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
T/F Corneal and conjunctival eptithelium release proteins
F; the do not release proteins
What is the major source of the mucus layer of the tear film
conjunctiva goblet cells
Mucins are collections of ______
large heterogenous glycoproteins (protein backbone with carbohydrates side chains; 50% carbohydrate by mass)
What is the secondary source of the mucus layer
stratified, squamous cells of conjunctiva and corneal epithelial (REMEMBER PRIMARY SOURCE ARE GOBLET CELLS FROM THE CONJUNCTIVA)
Where can the punctum be found
the opening of the medial portion of each eyelid (where the eyelashes end)
How large is the opening of the punctum A) 0.1mm B) 0.2mm C) 0.3mm D) 0.5mm
0.3 mm
The delicate drainage structures are know as
superior and inferior canaliculi
The canaliculi are \_\_\_\_\_ in length and \_\_\_\_\_ to \_\_\_\_\_\_in diameter A) 10 mm, 1 to 1.00mm B)10 mm, 10 to 1.00mm C) 10 mm, 0.5 to 1.00mm D)10 mm, 5 to 1.00mm
10 mm; 0.5; 1.00 mm
Where does the superior and inferior canaliculi drain into
nasolacrimal sac
Does everyone have a common canaliculi
No; formed in 90% of individuals, so 10% are without
The superior and inferior canaliculi are lined with _____ ______ ______ and it is surrounded by ______ muscles
stratified squamous epithelium; orbicularis
in the nasolacrimal sac what is present at the opening of the duct into the nose
Hasner’s valve (a mucosal flap)
Under normal conditions how much of the secreted tear volume is loss to evaporation? A) 15-30% B) 15-20% C) 10-20% D) 10-25% Where are the remaining tears drained?
10-25%
lacrimal system into the nose
due to ______, _____ times as many tears drain through the inferior punctum as to the superior
gravity; 4
what can be used to occlude the punctum and which punctum would you occlude first
punctal plug; inferior punctum
adequate____ and ______of tears is necessary for optimal visual function
drainage , secretion
Contraction of the ______ orbicularis muscle fibers during eyelid closure _____ and _____ the canaliculi
The _____ pumps tears towards the _____ sac
These two concepts are part of what theory?
pretarsal; compresses; shortens
shortening; lacrimal
The lacrimal pump theory (jones-jones wobig)
T/F Epiphora (excessive tearing) in the setting of facial paralysis highlights the important contributions of the orbicularis muscle to meibomian gland secretion
F; Epiphora (excessive tearing) in the setting of facial paralysis highlights the important contributions of the orbicularis muscle to lacrimal outflow
The volume of tears drained per ______ is ______ ml. According to Cahlin and Cheng
However, according to Rosengren the volume is _____ ml
blink; 2
1.8
T/F we can remove 2 ml per blink if needed (max capacity but we function at minimal capacity)
T
T/F we function far above capacity which allows for absorption of some of the volume in route to the nasal cavity
F; below capacity
Lacrimal drainage capacity has been shown to be correlated to the ______ rate when the nasolacrimal duct is in _____ position
blink; horizontal
What was used to assess the role of blinking in lacrimal drainage
Movements of the tear fluid were made visible by instilling _____ ______ into the tear film
Doane emphasize compression of the ______ in the nasolacrimal sac during eyelid closure
high speed photography
carbon black
canaliculi
T/F Cahlin and Cheng showed that gravity tended to decrease lacrimal drainage
F; increase
______ blink transports more tears than ______ minute of basic secretion
one; one
Siphoning (the flow of liquid through tubes) by the lacrimal sac occurs during ______ of the blink, not during _______.
What theory/model is that?
relaxation; closure
Doane Blink Theory/Model
T/F When there is complete closure of the eyelid, fluid is drawn into the canaliculi from tear
F; it is drained into the canaliculi at the end of a blink when the eyelid is open
What situations can lead to insufficient tear layers
atrophy of lacrimal gland (sjorgen’s), increase in age, compromised innervation
What are the 7 causes of dry complaints of CL wearers
- insufficient tears
- poor tear quality (decreased - short break up time)
- infrequent blinking
- incomplete blinking
- reflex tears (low osmolarity)
- poor CL wetting
- blepharitis (inflammation of the eyelids)
Normal tear productions vary with _____ but not _____
age; gender
T/F physical and psychological stimulation can vary normal tear production
T
After having ______ surgery, almost every patient will have a ______ _______ eye complaint
Lasik; acute (suddenly severe but it will go away) dry
If the secondary Jone’s test is done and there is positive dye where is the blockage
canaliculi
T/F if you are doing the secondary jone’s test there is a blockage in your lacrimal system
T
If the secondary Jone’s test is done and there is negative dye where is the blockage
block or pump dysfunction
What are three quantitative tests that can be used to test the quantity tears produced
- Schimers with topical anesthetic (greater than or equal to 15 mm over 5 mins)
- tear meniscus height at lower lid margin (0.75 mm) HE LIKES TO USE THIS AS A TEST QUESTION!
- Phenol red thread (greater than or equal to 20 mm over 15 secs)
What are the two qualitative tests that can test tear film stability
- invasive TBUT (tear break up time) with fluoroscene
2. noninvasive keratometer miers
T/F for both the TBUT and keratometer miers normal tear film stability is greater than or equal to 20 seconds
F; it is 10 secs
When would you do a Schirmer’s test
dry eye and/or excessive watery eye
What does ocular surface assessment test and what are the 2 techniques
surface integrity
tissue sampling - impression cytology and staining techniques
Why would you need anesthesia in a Schirmer’s test
so you are not testing for reflex tearing
Where would you place the strip on the Schirmer’s test, temporal or medial
temporal because we are trying to test the quantity of tears produced and not the spreading
In the Schirmer’s test for individuals less than 60 years greater than or equal to ______ mm is the norm. For individuals older than 60 years ______ mm may be the norm.
15; 10
Which part on the Schirmer’s test do you measure?
the wet part
What 5 things affect the Schirmer’s test outcome
- placement of the strip nasal versus temporal
- age variation
- effect of anesthesia
- reflex tearing
- subjective measurements
In the Schirmer’s test mild dry eye is _____ to ______ mm, moderate dry eye is ______ to ____ mm, and severe dry eye is _____ mm.
A) 14-9 ,8-7,less than 4
B) 14-9 8-4 less than 4
C) 14-10 8-4 less than 4
D) 20-9 8-7 less than 4
Measurements should be taken after how many minutes?
14; 9; 8; 4; less than 4
5
_____ cells secrete fluid having an _____ composition similar to that of ______
acinar; electrolyte; plasma
What type of pump drives the secretion of fluid from the acinar cells
the sodium potassium ATPase pump (Na out, K in)
If you have a low flow rate in the secretion of fluid of the acinar cells what would the fluid be considered
hypertonic
Infusion causes an unequal solute concentration among the fluid compartments
If you have an increase flow rate in the secretion of fluid of the acinar cells what would the fluid be considered
isotonic
______ cells modify the acinar cell fluid by secreting a fluid in _____.
The lacrimal gland fluid contains what ions and which ones are higher in concentration compared to the plasma?
ductile; KCl
Na, K, Cl, HCO3 (Bicarbonate), Ca and the two that are higher are K and Cl.
Regulated by the nerves that innervates the secretory cells and by the ______ and ______ hormones present in the blood stimulate secretion.
peptide; steroid
T/F The lacrimal gland is innervated by only parasympathetic and sensory nerves
F; it is parasympathetic, sympathetic, and sensory
Nerves and peptide hormones stimulate secretion of _____, ______ and the regulated _______.
______ hormones stimulate the secretion of constitutive proteins
electrolytes; water; proteins
steroids
T/F Stimulation of the sympathetic nervous system results in no change in tear secretion
T
T/F Parasympathetic fibers of CN 5 are responsible for secretion and are main contributor to tear film
F; it is CN 7
What 4 things cause a secretory cell stimulation and how?
- sensory nerves at optic surface activates para/sympathetic nerves to stimulate lacrimal gland protein, electrolyte and water secretion
- bright light hitting the optic nerve induces reflex lacrimal gland secretion
- acetylcholine and vasoactive intestinal peptide (VIP) are both potent stimuli of regulated protein, electrolyte, and water secretion
- norepinephrine stimulates protein secretion
What is the mucous producing tissue lining the ocular surface
conjunctiva
T/F conjunctiva is on the external side of the upper and lower lid
F; internal side
The conjunctiva provides the passage for the secretion of which glands
lacrimal and accessory lacrimal glands
conjunctiva is _____ secreting tissue
sero-mucous
Normal conjunctiva epithelium contains 6000 ______ and 14000 _______
neutrophils; lymphocytes
T/F the conjunctiva is the most immunologically active tissue of the external eye
T
What three things can provoke a conjunctival rxn
infections, allergies and inflammation
Rxns are categorized by what two structural changes in the conjunctiva
papillae formation (raised inflamed areas) and follicle formation
How is that papillae distinguished from follicles
by the present of blood vessels in their centers
T/F papillae contains only neutrophils
F; neutrophils (abundant type of WBC’s) and eosinophils (1st line of defense against infections,WBC’s)
T/F The papillae rxn is most commonly found in the lower lids
F; upper lid must evert the eyelid in order visualize it
Follicles are clear fluid fill pockets containing ______ and ______
lymphocytes; macrophages
T/F Follicles have no blood vessels passing above or below always within
F; follicles have blood vessels passing either above or below, never within
Eosinophils and basophils (WBC) are only found in the conjunctival epithelium of what 2 diseases
Vernal conjunctivitis and Giant papillary conjunctivitis
T/F Are eosinophils and basophils are found normal conjunctival epithelium
FALSE!!! eosinophils and basophils are not found in normal conjunctival epithelium only found in vernal and giant papillary conjunctivitis
When the contact lens is dislocated from cornea and not visible where can it go and why
most likely located in superior fornix sense it has the greatest depth
What are the two layers of the conjunctiva
epithelium and stroma
Conjunctival epithelium has A) to layers and has a different organization then the ____epithelium which has B) _ to_ layers
A) 3-6 B) 5-8
A) 4-5 B) 6-7
A) 2-4 B)5-7
2,4
corneal
5-7
A local thickening occurs where in the conjunctival epithelium
at the limbus , where conjunctival epithelium is continuous with corneal epithelium
What is immediately peripheral to the limubs?
palisades of Vogt
What three things can be found at the palasades of Vogt
- epithelium has thickened 4 or 5 fold
- increase in wing cells
- limbal stem cells reserve: continually contribute cells to cornea and serve as reserve source in the event of trauma
How wide are goblet cells on average A) 0.1microns B) 11microns C) 13microns D) 10microns
11 micron
Where are goblet cells sparse and where are they more frequent?
sparse in bulbar conjunctiva
frequent in fornix and palpebral conjuntiva
Goblet cells are _____ mucin-secreting glands within conjunctival epithelium
unicellular
Stroma lies ____ the conjunctival epithelium
below
What two layers does the stroma consist of ?
adenoid layer and deep fibrous layer
T/F stroma is poor network of capillaries
F. rich network of capillaries
What is need for regeneration of epithelium and formation of new goblet cells ?
Rich supply of nutrition
Mast cells are found in _____ layer of conjunctival stroma with other _____ cells
adenoid, inflammatory
Where are mast cells extremely numerous in \_\_\_\_\_\_\_ , and \_\_\_\_\_\_\_ cells/mm^3 A) corneal stroma, 6000 b) conjunctival stroma , 3000 C) conjunctival stroma, 6000 D) conjunctival stroma, 60000
in conjunctival stroma, 6,000 cells per cubic mm
Mast cells are \_\_\_ micrometers in diameter A)30 b) 40 c)50 D)20
20
What are mast cells responsible for and what do they contain?
immediate hypersensitivity reaction,
contain :
1. several preformed chemical mediators of inflammation
2. histamine and heparin
Mast cells are equivalent to circulating _______
basophils
What happens when mast cells are bound by IgE
- Dramatic changes occur in mast cell membrane and cytoplasm.
- physical properties change so that membrane become more permeable to calcium
- leading to edema(swelling)
T/F metochromatic stain different with the same dye
T
In infections of conjuntiva what vessels are engorged
superifivial posterior vessels
What two types of inflammation engorge deep ciliary vessels
keratitis (corneal inflammation) or iritis (iris inflammation)
What system is richly supplied in the conjunctiva and nowhere in the globe itself
lymphatic system
T/F there is lymphatics within the globe itself
F. there is no lymphatics within the globe itself
The flow of lymph is generally in _______ direction toward _____ extremes of id, eventually connecting with parotid node
temporal, lateral
The _______ route leads to submandibular lymph gland
medial
