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Ocular Physiology 1.3
starts at Pupil and Iris
49
Other
Not Applicable
09/30/2007

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Cards

Term
Where would a lesion be located in the case of Adie's pupil?
Definition
ciliary ganglion
Term
Is the near response of a pupil supposed to be greater than the light response?
Definition
No, this is abnormal. The near resonse is less than the light response.
Term
What is the supranuclear origin of the light reflex?
Definition
Pretectal nucleus
Term
What is the supranuclear origin of the near reflex?
Definition
Cortical areas surrounding the visual cortex and cortical areas within frontal eye fields
Term
What is the motor center for convergence?
Definition
oculomotor subnuclei for MR
Term
What is the motor center for accommodation?
Definition
anteromedial portion of the Oculomotor nucleus
Term
What is the motor center for miosis?
Definition
small celled columns in the E-W area of oculomotor group
Term
What is the largest layer of the tear film?
Definition
aqueous layer>mucous layer>lipid layer
Term
How do contact lenses cause dry eye?
Definition
They disrupt the glycocalyx on the corneal epithelium that interacts with mucin layer of the tear film which is used to stabilize the tear film.
Term
Which two layers of the tear film are thought to be dissolved into one?
Definition
aqueous and mucin layer
Term
What is the name for a heterogenous collection of high molecular weight glycoproteins?
Definition
mucin
Term
Do both the mucin and the corneal epithelium possess carbohydrate side chains?
Definition
Yes, their interaction provides stability to the tear film
Term
What does dissolved mucin do to the surface tension of tears?
Definition
It lowers it. Wetting angle is 81 degree without dissolved mucin, but only 20 degrees with dissolved mucin
Term
What type of mucin is secreted by conjunctival goblet cells?
Definition
MUC5AC
Term
What type of Mcuin is synthesized by the stratified conjunctival epithelium?
Definition
MUC4
Term
What type of mucin is synthesized by the cornea and conjunctival epithelium?
Definition
MUC1
Term
What molecular event is necessary to refresh the tear film at each blink?
Definition
Detachment at the glycocalyx
Term
What causes sleepers?
Definition
mucin trapped by the caruncle cilia
Term
Do tears have mucin degrading enzymes?
Definition
probably not
Term
What cellular organ releases the protein portion of the mucin?
Definition
ER
Term
What cellular structure forms the sugar portion of mucin?
Definition
Golgi apparatus
Term
What receptor agonist mediates mucosal surface lubrication and also increases Cl- secretion?
Definition
P2Y2 receptor
Term
What mucus peptide interacts with mucus to effect the rheology of mucus, influences migration rates in healing?
Definition
TFF peptides
Term
What cells form the thin inner glycocalyx of the mucin layer?
Definition
MUC1 of the corneal and MUC4 of the conjunctival epithelium
Term
What do Vitamin A deficiency, ocular pemphigoid, Steven's Johnson syndrome, Alkali burn, and hypertonics have in common?
Definition
They can pathologically destroy the goblet cells.
Term
Destruction of which layer of the tear film leads to an increase in TBUT and dry eye?
Definition
lipid layer
Term
Which model of tear film drainage says that siphoning of the lacrimal sac occurs during relaxation of the blink?
Definition
Doanes, Jones theory states that siphoning occurs during contraction of the blink
Term
What enzyme disrupts the polar lipids causing blepharitis? It's secreted by inflammatory cells. It induces the release of the inflammatory mediators, histamine, serotonin, and prostaglandins.
Definition
Phospholipidase (PA2)
Term
What antibiotic can be used to help increase the flow of the Meibomian glands if they're clogged?
Definition
Doxycycline
Term
What inducible protein secreted by the lacrimal gland influences surface tension of the tear film by binding to lipids?
Definition
lipocalin
Term
What is the most common cause of reflex secretion?
Definition
Stimulus to CN V
Term
Which cells lie next to the basal portion of the acini of the lacrimal gland and may act as a pump? They act like smooth muscle fibers.
Definition
Myoepithelial cells, the same cell type as in the dilator muscle of the iris
Term
Which electrolyte is much lower in concentration than in the serum?
Definition
Ca++

K+, Cl- are greater than the serum

HCO3 and Mg+ are equal to the serum
Term
How does water enter the lumen in fluid secretion?
Definition
aquaporins
Term
In fluid secretion water movement is a consequence of what type of movement?
Definition
Ion movement
Term
What is the secretory fluid of the acini similar to?
Definition
plasma
Term
Which type of protein secretion in the lacrimal gland involves the secretion of stored vesicles by exocytosis and is also the most common type of secretion?
Definition
Regulated
Term
What type of protein secretion in the lacrimal gland involves immediate secretion upon synthesis?
Definition
Intrinsic or constitutive
Term
Which type of protein secretion increases with increased tear production?
Definition
Regulated
Term
What tear protein is bacteriostatic (maybe bacteriolytic), by binding with Fe+ ions essential to bacterial metabolism?
Definition
lactoferrin
Term
What enzyme is in the highest concentration in the corneal epithelium?
Definition
lactate dehydrogenase
Term
Name one constitutive protein of the tear film? It is decreased in contact lens wearers.
Definition
IgA
Term
Does the cornea get most of its glucose from the tear film?
Definition
No, Glucose is less than 10% the serum concentration.
Term
Which neurotransmitter works by a G-protein/CAMP pathway?
Definition
Vasoactive intestinal protein (VIP)

Acetylcholine works by a G protein/phospholipidase pathway
Term
Which sympathetic receptor works by a protein kinase pathway to secretion?
Definition
alpha 1
Term
Which sympathetic protein receptor works by a G protein/cAMP pathway?
Definition
Beta receptor
Term
Where are the parasympathetic receptors of the lacrimal gland?
Definition
basolateral cell membrane

Acetylcholine and VIP
Term
Lesions to which division of the nervous system modulate tear secretion in the lacrimal gland by inhibited blood flow through the gland?
Definition
sympathetic system
Term
What is the hormone that binds to the acinar cells and modulates cell activity and immune function in the lacrimal gland? It also moderates fluid balance, cell growth and cell differentiation?
Definition
Prolacin
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