Term
Do tears or aqueous have a greater concentration of glucose to supply the cornea? |
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Definition
| The concentration of glucose in the aqueous humor is much higher and supplies the cornea. |
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Term
| Is the aqueous the main supply of oxygen to the corneal epithelium? |
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Definition
| No, the air is. When you're asleep oxygen diffuses from the palpebral conjunctiva. |
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Term
| If you lose epithelial innervation does corneal metabolism still occur at its proper level? |
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Definition
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Term
| What supplies oxygen to the corneal endothelium? |
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Definition
the aqueous in the anterior chamber |
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Term
| Why is the Kreb's cycle less active in the superficial epithelium? |
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Definition
| there are fewer organelles, including mitochondria in these cells |
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Term
| The hexose monophosphate shunt (same as pentose phosphate shunt) generates the NADP necessary for the synthesis of what type of amino acids? |
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Definition
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Term
| Can lactic acid pass through the epithelium? |
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Definition
| No, it has to move posteriorly and in the process it draws in water overriding the pump mechanism causing corneal stromal swelling and creates metabolic acidosis. DNA synthesis declines in the basal epithelial layer and mitosis stops within 8 hours. |
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Term
| How low can the partial pressure of oxygen get before the corneal epithelium starts to swell? |
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Definition
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Term
| How long does it take the cornea to heal if the basement membrane is not damaged? What if it is damaged? |
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Definition
| If the basement membrane is damaged corneal healing only takes a couple days, but if the basement membrane is damaged, corneal wound healing can take up to several weeks. |
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Term
| Will Bowman's layer regenerate if it is damaged? |
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Definition
| No, it will be replaced either by stroma like fibrous tissue or by epithelium. |
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Term
| What is one potential side effect of Beta blockers on the cornea? |
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Definition
| Beta blockers effect the sympathetic nerves and can lead to neurotrophic keratitis |
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Term
| Why is Calcium added to some irrigating solutions? |
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Definition
| To help maintain the junctional complexes and hence uphold the Transepithelial potential in the cornea. |
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Term
| Does treating a glaucoma patient with a Carbonic Anhydrase Inhibitor effect corneal hydration? |
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Definition
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Term
| What type of corneal dystrophy reduces corneal transparency by the accumulation of amyloids in the stroma? |
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Definition
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Term
| What type of corneal dystrophy decreases corneal transparency by abnormal keratan sulfate synthesis? |
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Definition
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Term
| What type of corneal dystrophy reduces corneal transparency by the presence of microfibrillar desposits? |
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Definition
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Term
| Why is Fuch's dystrophy, a disorder of the endothelial metabolic pump, worse in the morning than later in the day? |
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Definition
| lack of evaporation of the tears at night hence an increase in corneal swelling |
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Term
| What is corneal thinning that results from localized areas of of corneal drying? |
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Definition
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Term
| How does the IOP have to get to cause corneal swelling? |
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Definition
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