anatomy: cranial nerves Flashcards
What is cranial nerves
Nerves that are directly attached to a part of the brain
What cranial nerves attach directly to the forebrain & where
CN I & II
Cerebrum
What cranial nerves attach to the brainstem
CN III to XII
What cranial nerves attach directly to the midbrain
CN III & IV
What cranial nerves attach directly to the pons
CN V, VI, VII & VIII
What cranial nerves attach directly to the medulla
CN IX, X, XI & XII
What is the 12 cranial nerves
Oh: olfactory
Oh: optic
Oh: oculomotor
To: trochlear
Touch: trigeminal
And: abducens
Feel: facial
Very: vestibulocochlear
Good: glossopharyngeal
Velvet: vagus
Such: accessory
Heaven: hypoglossal
What is the primary function, origin, structures it pass through & destination of CN I
Function: smell
Origin: receptors of olfactory epithelium
Passing structures: olfactory foramina in
cribriform plate of ethmoid
plate
Destination: olfactory bulb
What is the primary function, origin, structures it pass through & destination of CN II
Function: vision
Origin: ganglionic cells in retina of eye
Passing structures: optic canal of sphenoid Destination: diencephalon via optic chiasma
What is the primary function, origin, structures it pass through & destination of CN III
Function: eye motor
Origin: midbrain at oculomotor nucleus & parasympathetic
Passing structures: superior orbital fissure of sphenoid
Destination: somatic motor to superior,
inferior & medial rectus muscles, inferior oblique & levator superioris & visceral motor to intrinsic eye muscles
What is the primary function, origin, structures it pass through & destination of CN IV
Function: eye movement
Origin: trochlear nucleus in midbrain
Passing structures: superior orbital fissure of sphenoid & lateral cavernous sinus
Destination: superior oblique
What is the primary function, origin, structures it pass through & destination of CN V
Function: sensory & motor
Origin: sensory (V1-2) mixed (V3)
Passing structures: V1 superior orbital fissure, V2 foramen rotundum & V3 foramen ovale
Destination: sensory nuclei in pons & V3 muscles of mastication
What is the primary function, origin, structures it pass through & destination of CN VI
Function: eye movement
Origin: pons
Passing structures: superior orbital fissure of
sphenoid & cavernous sinus
Destination: lateral rectus
What is the primary function, origin, structures it pass through & destination of CN VII
Function: sensory & motor
Origin: sensory taste receptors & motor is motor nuclei of pons
Passing structures: internal acoustic meatus to
canal leading to
stylomastoid foramina
Destination: sensory to sensory nuclei of pons, somatic motor to muscle of facial expression& visceral motor to lacrimal gland & nasal mucous glands
What is the primary function, origin, structures it pass through & destination of CN VIII
Function: balance
& equilibrium (vestibular) & hearing (cochlear)
Origin: receptors of internal ear (vestibule- ganglion & nucleus & cochlea- organ of Corti & nucleus)
Passing structures: internal acoustic meatus of
temporal bones
Destination: vestibular & cochlear nuclei of
pons & medulla oblongata
What is the primary function, origin, structures it pass through & destination of CN IX
Function: sensory &
motor to head & neck
Origin: sensory to tongue, part of pharynx,
palate & carotid artery of
neck & motor to motor nuclei of medulla oblongata
Passing structures: jugular foramina between
occipital & temporal bones
Destination: sensory to sensory nuclei of medulla oblongata, somatic motor to pharyngeal muscles for swallowing & visceral motor to parotid gland
via otic ganglion
What is the primary function, origin, structures it pass through & destination of CN X
Function: sensory &
motor to thorax &
abdomen
Origin: sensory to pharynx, auricle, external acoustic meatus, diaphragm, & visceral organs & motor to motor nuclei of medulla oblongata
Passing structures: jugular foramina between
occipital & temporal bones
Destination: sensory to sensory nuclei & autonomic centers of medulla oblongata & visceral motor to muscles of palate, pharynx, digestive, respiratory & cardiovascular
system
What is the primary function, origin, structures it pass through & destination of CN XI
Function: muscles of
neck & upper back
Origin: motor nuclei of spinal cord & medulla oblongata
Passing structures: jugular foramina between occipital bone & temporal bones
Destination: internal branch to voluntary
muscles of plate, pharynx & larynx & external branch to
sternocleidomastoid & trapezius
What is the primary function, origin, structures it pass through & destination of CN XII
Function: tongue movement
Origin: motor nuclei of medulla oblongata
Passing structures: hypoglossal canals of
occipital bone
Destination: muscles of tongue
What is the course of CN II
Pass through optic canal & forms optic chiasma & continue as optic tracts ending in LGB & radiations go to end visual cortex
What is the course of CN III
Via interpeduncular fossa through lateral wall of cavernous sinus & enters orbits through superior orbit fissure dividing into superior & inferior division
Parasympathetic passes via inferior division
What is the course of CN X
Via jugular foramen passing within carotid sheath, oesophageal opening & plexuses
What is it called when you lose the ability to smell
Anosmia
What is the three instances where CN I is damaged
- Head injury: tear nerve (anterior cranial fossa injury)
- Leakage of CSF: tearing of meningeal covering of nerve
- Tumour at skull base
