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Where does the conjunctiva extend from?
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Limbus through the fornices into the eyelids. Palpebral conjunctiva: lines the eyelidsBulbar conjunctiva: lines the eyeballFoniceal conjunctiva: lines the fornices.
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What are the two layers of the bulbar conjunctiva?
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1. Stratified epithelial layer: continuous with the corneal epithelium. Superficial cells have microvilli and goblet cells and their cytoplasm contains melanin granules2. Submucosa: CT stromal layer, like the corneal stroma.
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Plica Semilunaris:
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Conjunctival fold at the medial canthus that contains smooth muscle, goblet cells and adipose tissue to reduce stretching of conjunctiva on lateral eye movements. Provides slack in the conj. for lateral movement.
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Caruncle:
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Hill of tisssue located on the medial side of the plica semilunaris. unknown function. Contains goblet cells, hair follicles, and sebaceous and sweat glands. Likely source for the collection of debris and gunk that is present when you wake up in the morning.
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Conjunctiva blood supply:
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Palpebral and forniceal portions are supplied by the peripheral arcades. The bulbar conj is supplied by the anterior ciliary arteries.
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Conjunctival sensory innervation:
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Bulbar conjunctiva: Innervated by the long posterior ciliary nervesPalpebral conjunctiva: V1 and V2
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Lens: location?
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Between the iris and the vitreous
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What are the three main parts of the lens?
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The lens capsule, the lens epithelium, and the lens fibers. Lens capsule is outermost, lens fibers = bulk of the interior of the lens
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Where are anterior subcapsular cataracts located?
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Directly under the lens capsule
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Where are posterior subcapsular cataracts located?
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Just in front of the posterior capsule. PSC's often affect near vision more than distance vision and are commonly a result of systemic steroid use.
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What are PSC's a common result of?
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systemic steroid use.
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What are the most common aging cataracts?
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Nuclear: commonly introduce myopic shifts.
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What layers of the lens do cortical cataracts affect?
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Anterior, equatorial and posterior cortex layers. The present as spoke-like projections
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Where is the lens capsule thickest?
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At the anterior midperipheral portion of the lens.
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Where is the lens capsule the thinnest?
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At the posterior pole.
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