Term
The lacrimal gland secretes what three things? |
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Definition
Water, electrolytes, and proteins |
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Term
The lacrimal gland is part of a functional unit that includes the cornea and conj, accessory lacrimal glands, and meibomian glands that serves to do what? |
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Definition
Maintain the tear film homeostasis and meet tear fluid demand via neural and hormonal feedback loops |
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Term
Which lacrimal gland is primarily responsible for normal or basal aqueous secretions? Which is responsible for reflex secretion? |
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Definition
Primary lacrimal gland The accessory lacrimal glands |
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Term
Normal aqueous secretion is about 1.2 microliters/min. What happens to the secretion rate with reflex stimulation? |
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Definition
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Term
The aqueous layer of the tear film is renewed how often? |
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Definition
Every 6-7 mins All production is probably neurogenic/reflex stimulation |
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Term
Does aqueous production decline or increase with age? Which of the sexes has less production after age 30? |
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Definition
Decline (50% by age 65) Females |
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Term
Does the basal aqueous production vary during the day? When does basal aqueous secretion shut off? |
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Definition
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Term
What is the most common cause of reflex aqueous secretion? |
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Definition
Stimulation of CN V -cornea and conj: foreign body, trauma, enviornment -nasal mucosa |
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Term
Can emotion or pain cause a stimulus to secrete aqueous? |
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Definition
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Term
Are the accessory lacrimal glands (Krauss and Wolfring) responsible for a large amount of total aqueous secretion? |
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Definition
NO - Literature varies but around less than 10% |
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Term
Structurally and functionally, the lacrimal gland is what type of gland? |
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Definition
Tubuloacinar exocrine gland |
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Term
The palpebral lobe of the lacrimal gland is located where? Orbital lobe? |
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Definition
Palpebral lobe is located in the superolateral fornix and can be seen with lid eversion Orbital lobe is located against the frontal bone in the lacrimal fossa |
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Term
The lacrimal gland and its acini converge to empty its contents into 12 ducts that open to where? |
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Definition
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Term
What cells lie next to the basal surface of the acini and may act as a pump and also contain contractile protein? |
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Definition
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Term
The electrolyte secretions of the lacrimal gland are driven by what? |
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Definition
Na+K+ATPase pump - sets up an electrochemical gradient |
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Term
Secretory fluid of acini is similar to what? |
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Definition
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Term
The movement of water into the lumen is consequence of ion movement. How does water physically enter the lumen? |
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Definition
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Term
The majority of protein secreted by the lacrimal gland is regulated by neurotransmitters and neuropetides in what process? What other way is protein secreted? |
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Definition
Exocytosis
Intrinsic or constitutive synthesis/secretion - Made and released immed. |
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Term
Lacrimal gland protein secretion can also be autonomically regulated via the parasympathetic and sympathetic portion of the reflex arc. The secretory vesicles are stored and releaed upon stimulation of what pathways? |
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Definition
G=protein or CAMP mediated pathways |
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Term
Hypertonic tears result from what? Hypotonic tears result from what? |
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Definition
Decreased stimulation and/or evaporation Increased stimulation (more fluid and less dissolved protein) |
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Term
What is the largest protein present in tears? |
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Definition
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Term
Lactoferrin is a tear specific pre-albumin protein. What is main function? |
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Definition
It is bacteriostatic, possibly bacteriolytic. It binds to iron ions, which are essential for bacterial metabolism. |
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Term
Lysozyme is a protein that is considered what? What does it dissolve? |
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Definition
Bacteriolytic It dissolves gram positive cell walls |
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Term
Proteins like epidemalGF, transformingGF, hepatocyteGF, and keratinocyteGF do what to the corneal epithelium? |
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Definition
Have a role in healing, proliferation, and migration of epithelium |
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Term
What protein acts on the cell membrane? |
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Definition
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Term
What protein is an enzyme in high concentration that comes from corneal epithelium and corneal metabolism? |
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Definition
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Term
What immunoglobulin provides antibody defense in the eye versus infectious agents? Who would have lower amounts of this immunoglobulin? |
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Definition
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Term
What are the primary and secondary defense steps taken by IgA against infectious agents? |
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Definition
Primary - Prevent adhesion of microorganisms to ocular surface Secondary - Induce phagocytosis by PMN's (neutrophils) |
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Term
The tears are 98.2% what? |
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Definition
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Term
Evidence in morphology and function reveal that which sexes acini are larger? |
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Definition
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Term
Androgens have been shown to have an anti-inflammatory role as well as a cell maintenance role in the lacrimal gland. When do these androgens decrease? What treatment is Dr Connor working on? |
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Definition
During menopause Treating dry eye with testosterone cream |
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Term
Prolactin is a peptide hormone that is synthesized in what cells of the lacrimal gland? |
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Definition
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Term
The prolactin receptors in the acinar cells of the lacrimal gland serve to do what? |
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Definition
Modulate cell activity and immune function of the gland Moderate fluid balance, cell growth, and differentiation |
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Term
What is an osmole? What is the difference between osmolarity and osmolality? |
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Definition
An osmole is the amount of substance that dissociates in solution to form 1 mole of osmotically active substance.
Osmolarity = osmols/L Osmolality = osmols/kg The two can be used interchangebly because at std pressure and std temp they are the same |
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Term
The normal osmolality of tears is 304-318 mosm/L. Does the osmolality of tears increase or decrease with contact lens wear? |
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Definition
It decreases in contact lens wearers initially and then increases back to normal with adaptation. |
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Term
Dry eye syndrome (DES) is a condtion of increased tear osmolarity due to what two factors? |
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Definition
Evaporation and reduced aqueous production |
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Term
According to J Gilbard, MD, what are the four milestones of Dry-Eye Disease? |
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Definition
Increased tear osmolarity Decreased goblet cell density and decreased corneal glycogen Corneal desquamation Decreased surface glycoproteins |
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Term
Severe dry eye is called what? |
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Definition
Keratoconjunctivitis sicca (KCS) |
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Term
What is the systemic autoimmune disease that pathologically destroys all the bodies moisture producing glands? |
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Definition
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Term
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Definition
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Term
Can dry eye be an inflammatory condtion? |
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Definition
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Term
The pH of aqueous secretion is about 7.4 with a comfort range from 7.3 to 7.7. If the pH lowers below 6.6 or rises above 7.8, what can happen to the patient? |
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Definition
Discomfort and increased lacrimation |
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Term
Injuries tend to _____ alkalinity of the aqueous and bacterial infection seems to do what? |
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Definition
Increase Infection causes the pH to lower to 5.2 because of the acidic by-products of bacteria |
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Term
Which buffer is responsible for keeping the pH of the aqueous secretions close to 7.4? |
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Definition
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Term
In the morning, what is the pH of the aqueous secretions? |
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Definition
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Term
The temperature of the cornea surface is 35 degrees - 36 degrees Celsius. Does it increase or decrease with lid closure? With CL wear? |
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Definition
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Term
At what temperature does all metabolism of corneal epithelium cease? |
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Definition
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Term
In general, do anti-histamines and anti-depression drugs increase or decrease tear production? What about marijuana or pilocarpine? |
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Definition
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