cranial nerves Flashcards
Name all 12 cranial nerves
Olfactory Optic Occulomotor Trochlear Trigeminal Abducens Facial Vestibulocochlear Glossopharyngeal Vagus Accessory Hypoglossal Oh Oh Oh To Touch And Feel (a) Virgin Girls Vagina Ah Heaven
CNI, where does it exit, what modality is it, function, location of nuclei and major central projections?
Olfactory, exits cribriform plate, modality = sensory (special visceral sensory (senses derived from endoderm)). Location of nuclei in olfactory bulb.
Course transmits special sensory info from the nasal epithelium to the primaru olfactory cortex of the brain. in temporal lobe.
Axons from olfactory receptors bundle to penetrate small foramina in the cribriform plate of ethmoid bone. Anterior cranial fossa has a groove the olfactory bulb lays within. Bulb contains mitral cells synapsing with olfactory nerves, 2nd order neurons then pass posteriorly into olfactory tracts. This travels on the inferior surface on the frontal lobe. Olfactory cortex sends projections to many other areas including memory.
CNII where does it exit, what modality is it, function, location of nuclei and major central projections?
Optic, exits optic canal, sensory (special, somatic, sensory) senses derived from the ectoderm. For vision, nuclei in lateral geniculate nucleus. Transmission of SS info fom retina to primary visual cortex in occipital lobe. Optic nerve formed by axons of retinal ganglion cells receiving impulses from rods and cone receptors. Nerve leaves via optic canal a passage through sphenoid bone. Within middle cranial fossa, optic nerves from each eye form the optic chiasm. Fibres from medial half of each retina cross over to contralateral optic tract whereas fibres from lateral halves remain ipsilateral.
So right optic tract: contains fibres from right temporal retina and left medial retina.
Each optic tract travels to corresponding cerebral hemis to reach lateral geniculate nucleus, a relay system in the thalamus, fibres synapse here. Axons then carry from LGN to visual cortex via optic radiation - pathway.
CNXI where does it exit, what modality is it, function, location of nuclei and major central projections?
Spinal accessory, exits via jugular foramen, motor GSM and SVM modality. GSM - trapezius and sternocleidomasteoid.
Location of nuclei: cranial and spinal roots (medulla and spinal cord).
Motor fibres originate in medulla, joined by sympa fibres from crnial cervical ganglion which enter via foramen magnum. Exits skull via jugular foramen with CNIX and X, divides into dorsal and vental branches to innervate muscles of the shoulder
CNXII where does it exit, what modality is it, function, location of nuclei and major central projections?
Hypoglossal, exits via hypoglossal canal, modality = motor GSM. Function = intrinsic and extrinsic tongue muscles exc palatoglossus.
Location of nuclei = caudal medulla.
Exits cranium through hypoglossal canal. passes rostrally between CNX and XI and enters tongue ventrally to CN IX dividing deep and superficial branches ramifies within tongue to innervate ex/ext muscles.
Which CNs exit skull via jugular foramen?
CN IX, X, XI.
Which CNs exit the skull via superior orbital fissure?
CN III, IV, V1 (opthalmic) of V and VI
ALL EYE ONES BASICALLY except for optic
Where does maxillary V2 of V exit via?
Rotundum
Where does mandibular V3 of V exit via?
Ovale
Which CNs exit via internal acoustic meatus?
CNVII and CNVIII
Which CN does taste from anterior 2/3 of tongue?
Facial
Which CN does taste from posterior 1/3 of tongue
Glossopharyngeal
What modalities does occulomotor do?
Motor - GSM skeletal muscles and GVM smooth muscles.
GSM - 4 extrinsic muscles and levator palpbrae superioris
GVM pupillary sphincter
What’s the location of CN3 nuclei?
Occulomotor nucleus
