L48: Oral Environment 2

Question 1

What are the three major salivary glands?

Answer 1

• Parotid;
• Submandibular;
• Sublingual.

Question 2

Which pair of major salivary glands produce predominantly serous secretions?

Answer 2

Parotid

Question 3

Which pair of major salivary glands produce predominantly mucous secretions?

Answer 3

Sublingual

Question 4

Which pair of major salivary glands produce mixed secretions?

Answer 4

Submandibular

Question 5

Name some of the most important components of saliva for maintenance of the oral cavity?

Answer 5

• Enzymes: Lipase and amylase;
• Antimicrobials: IgA, lactoferrin, histatins and cystatins;
• Buffers: Bicarbonate, phosphate (+ histadine from histatins).

Question 6

What is amylase?

Answer 6

An enzyme that breaks down polysaccharides

Question 7

What is lipase?

Answer 7

An enzyme that breaks down lipids (fats)

Question 8

What salivary antimicrobials are effective against s. mucans?

Answer 8

Lactoferrin and histastins

Question 9

What is lactoferrin?

Answer 9

A protein that is effective as an antimicrobial (especially S. mutans!).

• Binds to iron, and is therefore effective against bacteria that require iron;
• Binds directly to bacteria to cause agglutination, and easy removal.

Question 10

The production of saliva is a …-stage mechanism?

Answer 10

Two

Question 11

The first stage of salivary production occurs in…

Answer 11

the acinus

Question 12

The second stage of salivary production occurs in…

Answer 12

the ducts (modification)

Question 13

Primary secretions of saliva are…

Answer 13

isotonic (similar tonicity to blood plasma)

Question 14

Final secretions of saliva are…

Answer 14

hypotonic

Question 15

In the second stage of saliva production, … and … are reabsorbed

Answer 15

• Na+;

- Cl-.

Question 16

In the second stage of saliva production, … and … are secreted

Answer 16

• K+;

- HCO3-.

Question 17

Why does water not leave the salivary duct, during the second stage of saliva production?

Answer 17

Membranes are impermeable to water

Question 18

Describe the tonicity of salivary secretions during its production.

Answer 18

• Primary secretions are isotonic, both ions (Na+ and Cl-) and water are pumped into the acinus of the salivary gland;
• Once the secretions travel to the duct, membranes are impermeable to water but ions are reabsorbed so the final secretions are hypotonic.

Question 19

What ions are rich in salivary secretions?

Answer 19

K+ and HCO3-

Question 20

Explain the mechanism of bicarbonate production in the body.

Answer 20

Carbonic anhydrase: CO2 + H2O + carbonic anhydrase > HCO3- + H+

Question 21

The major salivary glands are extrinsic salivary glands, where does the parotid duct secrete into the oral cavity?

Answer 21

Stensen’s duct, upper second molars