Term
| What is the only joint in the skull that is movable? |
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Definition
| The temporomandibular joint |
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Term
| What are the two main vessels that supply the orbit and surrounding structures? How many branches does each have? |
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Definition
External Carotid (3 branches: anterior temporal, maxillay, facial)
Internal Carotid aka ophthalmic (9 branches: CRA,lacrimal, ethmoidal, muscular, supraorbital, posterior ciliary, medial palpebral, supratrochlear, dorsonasal) |
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Term
| What branches of the ophthalmic artery anastomose with branches of the external carotid? |
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Definition
Supraorbital and Supratrochlear (w/anterior temporal artery)
Dorsonasal (w/infraorbital and transverse facial)
Recurrent meningeal (w/middle meningeal)
p.208 Remington |
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Term
| The muscular artery has two branches. If the lateral muscular artery was blocked by an embolus, which muscle would lose their blood supply? |
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Definition
medial rectus, inferior rectus, inferior oblique
Remember SMILE (sup-med, inf-lat) |
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Term
| Why is CN VI most likely affected by an ICA aneurysm? |
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Definition
| It travels side-by-side with it through the cavernous sinus. |
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Term
| What vascular structures can a cilioretinal artery originate from? |
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Definition
| The choroid of the Circle of Zinn |
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Term
| What is the shortest branch of the ophthalmic artery? |
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Definition
| The central retinal artery |
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Term
| The Vascular Circle of Zinn can be divided into a superior and inferior portion based on where medial and lateral SPCA's enter. This area is often affected during an AION. Based on this anatomical info, what type of defect would you expect? |
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Definition
Altitudinal
P.S. The inferior field is more often lost than superior |
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Term
| Which arteries supplies more anterior structures short or long posterior ciliary arteries? |
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Definition
Long posterior cil: supply anterior choroid and MACI
P.S. Short supplies choroid, ONH, macula |
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Term
| The muscular arteries supply the EOMs. The muscular arteries supplying the recti are known as the anterior ciliary artery. Most recti have 2 of these. Which is the only rectus that has only 1 ACA? |
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Definition
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Term
| How are the veins similar to those found in the rest of the brain? |
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Definition
| They lack valves (bad news if an infection gets back there!) |
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Term
| Name the veins that drain the inner retina, iris, and choroid respectively. |
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Definition
CRV
Anterior ciliary veins (also drains CB, Schlemm's canal, Conj)
Vortex Veins |
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Term
| Where is an alternative drainage site besides the cavernous sinus? |
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Definition
Pterygoid venous plexus
the inferior ophthalmic vein may also drain here
the infraorbital vein drains here |
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Term
| What cranial nerves travel through the cavernous sinus? |
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Definition
3,4, 6, V1, V2
Remember, V3 and 7 do not go through... |
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Term
| What 5 things determine the refractive power of the cornea? |
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Definition
1) the radius of curvature of ant cornea
2) change in ref index from air to cornea
3) corneal thickness
4) radius of curvature of posterior cornea
5) change in refractive index from cornea to aq humor |
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Term
| What are the two jobs of the cornea? |
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Definition
| Refract and transmit light |
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Term
| What is the physiological optical property called that allows the corneal stroma to minimize light scatter? |
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Definition
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Term
| What in the corneal epithelium adjoins the mucin layer of the tear film? |
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Definition
The glycocalyx
Which is secreted by the plasma membrane? |
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Term
| What layer of the cornea does not continue past the limbus (i.e. corneal epithelium becomes conj epithelium)? |
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Definition
| Bowmann's membrane has no counterpart in conj or sclera |
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Term
| What in the cornea connects cells to a basement membrane? |
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Definition
hemidesmosomes
P.S. Take 8 weeks to regenerate (why patients on muro128 for 2 mos w/RCE) |
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Term
| What type of collagen is in Bowmann's? Descmet's? |
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Definition
Type 1--Bowmann's
Type 4--Descmet's |
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Term
| True or false: keratocytes in the stroma are randomly arranged. |
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Definition
False. To maintain transparency, the stroma can't be irregularly arranged.
Keratocytes have a higher conc. in the anterior stroma and form a corkscrew pattern. |
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Term
| What makes up the GAG's in the corneal stroma? |
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Definition
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Term
| What is the difference between Hassal-Henle bodies and guttata? |
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Definition
| Location. Both are thickened bulges of Descmet's, but guttata are central and Hassal-Henle are peripheral |
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Term
| True or false: corneal endothelial mitochondria increase in number with age. |
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Definition
| False, they decrease in number with age. |
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Term
| Descmet's membrane actually has an anterior and posterior portion. Which of these is produced throughout life, and therefore responsible for thickening of this layer? |
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Definition
Posterior.
The anterior portion is formed embryonically. |
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Term
| What are the three sources of nutrients for the cornea? |
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Definition
Aq humor
Limbal conj and episcleral capillaries
Palpebral conj networks |
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Term
| In what corneal layer do nerves lose their myelin sheath? |
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Definition
Bowmann's
But they enter the cornea midstroma so are absent in endothelium and Descmet's |
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Term
| Which upper lid muscle branches off the levator palpebrae superioris? |
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Definition
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Term
| Name the 4 functions of the eyelid. |
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Definition
Protection (covers globe)
Move tears toward medial canthus to drain
Spread tear film over eye upon opening
Contains structures that produce tear film |
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Term
| Where do the upper and lower eyelids join? |
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Definition
| The medial and lateral canthi |
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Term
| How often are cilia (eyelashes) replaced? |
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Definition
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Term
| Which muscle is responsible for opening eyelid? What nerve innervates this muscle? Same question for closing the lid. |
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Definition
Levator palpebrae superioris (CN III) opens; Mueller's also maintains it being open
Orbicularis oculi (CN VII) closes |
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Term
| What is the name of the structure that covers both the lacrimal gland and the lacrimal sac? |
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Definition
| The periorbita (orbital fascia) |
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Term
| If a patient comes in with a blow-out fracture, what structure suspends the globe? |
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Definition
| The suspensory ligament of Lockwood |
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Term
| Is the tarsal plate for the superior or inferior lid larger? |
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Definition
Superior lid is larger, 11mm
Inferior lid is smaller, 5mm |
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Term
| What are the mechanisms of secretion for each of the glands of the eyelid? |
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Definition
Meibomian--holocrine
Zeiss--holocrine
Moll--apocrine
Krause & Wolfring--merocrine |
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Term
| The accessory lacrimal glands (Krause & Wolfring) contribute to maintenance tearing. What layer of the tear film do they contribute to? |
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Definition
The aqueous layer
Which makes up 90% of the tear film |
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Term
What are the anti-bacterial components found in tears?
What immune components are found in the submucosa of the palpebral conj? |
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Definition
Tears--lysozyme, IgA
Palpebral conj- IgA, macrophages, mast cells, PMN's, eosinophils |
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Term
| What is the main vessel that supplies blood to eyelids? |
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Definition
| Internal carotid (ophthalmic) |
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Term
| What is the first hair produced during embryological development? |
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Definition
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Term
| Which muscle compensates for ptosis? |
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Definition
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Term
| Only 75% of the tears pass through the lacrimal drainage system. Where do the others go? |
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Definition
| They are lost via evaporation or reabsorbed by the conj |
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Term
| Explain what happens to each structure in the lacrimal drainage system when they eyelids close. When they open? |
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Definition
Eyelids closed: tears pool into lacrimal lake and excess drains into puncta--> canaliculus shortens--> lac sac expands and fills w/tears
Eyelid opens: puncta initially occluded--> canaliculus lengthens and siphons in tears--> lac sac collapses and pushes tears into NLD (valve of Hasner prevents backflow) |
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Term
| What is located in the orbit? |
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Definition
| globe, EOMs, orbital blood vessels, connective tissue |
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Term
| Which EOM is the only one with anterior insertion to the globe? |
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Definition
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Term
| What is the name of the procedure that measures the function of V1? Where on the skull would you fix the electrodes? |
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Definition
Visual Evoked Response (VER)
Fixate electrodes on external occipital protruberance (inion) |
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Term
| Where does the facial nerve exit the skull? |
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Definition
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Term
| Name the bones of the face. |
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Definition
| Frontal, maxillary, nasal, vomer, lacrimal, palatine, zygomatic, mandible |
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Term
| Is the orbit larger horizontally or vertically? |
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Definition
Horizontally (4cm)
Vertically, it is 3.5cm |
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Term
| In what bone is the carotid canal located? |
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Definition
| Temporal bone (petrous portion) |
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Term
| What passes through the trochlea? |
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Definition
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Term
| What is the importance of Whitnall's tubercle? |
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Definition
| The attachment site for the aponeurosis of the superior levator, lateral palpebral and lateral check ligaments |
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