LACRIMAL SYSTEM CONJUNCTIVA Flashcards
What is the main primary provider of the aqueous secretory component to the tear film
main lacrimal gland
What is the lacrimal gland divided by
the lateral horn of the levator and extension of Mueller’s muscle
What two lobes are the lacrimal gland divided into and describe their location
orbital lobe above; palpebral lobe below
T/F Palpebral lobe is the larger of the two lobes and lies behind the orbital septum and above the levator aponeurosis
F; it is the orbital lobe
What is the appearance of the lacrimal gland
pinkish gray
The main lacrimal gland is surrounded by _____ tissue
connective
The main lacrimal gland is made up of many ____ that drain into progressively larger ______
acini; tubules
Acini are ______ ______ cell layer with inner ______ ______ cells
basal myoepithelial; columnar secretory
What is the acini required in order to allow the contents to be drained
muscle movement
Lacrimal gland starts developing near _____ month of fetal life, not functional until ____ birth
third; after
T/F new born babies do not produce tears until 1 week after birth
F; it is 2 weeks, could maybe as long as 2 months
T/F accessory lacrimal gland are the primary provider aqueous secretory component to the tear film
F; it is the secondary provider
What are the 2 accessory lacrimal glands
Krause and Wolfring
Where is the gland of Wolfring located
tarsal plate of the eyelid
T/F more accessory glands are present in the upper eyelid compared to the lower eyelid
T
Historical perspective for the accessory lacrimal gland is _____ and _____ tearing
basal; reflex
What type of secretion is formed by the Wolfring and Krause and what portion of the trigeminal tears is it
serous; middle
Where is the gland of Krause located
conjunctival fornix
T/F the conjunctival fornix is only located on the upper portion of the globe
F; it is located all around the globe
T/F The gland of Krause has a small contribution compared to that of the lacrimal gland
T
Name the three arterial supplies to the lacrimal gland
- lacrimal branch of the ophthalmic artery
- branch of infraorbital artery
- recurrent meningeal artery
What cranial nerve carry sensory stimuli to the lacrimal gland
trigeminal nerve CN 5
T/F Anything that affects the cornea will also affect the lacrimal gland
T
Tear film covers ____ and _____
cornea and conjunctiva
Cornea and conjunctiva also make up the ______ surface
ocular
name the three layers of tear film
- outer lipid layer (meibomian gland)
- middle aqueous layer (lacrimal gland and accessory)
- inner mucous layer (goblet cells in conjunctiva)
What is the primary source of oxygen to cornea
Tear film; because cornea is avascular
Tear film have several functions that are essential to the ______, _______ and ________ of the ocular surface
health; maintenance; protection
Tears contain many ______ proteins that protect the _____ and _____ from the infection
antibacterial; cornea; conjunctiva
Name the 4 functions of tear film
- primary source of oxygen to the cornea
- lubricant between the lids and ocular surface
- movement of tears helps remove foreign bodies debris and exfoliated cells
- tears contain many antibacterial proteins that protect cornea and conjunctiva
What is glands make up the lipid layer of tear film
tarsal gland and sebaceous gland (gland of Zeiss)
What are glands of zeiss
modified sebaceous glands that secrete sebum into the hair follicle of cilia
What glands make up the aqueous layer of tear film
Lacrimal gland, fornix accessory lacrimal gland (glands of Krause), palpebral accessory lacrimal gland (Wolfring)
What cells/glands make up the mucus layer of tear film
goblet cells, epithelial cells and lacrimal gland (very little)
Which of the three layers is the thickest from the tear film
aqueous layer (7 microns)
Which of the three layers is the smallest of the tear film
mucus (.02-.05 microns)
Lipid layer is approximately \_\_\_\_\_ microns A) 0.1 B) 0.11 C) 0.12 D) 0.5
0.1
T/F Lacrimal gland secretion is sero-mucous but mainly serous
T
T/F accessory lacrimal gland secretion is different then the lacrimal gland
F; secretion is identical
What is another name for the palpebral accessory lacrimal gland
Wolfring
What is another name for the fornix accessory lacrimal gland
Krause
There are ____ to ______ meibomian glands in the upper lid
30; 40
There are _____ to ____ meibomian gland in the lower lid
20; 30
Meibomian gland secretes _______
sebum (oily portion of tears)
Conjunctival glands are ______, ______ cells
unicellular; goblet
What 8 types of lipids are included in lipid layer of tear film
- wax monoesters
- sterol esters
- hydrocarbons
- triglycerides
- diglycerides
- free sterols (including cholesterol)
- free fatty acids
- polar lipids (including phospholipids
In what manner are the lipids from the meibomian glands secreted
Holocrine secretion (releasing a secretion that is a product of lysed cell)
What releases the meibomian material from the ducts onto the tear film
a blink
T/F regulation of meibomian secretion is known in great detail
F; not known in great detail
What are two possible steps that regulate meibomian secretion
- controlling the rate of lipid synthesis in ER
2. regulating the rupture of aveolar cells
What will affect lipid synthesis in the ER or the rupture of aveolar cells
Neurotransmitter (nerves surrounding the acini) and androgen sex steroids
What two neural peptides regulate the meibomian glands secretion and are found in what type of nerves
vasoactive intestinal peptide (VIP), neuropeptide (NPY)
Parasympathetic
T/F Testosterone has been found to help regulate synthesis and secretion of meibomian glands
T; but men will not benefit from it
What are the 2 levels of tear secretion and describe when they happen
- low order secretion during normal activities;
2. high order secretion during reflex tearing (crying,etc.)
What is the predominant cell type in the lacrimal gland
acinar cells
The secretion mixture of the lacrimal gland includes what 4 things?
nutrients, growth factors, glycoproteins, immunoglobulins (isotonic Na, K, Cl rich solutions)
The main lacrimal gland is _______ exocrine gland and secretes what 3 things
tubuloacinar; proteins, electrolytes, water
Name the 7 types of proteins the lacrimal gland secretes
- lysozyme
- lactoferrin
- lipocalin
- secretory immunoglobulin A
- epidermal growth factor
- transforming growth factor
- interleukins
Final tear fluid is a mixture of ______ rich fluid
Na-Cl
What is Sjogren’s Syndrome
it is a lacrimal gland dysfunction that leads to a dry eye condition
Severely dry eyes may lose _______ transparency
corneal
What is the final source of electrolytes in water in the aqueous layer tear film and why
conjunctiva; because it occupies a portion of the ocular surface much larger than the cornea
Is the mechanism for conjunctival electrolyte and water secretion similar to that of the lacrimal gland
yes very similar
The conjunctival Cl- secretion into tears accounts for approximately ______ to _____ percent of the active transport of the conjunctiva
60; 75
What are the minor contributors to the aqueous component
corneal and conjunctival epithelium