Cranial Nerves Flashcards
What cranial nerves are associated with the eye and ocular structures?
2,3,4,V1,V2,6,7
What does the afferent pathway do?
Take sensory information away from the organ.
-carry sensory information from cornea,iris,conjunctiva, and sclera
What areas give sensory information to the infratraochlear nerve?
- caruncle
- canaliculi
- lacrimal sac
- medial aspect of eye lid
- skin on side of the nose
How does the infratrochlear nerve run after it enters the orbit?
- it runs under the trochela
- runs along the upper border of the medial rectus then joins nasociliary nerve
What areas give sensory information to the anterior ethmoid nerve?
- skin from the center of the nose
- nasal mucosa
- ethmoid sinuses
What areas give sensory information to the posterior ethmoid nerve?
-ethmoid and sphenoid sinuses
How do the ethmoid nerves run?
–enter the orbit with their arteries then through a foramen within the frontoethmoid suture to join the nasociliary nerve
Where does sensory innervation exist in the cornea? Where does it not exist?
Yes: epithelium, anterior stroma, mid stroma
No: post stroma, Decemets membrane, endothelium
How many long ciliary nerves are there?
- 1 medial and 1 lateral
Describe the path of the long ciliary nerves
- go between sclera and the choroid to the back of the eye
- leave the globe 3mm on each side of the optic nerve
- then join nasocilary nerve
Aside from sensory information, what else do the long ciliary nerves do?
-transmit sympathetic fibers to dilator muscle of the iris
How many short ciliary nerves are there?
Many
Describe the path of the short ciliary nerves
- enter choroid and join choroidal nerves
- go to the back of the eye and leave as 6-10 short ciliary nerves
- exit the sclera as a ring around the optic nerve with the short ciliary arteries
- enter ciliary ganglion
- DO NOT SYNAPSE
- join nasociliary nerve
Name all of the nerves that join/ form the nasociliary nerve
- infratrochlear
- anterior and posterior ethmoid
- long ciliary nerves
- short ciliary nerve (sensory root from ciliary ganglia)
What is the path of the nasociliary nerve after it gets all of its input from the other nerves?
-pass through oculomotor foramen within common tendonous ring and superior orbital fissure to enter cranial cavity
Herpes zoster is associated with what sign? What does that indicate?
- Hutchinson’s sign
- nasociliary nerve is effected through infratrochlear nerve
- if posterior ciliary nerve is effected, the cornea is likely to be effected
What nerves make the frontal nerve?
Supraorbital and Supratrochlear
What areas give information to the supratrochlear nerve?
-skin, muscles of the forehead and upper eyelid
How does the supratrochlear nerve enter the orbit?
Piercing the superiormedial corner of the orbital septum
What is the path of the frontal nerve?
- between levator muscle and the periorbita
- exits orbit through the superior orbital fissure ABOVE the common tendonous ring
What areas give information to the lacrimal nerve?
- lateral aspect of the upper eye lid and temple area
- lacrimal gland
Describe the path of the lacrimal nerve
- runs posteriorly along the upper border of the lateral rectus muscle
- exits orbit through superior orbital fissure above the annulus of Zinn
The lacrimal nerve receives a branch from ________________ which carries autonomic innervation of the lacrimal gland
Zygomatic nerve
Name the nerves that come together and form the ophthalmic division of trigeminal
- frontal
- lacrimal
- nasociliary
What areas give sensory information to the infraorbital nerve?
-cheek, upper lip, lower eye lid
Describe the path of the infraorbital nerve
- enters maxillary bone through infraorbital foramen
- runs posteriorly through infraorbital canal
- exits the orbit by inferior orbital fissure to join maxillary nerve
Sensory fibers from what area make the zygomaticotemporal nerve?
-lateral forehead
Sensory fibers from what area make the zygomaticofacial nerve?
-lateral cheek and lower eyelid
What is the path of the zygomatic nerve?
- go along the lateral wall of the orbit
- exit orbit through inferior orbital fissure and join maxillary nerve
What are the 6 nerves that innervate the eyelid?
- supraorbital
- supratrochlear
- infratrochlear
- lacrimal
- zygomaticofacial
- infraorbital
How does the maxillary nerve enter the skull?
Foramen rotundum
Maxillary nerve receives autonomic fibers from what?
Pterygopalatine ganglion
If the oculomotor nerve is damaged, what other nerve can you expect to be damaged? (Cavernous sinus)
Trochlear
What are the nerves that supply striated muscles of the orbit?
- oculomotor
- trochlear
- abducens
- facial
How does the oculomotor nerve run in the cavernous sinus?
- pierces the roof of the cavernous sinus
- runs within the two dural layers of its lateral wall above the trochlear nerve
How does the superior division of the oculomotor nerve run?
-medially above the optic nerve and enters the superior rectus on its INFERIOR surface
What does the superior division of the oculomotor nerve innervate?
- superior rectus
- levator palpebrae superioris
What do the three branches of the inferior division of the oculomotor nerve innervate?
- Enters medial rectus on lateral surface
- Enters inferior rectus on superior surface
- Gives off parasympathetic fibers to ciliary ganglion then runs along lateral border of the inferior rectus
What does the trochlear nerve innervate?
Superior oblique muscle
How does the trochlear nerve run in the cavernous sinus?
- lies between oculomotor nerve and V1
- gives sensory fibers to V1
How does the trochlear nerve run when it exits the cavernous sinus?
- exits by superior orbital fissure
- above the common tendinous ring and outside the muscle cone
- runs with frontal nerve on medial wall of the orbit above the levator and superior rectus muscle and enters upper surface of superior oblique
Where does the abducens nerve lie in the cavernous sinus?
-near the lateral wall of the internal carotid artery
How does the abducens nerve run?
- enters the orbit through the superior orbital fissure
- within the common tendinous ring
- innervates lateral rectus muscle on medial side
What does the temporal and zygomatic branches of the facial nerve innervate?
-temporal and zygomatic branches supply the frontalis, procerus, corrugator, and orbicularis muscle
What are the two roots of the facial nerve and their functions
- Large motor root for facial muscles
2. Smaller root with sensory and parasympathetic fibers
The sensory fibers of the facial nerve carry information for what area?
Tongue
The parasympathetic nerve of facial nerve innervate what?
-secretorymotor fibers to various glands of face (lacrimal gland)
