Term
| What lies at the apex of the orbit of the eye (remember that the orbit is shaped like a pyramid so the apex is deep)? |
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Definition
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Term
| What passes through the optic foramen? |
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Definition
| optic nerve and ophthalmic artery |
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Term
| What area of the orbit is very thin and prone to blowout fractures and infections? Just how thin is it? |
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Definition
Medial Wall (area over the ethmoid bone, ethmoid air cells)
0.2-0.4 mm thick |
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Term
| 4 nerves pass through the superior orbital fissue. Name them. |
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Definition
There all in a neat little row for you. 3, 4, 5, and 6 more specifically:
III - occulomotor
IV - trochlear
V-1 - opthalmic branch of trigeminal
VI - Abducens |
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Term
| What is the special property to remember about the optic nerve that has implications for CNS effects if anesthetic is injected too close to this nerve? |
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Definition
| It is actually an extension of the brain and is therefore covered by the meninges (arachnoid, dura, and pia mater). If you inject into this nerve sheath the agent can go back to the midbrain via the CSF and produce CNS effects. |
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Term
| Gayle has a slide showing the central retinal artery and vein and doesn't say too much about it except that it travels with the optic nerve. Because I'm not sure exactly what she's trying to get across, can you tell me what artery the CRA is a branch of? |
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Definition
The central retinal artery (retinal artery) branches off the ophthalmic artery, running inferior to the optic nerve within its dural sheath to the eyeball.
It pierces the optic nerve close to the eyeball, sending branches over the internal surface of the retina, and these terminal branches are the only blood supply to the larger part of it. |
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Term
| What cranial nerve, pertaining to the eye, sends parasympathetic innervation to the ciliary ganglion? |
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Definition
Occulomotor
(I use the pneumonic VFOG to remember all the cranial nerves that send out parasympathetic fibers. Vagus, Facial, Occulomotor, glossopharyngeal.) |
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Term
| T or F: The ciliary ganglion recieves sympathetic and parasympathetic innervation from the occulomotor nerve. |
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Definition
| False. Recieves para from CN III but sympathetic innervation comes from the carotid artery plexus (which is derived from the superior cervical ganglion). |
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Term
| T or F: Sympathetic nerve firing causes the iris to contract/constrict, thus causing miosis. |
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Definition
| False, the pupils contract causing MYDRIASIS. (There's a "Y" in mydriasis and a "Y" is sympathetic) |
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Term
| You should know whether each cranial nerve is sensory, motor, or both. So tell me what the 4 nerves that pass thru the superior orbital fissure are and whether they are sensory, motor, or both. |
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Definition
Make you chart with Dr. Ts pneumonic "Old Opie Opened The Trunk And Found Very Green Vestiges And Hemp" and line it up with his other pneumonic "Some Say Money Matters But My Brother Says Big Brains Matter Most" and you should come up with:
CN III - occulomotor - motor
CN IV - Trochlear - motor
CN V(1) - Trigeminal (ophthalmic) - Both
CN VI - Abducens - Motor |
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Term
| What nerve provides pain, touch and temperature sensation to the cornea, iris, lacrimal gland, conjunctiva, nasal mucosa, eyelid, eyebrow, forehead and nose? |
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Definition
| Opthalmic division of the trigeminal nerve. |
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Term
| T or F: The superior oblique muscle moves the eye in and down (intorsion/depression)? |
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Definition
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Term
| What occular condition in kids might make you want to do a TIVA? How would you recognize this condition? |
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Definition
| Strabismus. You're patient would probably have googley eyes (improper alignment - lack of coordination between ocular muscles). You can sort of diagnose it by covering up the straight eye. If you cover their straight eye and the googley moves in to focus on an object then you've probably got strab. The straight eye doesn't correct itself if the googley is covered because it's already in focus. |
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Term
| In what direction(s) does the inferior oblique move the eye? What innervates it? |
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Definition
| Out and Up (Extorsion/Elevation). CN III |
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Term
| In what direction does the lateral rectus move the eye? Innervation? |
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Definition
| Outward (abduction). CN VI. |
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Term
| T or F: the medial rectus is innervated by CN III and moves the eye medially (toward the nose - adduction). |
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Definition
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Term
| Innervation of the superior oblique muscle? |
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Definition
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Term
| T or F: the superior rectus muscle causes supraduction of the eye. |
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Definition
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Term
| T or F: the inferior rectus causes infraduction of the eye and is innervated by CN III. |
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Definition
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