cranial nerves Flashcards
names of the cranial nerves
Only - Olfactory
One - Optic
Of - Oculomotor
The - Trochlear
Two - Trigeminal
Athletes - Abducens
Felt - Facial
Very - Vestibulocochlear
Good - Glossopharyngeal
Victorious - Vagus
And - Accessory
Healthy - Hypoglossal
which nerves are for smell and sight
olfactory and optic (I&II)
which nerves are for moving eyeballs
oculomotor, trochlear, abducens (III&IV&VI)
which nerves are for touch and movement of anterior 1/2 of head
trigeminal and facial (V&VII)
which nerves are for hearing and balance
vestibulochochlear
which nerves are for touch and movement of posterior 1/2 of head
glossopharyngeal, vagus (IX&X)
which nerves are for shrugging muscles
accessory (XI)
which nerves are for the tongue
hypoglossal (XII)
which are the parasympathetic fibres
III,VII,IX,X
what are the 4 fibre types
- general sensory
- special sensory
- somatic motor
- parasympathetic
general sensory fibre
sense of touch
special sensory fibre
smell, sight, taste, hearing and balance
somatic motor fibre
under conscious control
parasympathetic fibre
both afferent and efferent
olfactory nerve - CNI
- function: carries sense of smell from the olfactory mucosa to the brain
- one fibre type is smell (special sense)
- it exists the cranial cavity via cribriform plate
- originates as an extension of the telencephalon
- sensors in the superior part of the nasal cavity
optic nerve - CNII
- function: deliver sense of sight to the brain
- 1 fibre type: special sense (sight)
- emerges from the brain as the optic tract - from the diencephalon
- exits cranial cavity via optic canal
- sensors in retina
Oculomotor nerve - CNIII
- function: moves muscles in the eyeball sockets that move the eye around and lift up the eyelid (extrinsic eye)
- secondary function: parasympathetic with synapse on a ganglion behind eye to constrict the pupil (intrinsic eye)
- is a motor cranial nerve
- emerges from the anterior surface of the midbrain
trochlear nerve - CNIV
- 1 fibre type: somatic motor function
- function: innervation to superior oblique, an extrinsic muscle of the eye
- emerges from the posterior surface of brainstem
- exits cranial cavity via superior orbital fissure
- target in orbit
abducens nerve - CNVI
- function: innovates the muscle that abducts the pupil
- 1 fibre type: somatic motor
- goes to 1 of the 6 muscles in the eye - the lateral rectus muscle
- originates between pons and medulla
- exits cranial cavity via superior orbital fissure
trigeminal nerve - CNV
- has 3 divisions: ophthalmic division, maxillary division, mandibular division
- 2 fibre types: general somatic sensory and branchial motor
- function: sensation across the face comes and anterior scalp, moto to muscles of mastication
- emerges from the middle of the pons
- synapses are in the trigeminal nuclei
facial nerve - CNVII
- has all four fibre types
- emerges from the pons-medullary junction
- leaves cranial cavity at the internal acoustic meatus
- function: innervation of facial muscles, taste of anterior 2/3rds of tongue
vestibulocochlear nerve - CNVIII
- function is to give hearing and balance
- emerges from the pons-medullary junction
- runs parallel to the facial nerve
- exits through the internal acoustic meatus
- sensors in inner ear in temporal bone
glossopharyngeal nerve - CNIX
- general function is being the general sensory nerve for the posterior part of the head
- originates from pons-medullary junction
- has all 4 fibre types
- special sense component is taste to the posterior 1/3rd of the tongue
- exits at jugular foramen
vagus nerve - CNX
- originates from medulla
- exits at jugular foramen
- supplies parasympathetic innovation to the viscera of the thorax and abdomen, motor of pharynx and larynx, taste to epiglottis
- has all 4 fibre types
Accessory nerve - CNXI
- originates from lateral aspect of spinal cord and brainstem
- exits through the jugular foramen
- 1 fibre type: general somatic motor
- function: innervation of the the sternocleidomastoid-mastoid and trapezius muscle for elevation of the scapula and clavicle
- targets in neck and back
hypoglossal nerve - CNXII
- function: innervation to the muscles of the tongue
- originates from medulla
- travels through the hypoglossal canals that are immediately anterior to the foramen magnum
- runs underneath the tongue for supply
- exits cranial cavity via hypoglossal canal
sensory of motor functions (follows order of mnemonic for nerves)
Some - sensory
Say - sensory
Marry - motor
Money - motor
But - both
My - motor
Brother - motor
Says- sensory
Big - both
Brains - both
Matter - motor
More - motor
opthalmic division - CN V1
the somato-sensation for the tip of the nose, above the corner of the eye to the top of the head
maxillary division - CN V2
- sensation for the eye to the corner of the mouth
- is overlying the maxilla
mandibular division - CN v3
- sensation for the edge of the chin up to the corner of the mouth
- sits over the mandible
- the only part of the trigeminal nerve that carries motor route
- cervical nerves are from below the chin
what is the motor route of the trigeminal nerve
- the muscle of mastication
- temporalis, massitor, medial and lateral terigoids, tensor tympani, tensor veli palatini
where do the divisions of the trigeminal nerve leave
- V1: superior orbital fissure
- V2: foramen rotundum (inferior to the orbit and above oral cavity)
- V3: foramen ovale (through base of skull close to the jaw joint)
what are the branches of the facial nerve
- parotid plexus
- posterior auricular nerve
- chroda tympani
- greater petrosal nerve
where is the internal acoustic meatus located
in the petrous temporal bone
what is the somatic motor function of the vagus nerve
all of the muscles of the voice box and all the muscles of the pharynx
what is the special sensation of the vagus nerve
taste in the back of the throat on the epiglottis
where is the general sense of the vagus nerve
part of the area posterior to the external ear
what is the somatic pathway into the head
- derive from the thoracic and lumbar regions of the spine
- travel up and synapse in the sympathetic chain (either side of vertebral column)
- cross onto internal carotid artery and become plexiform
- they generally distribute with the arteries that targets are in the head
