Lacrimal Anatomy

Question 1

3 components of lacrimal systems?

Answer 1

Secretory, Distribution, Elimination

Question 2

General purpose of lacrimal gland?

Answer 2

Produces majority of tear fluid

Question 3

Location of lacrimal gland to orbit?

Answer 3

Superior temporal aspect of orbit

Question 4

Lacrimal gland is divided into 2 portions/lobes by…

Answer 4

levator aponeurosis (of levator muscle)

Question 5

2 portions/lobes of the lacrimal gland?

Answer 5

Orbital, palpebral (smaller)

Question 6

2 lobes of the lacrimal gland are connected by (…), which mostly originate in (orbital/palpebral) lobe and traverse (orbital/palpebral) lobe to open into (…)

Answer 6

Ducts, orbital, palpebral, superior fornix

Question 7

Acini are made up of clusters of (…) surrounding a central (…)

Answer 7

Secretory cells, lumen.

Question 8

Lobules of the lacrimal gland consist of many (…)

Answer 8

acini

Question 9

The lacrimal gland is a (…) gland (consider structure)

Answer 9

Tubulo-acinar, meaning, tubular in shape with a rounded (acinar) end.

Question 10

interlobular ducts of the lacrimal gland open into the (…)

Answer 10

superior temporal fornix.

Question 11

Lumen of acini merge to form (…) ducts which then merge to form (…)

Answer 11

intra-lobular, interlobular ducts

Question 12

Acini consist of clusters of (…), that secrete into a (…)

Answer 12

secretory cells, central lumen

Question 13

Within lacrimal glands, considering the immune system, which cells are also present? (2 cell types)

Answer 13

Myoepithelial cells and lymphocytes.

(Myoepithelial cells are attached to the luminal cells and control many aspects of luminal functions. They regulate the flow of fluid and control the entry and exit of nutrients, electrolytes and other growth factors.)

Question 14

Accessory lacrimal glands vary in number and size, producing around (%) of aqueous tear production.

Answer 14

~10%

Question 15

Glands present in accessory lacrimal glands? (2)

Answer 15

Glands of Krause (in fornix), Glands of Wolfring (along orbital margin of tarsal plate)

Question 16

Location of glands of Krause?

Answer 16

accessory lacrimal gland, present in fornix

Question 17

location of glands of Wolfring?

Answer 17

accessory lacrimal gland, present along orbital margin of tarsal plate.

Question 18

Innervation of the lacrimal gland (2)

Answer 18

Autonomic input
* Parasympathetic nerve supply
* Sympathetic nerve supply

Sensory input
* Via lacrimal nerve (branch of trigeminal nerve)

Question 19

Activation of parasympathetic nerve supply of lacrimal gland results in (…)

Answer 19

Tear production.

Question 20

Parasympathetic nerve fibres
* Derived from (1) of (2) nerve in brain stem
* Travel along (3) nerve
* Synapse at (4) (beneath orbit)
* Fibres join (5) nerve, then (6) nerve and (7) nerve
* Axons terminate around (8) of lacrimal gland

Answer 20

1. lacrimal nucleus,
2. facial,
3. facial,
4. pterygopalatine ganglion,
5. maxillary,
6. zygomatic,
7. lacrimal,
8. secretory cells

Question 21

Innervation of lacrimal gland: Activation of parasympathetic receptor on secretory cell leads to activation of (…) (intra-cellular messengers)

Answer 21

G proteins

Question 22

Innervation of lacrimal gland: Activation of G proteins leads to activation of (…), resulting in?

Answer 22

Enzyme systems

Resulting in secretary granules bind to cell membrane and proteins secreted into lumen, ion channels open ions and water secreted into lumen

Question 23

Activation of enzyme systems result in (…) bind to cell membrane and (…) secreted into lumen
→ (…) open, Ions and water secreted into (…)

Answer 23

Secretory granules, proteins, Ion channels, lumen.

Question 24

Steps of innervation of lacrimal gland and tear production (parasympathetic)

Answer 24

1. Activation of parasympathetic receptor on
   secretory cells
2. Activation of G proteins
3. Activate enzyme systems.

Question 25

Other aspects that can lead to increased tear production? (2)

Answer 25

Hormones, other endogenous modulators