Lacrimal Gland

Question 1

What kind of gland is the lacrimal gland

Answer 1

Exocrine gland (like the mammary and salivary gland)

Question 2

Myoepithelial creates

Answer 2

Force for excretion of tears

Question 3

Lacrimal gland develops from multiple

Answer 3

Ectoderm buds at anterior superolateral orbit

Question 4

Lacrimal glands may not function fully for up to

Answer 4

6 weeks after birth

Might explain why newborn dont produce tears when crying

Question 5

When someone has extreme dry eye

Answer 5

Scar tissue will form over the cornea.

Question 6

Why dont artificial tears work too well

Answer 6

No growth factors

So there is nothing to stimulate the the epithelium to grow so it doesn’t help it heal

Question 7

During sleep, secretion of all major proteins and water

Answer 7

Is inhibited

Question 8

Total removal of the main lacrimal gland

Answer 8

Does not in itself lead to dry eye

Question 9

Removal of parasympathetic innervation to the lacrimal gland

Answer 9

Leads to rapid reduction in tear flow

Question 10

sensory input for cornea

Answer 10

CNV

Question 11

In healthy individuals, everyday ocular surface stimulation like mechanical irritation, low humidity, excess wind and CLs triggers

Answer 11

Neural signal that initiates reflex tear secretion (CNV)from the main and accessory lacrimal glands

Question 12

Tear reflex corneal nerves

Answer 12

CNV in

CNVII out

Question 13

Inflammation interrupts normal homeostasis and leading to

Answer 13

Ocular surface disease and dry eye involving Cytokines secretion which disrupts neural arc

Question 14

Basal aqueous secretion decreases with

Answer 14

Age and during sleep

Question 15

What causes aqueous secretion?

Answer 15

CNV (most common)

• dazzle (IIN)
• taste (VIIN)
• cough/sneeze /laugh (IXN, XN)

Question 16

True tear allergan

Answer 16

Irritates nasal mucosa to stimulate tear production

Question 17

Loss of water from the tear film leads to increased osmolarity and tears become more

Answer 17

Concentrated

Question 18

When evaporation increases (tonicity)

Answer 18

Tonicity increases

Question 19

When flow rate increases (tonicity)

Answer 19

Decreases

Question 20

When flow rate decreases

Answer 20

Tonicity increases

Question 21

When tonicity increases. Water is

Answer 21

Drawn from the cornea and the cells dry - irritating the eye

Question 22

Low tonicity leads to

Answer 22

Corneal edema

Question 23

High tonicity leads to

Answer 23

Corneal dehydration

Question 24

Diurnal rhythm in lacrimal secretion

Answer 24

NONE

Question 25

Tear production is stimulated by ___ agents. And decreased by _____agents.

Answer 25

Stimulated by cholinergic (policarpine) | Decreases by anto cholinergic (antihistamines)

Question 26

Newborns secrete tears in the first

Answer 26

24 hrs

Question 27

Hypotonic tears result from

Answer 27

Increased stimulation (more fluid & less dissolved protein)

Question 28

Hypertonic tears result from

Answer 28

Decreased stimulation | Evaporation (increase concentration by 10-20%)

Question 29

Hypersecretion of tears occur from

Answer 29

Irritation (CNV) | Foreign body, trauma, disease of cornea/conjunctiva of eyelid, nasal mucosa

Question 30

Hyposecretion of tears occur from

Answer 30

SJORGENS SYNDROME Inflammatory disease of salivary and lacrimal gland Scarring due to infection

Question 31

Typical tonicity range of tears

Answer 31

304-318 moms/L

Question 32

Osmolarity changes in CL wearers

Answer 32

Osmolarity decreases (tearing) initially then increases with adaptation

Question 33

Osmolarity of dry eye

Answer 33

Higher than 318 mosm/L

Question 34

Cornea temperature

Answer 34

Lower than the rest of the body (35-36 degrees celcius)

Question 35

Inflammatory enlargement of lacrimal gland

Answer 35

Dacryoadenitis | Unilateral, infection of some sort

Question 36

Approximately 50% of all lacrimal gland masses are

Answer 36

Inflammatory, other half are neoplasms

Question 37

The proper position of the eyelids against the globe and the position of the puncta to the tear lake are important for

Answer 37

Capillary attraction to draw the tears into the canaliculi

Question 38

If lids fold out , the tears wont touch the ocular surface and

Answer 38

Wont be able to drain (capillary attraction)

Question 39

Tears are removed by ____ attraction due to the vacuum formed in the lacrimal sac. This is influenced by ___ which creates the pressure.

Answer 39

Capillary | Orbicularis muscle

Question 40

The amount of tears present on the ocular surface at any given time is a function of both

Answer 40

Secretion of components that make up the tears and the drainage and evaporation of tears

Question 41

Drainage is via

Answer 41

Punctures -> canaliculi -lacrimal sac-> nasolacrimal duct to the valve of Hansel to nose

Question 42

Tears move into the puncta due to

Answer 42

Capillary attraction

Question 43

A sticky, watery eye with positive regurgitation on pressure over the lacrimal sac conforms the diagnosis

Answer 43

Epiphora Common in children Usually resolves on its own

Question 44

Nasolacrimal duct obstruction can cause

Answer 44

Tearing(epiphora) , crusting of eyelids, and lower lid erythema

Question 45

Nasolacrimal duct obstruction can occur due to

Answer 45

Chronic sinus disease, involutional stenosis, dacryocystitis or nasoorbital trauma

Question 46

Epiphora IN CILDREN can be caused by

Answer 46

Obstruction of nasolacrimal passage or NON OBSTRUCTIVE factors such as EYELID MALPOSITION, pump insufficiency , tear film instability, or hypersecretin

Question 47

Epiphora in adults is caused by

Answer 47

Disturbed ocular surface tear flow such as lid malpositon (dry eye, blepharitis, TRICHIASIS) ECTROPION

Question 48

In adults most common cause of epiphora is

Answer 48

Nasolacrimal duct obstruction

Question 49

Most common cause of inflammation of the canaliculus

Answer 49

Gram positive rod

Question 50

Severe dacrocytis can

Answer 50

Break through the skin

Question 51

Acute dacryocystitis is

Answer 51

Inflammation of the punctum | May have a fever - tells you there is in infection

Question 52

Disorders of the tear drainage can be caused by (2)

Answer 52

Irritation of ocular surface or occlusion of any part of the drainage system

Question 53

Lower cannaliculus drains 60% of the tear layer due to

Answer 53

Gravity

Question 54

Irrigation of the lower lacrimal system under topical anesthetia shows

Answer 54

How much drains

Question 55

Dacryocystitis

Answer 55

Obstruction of nasolacrimal duct