face, mouth
GVA - General Visceral Afferent = phyarnx, larynx
SE - Somatic Efferent = skeletal muscles
VE - Visceral Efferent = parasympathetic
7) SVE - Special Visceral Efferent = skeletal muscles derived from pharyngeal arches
1) Vomeronasal Nerve
action:
exit:
nerve fiber:
2) Describe nerve pathway
3) Describe action
1) selective smell (pheromone detection)
cribiform plate
SVA - somatic visceral afferent
2) from vomeronasal organ traverse the nasal cavity and penetrate the cribiform plate to synapse in accessory olfactory bulb
3) detects pheromones (odors that elicity sexual behavior) ; flehmen rxn associated with vomeronasal activity
1) Pnemonic
2) Name nerves for each letter
1) Oh Oh Oh, To Touch A Female’s Vagina Gives Vinny A Hard-on
2) Olfactory, Optic, Occulomotor, Trochlear, Trigeminal, Abducent, Facial, Vestibularcochlear, Gloosopharyngeal, Vagus, Accessory, Hypoglossal
1) Nerve I :
Action:
Nerve Fiber:
Location:
Exit:
1) Olfactory Nerve
Smell
SVA - somatic visceral afferent
neuron cell bodies located within olfactory epithelium on ethmoidal labyrinth
cribiform plate
Nerve II:
Action:
Fiber Type:
Location:
Exit:
Optic Nerve
vision
SSA - special somatic afferent
cell bodies are in the retina (the “nerve” is a CNS tract enveloped by meninges)
optic foramen
1) Nerve III:
2) Action:
3) Fiber Type:
4) Location:
5) Exit:
1) Occulomotor Nerve
2) eye movement and pupil constriction
3) SE - somatic efferent and VE - visceral efferent
4) SE - 4 extrinsic eye muscles, skeletal (dorsal, medial and ventral rectus; ventral oblique)
VE - intrinsic eye muscles, smooth (ciliary body - accomodation and iris - constrict pupil)
5) orbital fissure
1) Nerve IV:
2) Action:
3) Fiber Type:
4) Location:
5) Exit:
1) Trochlear Nerve
2) rotates eye
3) SE - somatic efferent
4) dorsal oblique
5) orbital fissure
1) Nerve V
2) Action and fiber type:
3) Divisions and Location
5) Exit
1) Trigeminal Nerve
2) sensory to face (GSA - general somatic afferent); muscles of mastication (SE - somtic efferent)
3) Opthalmic Nerve - orbit, cornea, eyelids, skin medial to eye
Maxillary Nerve - both lids lateralkly, upper jaw, teeth, lips, nose and nasal cavity
Mandibular Nerve - lower jaw, teeth, tongue, temporal region skin, muscles of mastication
5) opthalmic - orbital fissure
maxillary - round foramen and alar canal
mandibular - oval foramen
1) Nerve VI
2) Action
3) Fiber Type
4) Location
5) Exit
1) Abducent Nerve
2) lateral gaze and 3rd eyelid protrusion
3) SE - somatic efferent
4) lateral rectus and retractor bulbi
5) oribgtal fissure
1) Nerve VII
2) Action
3) Fiber Type
4) Location
5) Exit
1) Facial Nerve
2) facial expression, taste, secretions (saliva, lacrimal adn nasal)
3) SVA - special visceral afferent
GSA - general somatic afferent
VE - visceral efferent
SE - somatic efferent
4) SVA - taste buds of rostral 2/3rds of tongue (lingual branch)
GSA - rostral surface of pinna
VE - nasal glands, lacrimal gland, sublingual and mandibular salivary glands
SE - muscles of facial expression (ears, eyelids, nose and lips)
5) internal acoustic meatus –> stylomastoid f.
1) Nerve VIII
2) Action
3) Fiber Type
4) Location
5) exit
1) Vestibulocochlear Nerve
2) hearing, head acceleration
3) SSA - special somatic afferent
4) within petrous part of temporal bone (middle and inner ear)
hearing - axons from bipolar cell bodies in spiral ganglion of cochlea
acceleration - bipolar cell bodies in vestibular ganglion, associated with vestibular apparatus
5) internal acoustic meatus
1) Nerve IX
2) Action
3) Fiber type
4) Location
5) Exit
1) Glossopharyngeal Nerve
2) taste, pharynx and middle ear sensation; saliva
3) SVA - special visceral afferent
GVA - general visceral afferent
VE - visceral efferent
4) SVA - taste buds at caudal 1/2 of tongue
GVA - receptors in pharynx, middle ear, and carotid sinus and carotid body
VE - parotid and zygomaic salivary glands
5) jugular foramen
1) Nerve X
2) Action
3) Fiber Type
4) Location
5) Exit
1) Vagus Nerve
2) voice, cough, swallow, regurgitation…etc
3) SE - somatic efferent
VE - visceral efferent
GVA - general visceral afferent
GSA - general somatic afferent
SVA - special visceral afferent
4) SE - muscles of larynx, pharynx and esophagus (voice, cough, swallow and regurgitation
VE - thoracic and abdominal viscera (postganglion neurons in terminal ganglion)
GVA - receptors in viscera and in larynx/pharynx
GSA - skin of external auditory meatus via branch to facial nerve
SVA - taste in region of pharynx
5) jugular foramen
1) Nerve XI
2) Action
3) Fiber Type
4) Location
5) Exit
1) Accessory Nerve
2) neck movement
3) SE - somatic efferent
4) neck muscles - trapezius, omotransverarius, cleidocephalicus, sternocephalicus
5) jugular foramen
