lecture 18: 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