Cranial nerves 1: Introduction, Eye movements and Autonomics Flashcards
what is the function of the olfactory nerve (1)
sense of smell
special visceral afferent
what is the function of the optic nerve (2)
sense of sight
special somatic afferent
what is the function of the occulomotor nerve (3)
eye movements
somatic efferent
p’symp visceral efferent in addition
what is the function of the trochlear nerve (4)
Eye movements
somatic efferent
what is the function of the trigeminal nerve
sensation- head and cavities
motor- muscles of mastication
also a carrier
what is the function of abducent nerve (6)
eye movements
what is the function of the facial nerve (7)
motor - muscles of facial expression
also taste (nervus intermedius)
what is the function of vestibulocochlear nerve (8)
hearing and balance
what is the function of glossopharyngeal (9)
sensation of posterior third of tongue and oropharynx
what is the function of the vagus nerve (10)
p’sympathetic visceral - heart, lungs, GI tract
what is the function of spinal accessory nerve
motor to sternocleidomastoid and trapezius
what is the function of hypoglossal (12)
motor to tongue
why might abduccens be stretched in raised intracranial pressure
passes upwards on the clivus
why might oculomotor be compressed in raised intracranial pressure
it lies superior and adjacent to the tentorium cerebelli
what nerves might be compromised in a circle of willis aneurysm
oculomotor (3)
passes between the posterior
cerebral and superior cerebellar branches of the circle of
Willis, before lying close to the posterior communicating
artery.
special visceral efferent
descending information to branchial muscles (mastication, pharynx and larynx)
special somatic afferent
sight, hearing, balance
general somatic afferent
sensory from the body
special visceral afferent
taste and smell
general visceral afferent
ascending information from heart, lungs, gut, etc
general visceral efferent
descending information to heart, lungs, gut
somatic efferent
descending motor to body
what nuclei are found in the midbrain (4)
mesencephalic trigeminal nucleus
edinger westphall (3)
occulomotor
trochlear
what nuclei are found in the pons (6)
chief sensory nucleus (5) motor trigeminal (5)
facial (7)
abducens (6)
superior salivatory (7) inferior salivatory (9)
what nuclei are found in the medulla
spinal trigeminal nucleus (5,7,9,10)
solitarius(8,9,10)
dorsal motor vagal nucleus (10)
ambiguous (9, 10)
spinal accessory (11)
hypoglossal (12)
what is the function of the spinal trigeminal nucleus
crude touch, temp and pain from ipsilateral face
receives input from 5,7,9,10
solitary nucleus
a series of purely sensory nuclei (clusters of nerve cell bodies) forming a vertical column of grey matter embedded in the medulla oblongata
contributes to autonomic regulation
cn 8, 9, 10 (7 is part of tract)
what are the inputs to the solitary nucleus
taste from ant tongue via facial
sensory from ear (auricular branch of vagus)
Chemoreceptors and mechanoreceptors in the carotid body via glossopharyngeal nerve, and aortic bodies via the vagus nerve
dorsal motor vagal nucleus (medulla, general visceral efferent)
parasympathetic vagal functions in the gastrointestinal tract, lungs, and other thoracic and abdominal vagal innervations.
nucleus ambiguous (9,10)
innervate the muscles of the soft palate, pharynx, and larynx which are strongly associated with speech and swallowing
also psymp to heart
what is the basal plate
found in the anterior part of the developing spinal cord, becomes the motor part of the spinal cord
found medially in the brainstem
opposite of alar plate
what is the sulcans limitans
hole in the developing spinal cord which later becomes the central canal
intermediate nerve
found between the motor component of the facial nerve and the vestibulocochlear nerve
sensory and psymp fibres of the facial nerve
what structures does the abducent nerve travel through
cavernous sinus
superior orbital fissure
tendinous ring
what structures does the trochear nerve pass through (arises dorsally)
cavernous sinus
superior orbital fissure
what structures does the occculomotor nerve pass through
cavernous sinus
superior orbital fissure
tendinous ring
what nerve can be damaged in raised intracranial pressure due to its proximity to the tentorium cerebelli
oculomotor
what nerve can be damaged in raised intracranial pressure due to it passing upwards on the clivus
abducent
why do the nerves for eye movement pick up sympathetic fibres
they pass close to the sympathetic fibres which form a plexus on the internal carotid artery
where is the superior orbital fissure
between the lesser and greater wings of the spenoid (lateral wall of orbit)
what wall of the orbit does the sphenoid bone make
lateral
what modalities does the occulomotor nerve contain
somatic motor
psymp from edinger westphal
sympathetics from the carotid plexus
what way does the eye turn in an occulomotor nerve injury (due to sup oblique and lateral rectus)
downwards and laterally
upper eyelid droops
sympathetic part of occulomotor
pupil dilation (nasocilliary) smooth muscle part of levator palpebrae superioris
parasympathetic part of occulomotor
synapses in the ciliary ganglion (from E-W nucleus)
pupil constriction
lens accommodation via cilliary muscle
what controls the lacrimal gland
psymp system
facial nerve
