lecture 8: cranial nerve Flashcards
what is the function of olfact nerve
special sensory (or visceral afferent - smell)
the olfactory nevre fibers are collective known as what…
CI
In addition to enable us to smell, CI (olf) also induces what
visceral
responses via the ANS
give an example of how CI also induces visceral respinses via the ANS
salivation is initiated in response to the aroma of food
where dies the olf nerves lie
lie in the olfactory foramina
the octic nerve is in what psotiion in relation to the optic chaism
anteriir
when does the optic nerve beome the optic tract
when it goes posterior at the chiasm
what is the number for optic nerve
CII
what is the function of optic nerve
special sensory (somatic afferent - vision)
what is the optic nerve formed by
by retinal ganglion axons that
converge at the optic disc at the back of the eye
why is CII (optic) unique to the others
CII is unique in that it is surrounded by cranial meninges and
subarachnoid space is filled with CSF
what cranial nerve is surrounded by cranial meninges and
subarachnoid space is filled with CSF
optic
from the optic chaisms, where does the optic nerve run and how
it runs toward the brain (thalamus)
by way of the optic tracts
the fibers from the optic nerve all terminate in the thalamus?
falwe, some also go to others in the
superior colliculi (corpora quadrigeminis) before travelling to
the occipital lobe - visual cortex
which is the visible crotex
occipital lobe
the left optic tract recives what fibers from the left and right eyes
left optic tract receives lateral fibers from left eye and medial fibers from the right eye
right optic tract reviered lateral fibers from right eye and medial fibers from the left eye
which nerve is consiered the eye mover
occulomotor nerve
which is CIII
occulomotor nerver
occulomotoe’s function is mostly…
motor
why is the occulomtor “mainly” motor
because the pisition and the movement of eyes affect proprioception as well
CIII is the chief motor nerve to what
chief motor nerve to the ocular and extraocular
muscles
what is the chief motor nerve to the ocular and extraocular
muscles
CIII
what does the occuolo moteor nerve inenrvate
Superior, Inferior and Medial Rectus muscles
• Inferior Oblique muscle
• Levator Palpabrae muscle - Upper eyelid muscle
• Ciliary bodies (muscles) of the Lens
• Iris - is smooth muscle that acts like a sphincter to constrict and dilate
the pupil size
• Reflex Somatic Adjustment - Proprioceptor
what allows the occulomotor to be inporant for proprioception
because of the relex somatic adjustments
where does the occulomotor divide
in the sup orbital fisse
what happens to the occulomotor nerve in the sup orbital fissure
the nerve divides into the
superior and inferior divisions
what does the inferior division of the occulomot nerve carry fibers to
carries presynaptic autonomic fibers
to the CILIARY GANGLION
what is the function of the cilary ganglion
provides eye stability
the occulomotor lies on top of behind pons
on top of pons
which nerve acts like a pulley
trochlear
what is the function of trochlea
mainly motor
where does the trochlear nerve origionate
Originates from the superiolateral aspect of the pons
where does the trochlear nerve pass through
Superior Orbital Fissure
what does injury of the trochlear nerve do
inhibits the eyeball form turning out and
down (inferolaterally)
=diplopia
what is the only nerve to emerge dorsally from the brainstem
CIV
what is CIV
trochelar
which is the largest cranial nerve
trigeminal
which nerve is three fold
trigeminal
where is the trigem nerve located in relation to the pons
side of the pons
what are the 3 divisions of the trigemeinal nerve
ophthalmic
maxillary
mandibilar
where does the opthalmic divison pass trough
sup orbital fissure
the ophtlamic is a sensory or motor nevre
sensory
what does the ophltamic division supply
supplies the eyeball,
conjunctiva, lacrimal gland and sac, nasal mucosa, frontal sinus,
external nose, upper eyelid, forehead and scalp.
what type of nerve is the maxillary divison
sensory
where does the maxilalry nerve pass trhough
foramen rot.
where does maxillary division relay sensation
It relays sensation from the
skin of the face over the maxilla inluding the upper lip,
maxillary teeth, nasal mucosa, maxillary sinuses and palate.
what is the only trigeminal division to be a motor and sensory nerve
mandibular
where does the mandibular division pass trhough
foreamen ovale
true or false: trigeminal is a purly sensory nerve
false, because of mandibular division, it is also motor
what is the motor component of the mandibular division
muscles of mastication
what is the sensory component of mandibular divsion
skin over the mandible, lower lip and
side of head, mandibular teeth, mucosa of the mouth and the
ant two thirds of the tongue
what are the msucels of mastication
medial and lateral pteyoid, massterm, temporalis
true or false: the abducents is mainly motor
true
where does the abducens arrise and travel
arises between the pons and the medulla
on the brain and will travel through the SUPERIOR
ORBITAL FISSURE
what does the abductents innvervate
lateral rectus
which nerve ‘Abducts eyeball”
abducents
what is the function of the facial nerve
mixed
true or false: facial nerve is primarirly a motor nerve
true BUT it also carries spefical sensory (taste) fibers
where does facial nerve emergy and exit
CVII emerges btw the pons and medulla on the brain and exits
the skull though the internal acoustic meatus, facial canal and
finally the STYLOMASTOID FORAMEN
which nerve passes throug hthe parotid gland
facial nerve
what is CVII
facial
what is CVI
abdunents
true or false: the faicial nerve innervates the parotid
false, it just passes throguh ti
true or false: the facial nerve stays as one branch
false it divides
what does the facial nerve supply
muscles of facial expression, taste to ant.
two thirds of the tongue, parasympathetic innervation
to the submandibular, sublingual and lacrimal glands
and mucous glands of the soft palate, nose and
paranasal sinuses.
what is the function of vestibulocochlear
mixed (mainly sensory)
what is CVIII
vestibulocochlear
where is the vestibulocochlear nerve located
Located in the Petrous portion of the Temporal bone at
the internal auditory meatus
which nerve does not exit the skull
vestibilo
where is the vestibulo found
Found just below the Pons the junction of the Medulla
Oblongata
why does the vestibulo not exit the skull
because it supples brain and inner ear connection
where does the vestibilo nerve enter
enters the internal acoustic meatus
what does the vestibulo divid into when it enters the internal acostic meatus
divides into vestibular
(equilibrium) and cochlear (hearing) divisions
the function of the glosspharangeal is mixed?
true
what is the gloss. neerve responsible for (sensory)
responsible for conveying taste
from the posterior one third of the tongue
what does the gloss. supply
sensory innervation to the pharyngeal mucosa, palatine
tonsil, posterior one third of the tongue, auditory tube, middle
ear, carotid sinus and carotid body
what is CIX
glossopharangela
what is the only muscle innervated by CIX
stylopharygeus
what does CIX supply to the parotid and salivary glands
supples parasymp innervation
CIX supples para innervation to what
parotid and salivary glands
where does the gloospharangelan nerve pass through
Passes through the jugular foramen to exit the skull
what is the sensory function of the glossopharangeal nerve
Sensory function (proprioception of swallowing muscles, monitoring BP, O2, CO2 in bld, breathing rate and depth)
is the vafus nerve function, motor, sensory or mixed
mixed
what does vagus mean and why
“the wanderer” due to its extensive
innervation throughout the body
what nevre is CX
vagus
what is vagus nerve responsible for
sensation from the inferior pharynx, larynx and
thoracic and abdominal viscera
where from where is also carried by CX
Taste from the root of the tongue and taste buds located on the
epiglottis
what does vagus nerve innervate
Innervates the muscles of the soft palate, pharynx, the intrinsic
laryngeal muscles and the palatoglossus muscles of the tongue
the function of accesory is mainly…
motor
what nerve is CXI
accessory nerve
where does the accesory nerve origioatw
Originates from the medulla oblongata and spinal cord
whe spinal portion of the accesory nerve enters and exits where
The spinal portion enters the skull through the foramen
magnum, joins the medullary portion and exits through the
jugular foramen
what are the 3 nerves exitin at the jugular
vagus
glossopharangeal
aceesory
aCXi is responibsle for inenrvation of what
responsible for the motor innervation of the sternocleidomastoid
and trapezius muscles
the hypoglossal nerve is mainly sensory or motor
motor
the hypoglossal nerve arrises and leaves where
The hypoglossal nerve arises from the medulla and leaves the
skull from the medulla oblongata, through the hypoglossal canal
the hypoglossal nerve is joined temporarrily by what and what does it form
Joined temporarily by fibers from spinal nerves C1 and C2,
which form the superior limb of the ansa cervicalis
what does CXII (hypoglossal) supply innervation to
CXII supplies motor innervation to all the muscles of the tongue except palatoglossus (supplied by the Vagus nerve - CX)
true or false: since CXII supples motor innervation to the tongue it also supples palatoglossues
false, it is by vagus
