Lacrimal System and Conjunctiva part 2

Question 1

what is a way to quantitatively test the tears produced

Answer 1

a Schirmer’s test

Question 2

what is the tear meniscus height at the lower lid margin

Answer 2

0.75mm

Question 3

what is a noninvasive way to test the tear film stability

Answer 3

with a keratometer (watching the mires to see if they stay stable and clear) about 10 sec

Question 4

what is an invasive way to measure the tear film stability

Answer 4

TBUT (tear break up time) with flourescein (10 sec)

Question 5

how can you test the ocular surface integrity

Answer 5

tissue sampling (impression cytology-counting goblet cells in conjunctiva) or staining techniques

Question 6

when would you give a Schirmer’s test

Answer 6

dry eye or excessive tearing

Question 7

what are the steps of the Schirmer’s test

Answer 7

instill anesthesia and wait a min, wipe excessive tears, place strip on temporal side, wait 5 min, record results

Question 8

why does the eye need to be numb for a Schirmer’s test

Answer 8

otherwise you are testing the reflex tearing, no the basic secretion

Question 9

why do you place the strip on the temporal side during a Schirmer’s test

Answer 9

because the tears drain medially and it will give a false measurement

Question 10

what is a normal outcome for the Schirmer’s test

Answer 10

greater than or equal to 15mm

Question 11

what is a variation of a normal result of a Schirmer’s test

Answer 11

an older individual (over 60) may only have 10mm but not complain of dryness or epiphora

Question 12

what can affect the outcome of a Schirmer’s test

Answer 12

placement of the strip in the eye, age, effect of anesthesia, reflex tearing, and subjective measurement

Question 13

what is a mild dry eye test result for Schirmer’s

Answer 13

9-14 mm

Question 14

what is a moderate dry eye result for Schirmer’s

Answer 14

4-8 mm

Question 15

what is a severe dry eye result for Schirmer’s

Answer 15

less than 4 mm

Question 16

what is the first stage of secretion of lacrimal gland electrolytes and water

Answer 16

the acini cells secrete a fluid that has an electrolyte composition similar to that of plasma

Question 17

what is the second stage of secretion of lacrimal gland electrolytes and water

Answer 17

as the fluid passes through the duct system, the ductal cells modify the fluid by secreting a fluid rich in potassium chloride (KCl)

Question 18

what drives acinar cell electrolyte secretion

Answer 18

a sodium potassium ATPase pumping sodium out of the cell and potassium into the cell

Question 19

what is the solution called at low fluid rates

Answer 19

hypertonic

Question 20

what is the solution called as the flow rate increases

Answer 20

isotonic

Question 21

how do the ductal cells modify the fluid as it passes through the duct system

Answer 21

by secreting a fluid rich in potassium chloride

Question 22

what ions does the lacrimal gland contain

Answer 22

Na+, K+, Cl-, HCO3, Ca2+ and trace amounts of other ions in the same concentration as plasma (except K+ and Cl- which are higher concentrations)

Question 23

what stimulates the cells to secrete

Answer 23

nerves, peptide and steroid hormones present in the blood

Question 24

what type of nerves innervate the lacrimal gland

Answer 24

parasympathetic nerves, sympathetic nerves, and sensory nerves

Question 25

what specifically do the nerves and peptide hormones stimulate secretion of

Answer 25

electrolytes, water and the regulated proteins

Question 26

what specifically do the steroid hormones stimulate

Answer 26

the secretion of the constitutive proteins

Question 27

does stimulation of the sympathetic nervous system result in change in tear secretion

Answer 27

no

Question 28

what parasympathetic nerves are responsible for the secretion of tears

Answer 28

CN 7 facial nerve

Question 29

what are 5 stimulants that can cause secretion of the lacrimal gland

Answer 29

sensory nerves at optic surface, a bright light hitting the optic nerve, acetylcholine and vasoactive intestinal peptide (VIP) and norepinephrine

Question 30

what is the conjunctiva

Answer 30

a mucous producing tissue lining the ocular surface (sero-mucous secreting tissue)

Question 31

what part of the external eye is the most immunologically active tissue

Answer 31

the conjunctiva

Question 32

how many neutrophils are in a normal conjunctiva

Answer 32

6,000

Question 33

how many lymphocytes are in a normal conjunctiva

Answer 33

14,000

Question 34

what can provoke conjunctival reactions

Answer 34

infections, allergy, and inflammation

Question 35

what are 2 structural changes in allergic reactions of the conjunctiva

Answer 35

papillae formation and follicle formation

Question 36

what are papillae

Answer 36

areas of conjunctival hypertrophy, contain eosinophils and neutrophils

Question 37

how can you distinguish papillae from follicles

Answer 37

papillae have blood vessels in the centers

Question 38

which lid, upper or lower, are papillae normally found in

Answer 38

the upper lid (must evert the lid to see them)

Question 39

what are follicles

Answer 39

clear, fluid-filled pockets, containing lymphocytes and macrophages

Question 40

what are 2 granulocytes that are not commonly found in normal conjunctiva epithelium

Answer 40

eosinophils and basophils

Question 41

what 2 diseases of the conjunctival epithelium have eosinophils and basophils present

Answer 41

vernal conjunctivitis and giant papillary conjunctivitis

Question 42

where does a CL usually end up in the eyelid when it becomes displaced

Answer 42

in the superior fornix since it has the greatest depth

Question 43

what are the two layers of the conjunctiva

Answer 43

epithelium and stroma

Question 44

how many stratified layers are there in the epithelium

Answer 44

2-4 stratified epithelial cells

Question 45

when the conjunctival epithelium becomes the corneal epithelium, how many stratified layers does it have

Answer 45

5-7, difference begins at the limbus

Question 46

what are located in the palisades of vogt

Answer 46

limbal stem cells and increased wing cells

Question 47

what are goblet cells

Answer 47

unicellular mucin-secreting glands (holocrine) within conjunctival epithelium

Question 48

which area of the conjunctiva has the most goblet cells

Answer 48

fornix and palpebral conjunctiva

Question 49

what does the conjunctival stroma consist of

Answer 49

adenoid layer, deep fibrous layer, and a rich network of capillaries

Question 50

why does the conjunctiva need a rich supply of nutrition

Answer 50

for regeneration of epithelium and formation of new goblet cells

Question 51

where are the glands of Wolfring located

Answer 51

in deep fibrous layer (tarsal plate)

Question 52

where are mast cells found

Answer 52

in adenoid layer of conjunctival stroma

Question 53

does the conjunctival epithelium normally have mast cells

Answer 53

no they are an inflammatory cell and usually found in the adenoid layer of the stroma

Question 54

when mast cells are present in the conjunctival stroma, how many are there

Answer 54

6,000 per cubic millimeter

Question 55

what is the diameter of a mast cell

Answer 55

20 micrometers in diameter

Question 56

what are mast cells responsible for

Answer 56

immediate hypersensitivity allergic reaction

Question 57

what do mast cells contain

Answer 57

several perforated chemical mediators of inflammation, histamine, and heparin

Question 58

what fills the cytoplasm of mast cells

Answer 58

30-100 metachromatic granules

Question 59

what happens when mast cells are bound by IgE (allergies)

Answer 59

dramatic changes occur in cell membrane and cytoplasm, physical properties change (membrane becomes more permeable to Ca++ ions) and leads to edema

Question 60

which blood vessels are engorged in conjunctival infections

Answer 60

superficial posterior vessels

Question 61

which blood vessels are engorged in keratitis or iritis

Answer 61

deep ciliary vessels

Question 62

does the conjunctiva have lymphatics

Answer 62

yes

Question 63

which way does the temporal lymph drain in the conjunctiva

Answer 63

towards lateral extremes of lid, eventually connecting with parotid node

Question 64

where does the medial conjunctival lymph drain

Answer 64

to the submandibular lymph glands