cranial nerves Flashcards
What pathway is away from target organ?
Afferent pathway
The fibers of the trigeminal nerve serving the ocular structures are _______ and originate in the innervated structures.
sensory
What is the most important branch of Trigeminal?
V-1 ophthalmic branch
What is the first branch of the ophthalmic nerve?
Nasociliary nerve
Where do sensory fibers come from for the nasociliary nerve?
from medial canthal area
caruncle, canaliculi, lacrimal sac etc
What nerve benetrates the orbital septum, enters the orbit BELOW trochlea and runs along UPPER border of medial rectus and becomes nasociliary?
infratrochlear
what nerves come off of the nasociliary as it runs along the medial aspect of the orbit going into sinuses?
anterior and posterior ethmoidal
Cornea has epithelium, endothelium and _________ membrane. Where is sensory innervation located?
basement first half (most anterior half, epithelium, anterior stroma, and mid stroma) have sensory nerve fibers
Corneal _______ innervation is very dense, estimated to be 400 times as dense as other tissue.
sensory
3 Different tunics of eye?
Connective tissue
Vascular
Fibrous layer
The eye has dual exhaust what does this mean?
there are two long ciliary nerves coming off medial and lateral to join with the nasociliary nerve.
What are the nerves that are more toward the periphery and limbus (white part of eye interface)?
short ciliary nerves
How do ciliary nerves get to back of eye?
they run in vascular tunic (middle layer), to back of eye and go through ciliary ganglion. (because sensory doesn’t need to synapse in autonomic ganglion)
The short ciliary nerves exit the ______ in a ring around the optic nerve.
sclera
Know exits points of all nerves and vasculature on slide 12.
4 vortex veins 2 long ciliary arteries 2 long ciliary nerves many short ciliary arteries many ciliary nerves
The nasociliary nerve exits the orbit by passing through the __________ foramen within the common tendinous ring and the ________________ into the cranial cavity.
oculomotor foramen
superior orbital fissure
Approximately __ of all cases of Herpes Zoster will affect the ophthalmic division of the trigeminal nerve.
10%
The rash on the side of the nose is called what in shingles?
hutchinson’s sign
The ____________ nerve enters the orbit by piercing the superior medial corner of the orbital septum.
supratrochlear nerve
The supraorbital joins the supratrochlear nerve midway in the orbit and forms the ___________.
Frontal nerve
The frontal nerve runs posteriorly between the ________ muscle and the periorbita, exiting the orbit through the superior orbital fissure above the ______________.
levator
common tendinous ring
The ___________ runs posteriorly along the upper border of the lateral rectus muscle.
Lacrimal nerve
The lacrimal nerve exits the orbit through the _____________.
superior orbital fissure
What 3 nerves join and form the ophthalmic division of the trigeminal nerve?
Nasociliary- medial (above medial rectus)
frontal- superior (above levator)
lacrimal- lateral (above lateral rectus)
The ophthalmic nerve enters the ______ wall of the cavernous sinus.
lateral
The __________ nerve is formed by sensory fibers from the cheek, upper lip, and lower eyelid.
infraorbital nerve
When infraorbital nerve is in the maxillary bone it is joined by 2 nerves from what structures?
upper teeth and maxillary sinus
The infraorbital nerve leaves the orbit through the ___________ and joins with the __________.
inferior orbital fissure
maxillary nerve
Maxillary nerve enters skull through the__________.
Foramen rotundum
The maxillary nerve traverses the area between the maxilla and the ________ bone.
sphenoid
The motor cranial nerves that supply striated muscles of the orbit are the _________, _________, the _________, and the __________.
Oculomotor
trochlear
abducens
facial
The oculomotor pierces the ____ of the cavernous sinus and runs along the lateral wall above the _______ nerve.
roof
trochlear
The oculomotor exits the cavernous sinus and enters the orbit through the ____________.
superior orbital fissure
The superior branch of CN3 runs medially above the optic nerve and enters the _____________ on its inferior surface.
superior rectus
The inferior branch of CN3 runs anteriorly and branches into 3 branches. What are they and how do they run?
Enters medial rectus on lateral surface
Enters inferior rectus on upper surface
Parasympathetic fibers extending to ciliary ganglion
Is trochlear inside or outside of annulus of ZInn?
outside
The trochlear nerve runs with the ___________ to the medial side of the orbit above the levator and superior rectus, and enters the upper surface of the superior oblique.
frontal nerve
This nerve is within the cavernous sinus and lies near the lateral wall of the internal carotid.
Abducens
The abducens enters orbit through the superior orbital fissure within the common tendinous ring and goes into the _________ surface of the _________.
medial surface
lateral rectus
The _________ nerve has 2 roots, large motor root innervates the facial muscles and the smaller root contains sensory and parasympathetic fibers.
facial
