L48: Oral Environment 2 Flashcards
(21 cards)
What are the three major salivary glands?
- Parotid;
- Submandibular;
- Sublingual.
Which pair of major salivary glands produce predominantly serous secretions?
Parotid
Which pair of major salivary glands produce predominantly mucous secretions?
Sublingual
Which pair of major salivary glands produce mixed secretions?
Submandibular
Name some of the most important components of saliva for maintenance of the oral cavity?
- Enzymes: Lipase and amylase;
- Antimicrobials: IgA, lactoferrin, histatins and cystatins;
- Buffers: Bicarbonate, phosphate (+ histadine from histatins).
What is amylase?
An enzyme that breaks down polysaccharides
What is lipase?
An enzyme that breaks down lipids (fats)
What salivary antimicrobials are effective against s. mucans?
Lactoferrin and histastins
What is lactoferrin?
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.
The production of saliva is a …-stage mechanism?
Two
The first stage of salivary production occurs in…
the acinus
The second stage of salivary production occurs in…
the ducts (modification)
Primary secretions of saliva are…
isotonic (similar tonicity to blood plasma)
Final secretions of saliva are…
hypotonic
In the second stage of saliva production, … and … are reabsorbed
- Na+;
- Cl-.
In the second stage of saliva production, … and … are secreted
- K+;
- HCO3-.
Why does water not leave the salivary duct, during the second stage of saliva production?
Membranes are impermeable to water
Describe the tonicity of salivary secretions during its production.
- 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.
What ions are rich in salivary secretions?
K+ and HCO3-
Explain the mechanism of bicarbonate production in the body.
Carbonic anhydrase: CO2 + H2O + carbonic anhydrase > HCO3- + H+
The major salivary glands are extrinsic salivary glands, where does the parotid duct secrete into the oral cavity?
Stensen’s duct, upper second molars
