Salivary Glands

Question 1

Salivary Glands are which subtype of exocrine glands?

Answer 1

Merocrine (They use exocytosis of vesicles and membrane transport of salts and water)

Question 2

How are Salivary glands structurally laid out?

Answer 2

Compound (Branching) Tubuloacinar

Question 3

What do Salivary Glands develop from?

Answer 3

Mesenchyme

Question 4

Parotid and Minor Salivary glands arise from what?

Answer 4

Ectoderm

Question 5

Submandibular and sublingual arise from what?

Answer 5

Endoderm

Question 6

What does the Parenchymal tissue (secretory) of salivary glands arise from?

Answer 6

Oral epithelium (ectoderm) or endoderm

Question 7

What does Stromal tissue (septa and capsule) of salivary glands arise from?

Answer 7

Mesenchyme of mesodermal or neural crest origin

Question 8

Which salivary glands are first to begin development?

Answer 8

Parotid (6th week) from the crease between maxillary and mandibular swellings.

Question 9

Which gland is second to begin development?

Answer 9

Submandibular gland (end of 6th/beginning 7th) from sulcus surrounding sublingual folds

Question 10

Which gland is last to begin development?

Answer 10

Sublingual gland (8th week) from sulcus surrounding sublingual folds (lateral to the submandibular buds)

Question 11

When do minor salivary glands begin to develop?

Answer 11

Around 12 weeks from both ectoderm and endoderm

Question 12

Myoepithelial cells arise from what? and when?

Answer 12

Neural Crest around 24-25 weeks to surround acini

Question 13

What two things is unique about the parotid?

Answer 13

1-Has intraglandular lymph nodes

2-Epithelial buds brand and extend around the facial nerve

Question 14

What are the 6 stages of salivary gland development?

Answer 14

1-Bud formation
2-Formation and Growth of Epithelial Cords
3-Inititiation of branching in terminal parts of the cord
4-Branching and lobule formation
5-Canalization of presumptive ducts
6-Cytodifferentiation

Question 15

What happens during Stage 1?

Answer 15

• Mesenchyme induces proliferation in epithelium
• Bud forms
• Bud separates from mesenchyme by basal lamina

Question 16

What happens during stage 2 ?

Answer 16

• Solid cord forms

- Basal lamina maintained between cord and mesenchyme

Question 17

What happens during stage 3?

Answer 17

• Proliferation of epithelial cord
• Branching inato terminal bulbs (presumptive acini)
• Formation of first cleft

Question 18

What happens during stage 4?

Answer 18

• Branching continues at terminal portions to form tree-like system
• CT differentiates around branches
• Formation of lobules

Question 19

What happens during Stage 5?

Answer 19

• Canalization of epithelial cord
• Lumins appear then branch into ducts
• Tight junctions form between cells

Question 20

What happens during Stage 6?

Answer 20

• Cytodifferentiation

- formation of functional acini and intercalated ducts

Question 21

What 3 things can terminal bulb cells differentiate into?

Answer 21

1-Acinar cells
2-Myoepithelial Cells
3- Duct cells

Question 22

Which collagen type activates branching?

Answer 22

Collagen Type III

Question 23

Which collagen type(s) maintains and supports branching?

Answer 23

Collagen Types I, IV

Question 24

What chemical inhibits N-Linked glycosylation?

Answer 24

Tunicamycin (results in decreased epithelial expansion with similar branching amounts)

Question 25

Where is the mitotic activity localized in growing buds?

Answer 25

Peripheral regions

Question 26

Which growth factor is important for stalk elongation?

Answer 26

FGF

Question 27

Which growth factor regulates branching?

Answer 27

EGF

Question 28

What is an necessary extracellular component for salivary gland branching?

Answer 28

Extra Cellular Matrix (ECM)

Question 29

What is required for full functional secretory components?

Answer 29

Solid diet and masticatory stimuli