Cranial Nerves - Prof Rea Flashcards
what are the 12 cranial nerves
olfactory
optic
oculomotor
trochlear
trigeminal
abducens
facial
vestibulocochlear
glossopharyngeal
vagus
spinal accessory
hypoglossal
what is the first cranial nerve
olfactory
what is the second cranial nerve
optic
what is the third cranial nerve
oculomotor
what is the fourth cranial nerve
trochlear
what is the fifth cranial nerve
trigeminal
what is the sixth cranial nerve
abducens
what is the seventh cranial nerve
facial
what is the eighth cranial nerve
vestibulocochlear
what is the ninth cranial nerve
glossopharyngeal
what is the tenth cranial nerve
vagus
what is the eleventh cranial nerve
spinal accessory
what is the twelfth cranial nerve
muscles of the tongue
what are the three main functional components of the cranial nerves
motor innervation to voluntary muscles
motor innervation to involuntary muscles
sensory
describe the motor innervation to voluntary muscles by cranial nerves
can either be somatic motor or branchial motor
which of the voluntary muscle innervations come from the pharyngeal arches
branchial motor
what are the involuntary muscles provided by the cranial nerves
sphincter papillae and lacrimal glands
describe the sensory component of cranial nerve innervation
sensation from the viscera, general sensation and special senses
what does the sphincter pupillae do
constrict the pupil
what do the lacrimal glands do
tear production
what are the pharyngeal arches remnants of
gills because we evolved from fish
why do pupils constrict in bright light
to protect the back of the retina
what is general sensation
touch pressure temperature and pain
what are special senses
taste
smell
sight
hearing
balance
which nerve fibres are capable of regeneration
olfactory
what are olfactory ensheathing cells used for
used in spinal cord injury patients to enable them to regain some function
what is anosmia
no smell
what can be injected into the patients with spinal cord injuries
olfactory ensheathing cells
describe the function of the olfactory nerve
special sensory for smell from the nasal mucosa of each nasal cavity, nasal septum and superior conchae.
has olfactory epithelium
describe the function of the optic nerve
special sensory for vision.
the nerve cell bodies are found in the retina and exit the orbital canal via the optic chiasm.
vision comes from the retina
what is multiple scelorosis
a demyelinated disease which can lead to disrupted vision
what is the optic chiasm
the crossing point of fibres of the left and right optic nerves.
some fibres stay on the same side, others cross over, and this happens at the chiasm.
what is myelin
fatty sheath that surrounds the axons of the nerve fibres.
how can MS affect vision
results in loss of myelin and this can result in weakness of the limbs and reduction of sight
in severe cases there can be complete loss of vision as the axon of the optic nerve is surrounded by myelin
which cranial nerve is a direct extension of the brain
the optic nerve
what are the extra ocular muscles
muscles that surround the eye and are responsible for movement of the eyeball itself
describe the sphincter pupillae
smooth muscle that constricts the eye as part of the pupillary light reflex
what does the ciliary muscle control
accommodation ie looing at far or near objects and focusing on things. it alters the shape of the lens, but not the pupillary size.
which muscles control pupil size
sphincter pupillae and dilatory pupillae
what is the ciliary ganglion
this is where the presynaptic and post synaptic fibres synapse.
where are the parasympathetic fibres of the eye distributed to
the sphincter pupillae and ciliary muscle
what can cause compression of the oculomotor nerve
aneurysm
diabetes
inflammation
trauma
what does the inferior oblique muscle do
move the eye upward and outward
what does the levator palpebrae do
hold the eyelids open
what does the medial rectus do
move the eye toward the nose
what does the ciliary muscle allow the eye to do
look both into the distance and close up
what are the muscles provided by the oculomotor nerve
superior rectus
medial rectus
inferior oblique
levator palpebrae superiosis
what delivers the parasympathetic innervation to the sphincter pupillae and ciliary muscle
the ciliary ganglion