Week 2: Salivary gland Flashcards
Functions of saliva
3 listed
- Lubrication
- Solvation
- Oral and Dental health
How does saliva serve to lubricate?
- Lubricates and softens food
- Aids in swallowing
How does saliva serve in solvation
Facilitate taste sensations
How is saliva important for oral and dental health?
5 listed
- Rinses teeth and buccal mucosa
- antibacterial function
- lysozyme (digests peptidoglycan layer of bacterial cell wall)
- Lactoferrin (chelates iron to prevent bacterial growth)
- Immunoglobulin A (immunologic surveillance)
Describe Salivary gland structure
Identify structure and components
What are the major cell types lining the salvion?
3 listed
- Acinar cells
- Ductal cells
- Myoepithelial cells
Identify structures and components
Describe the structure of an acinar unit
Identify structures and components
Acinar unit
Describe how the salivary glands are regulated:
vagal stimulation
Vagus nerve -> ACh -> ^IP3 by phospholipase C -> release of intracellular Ca2+ stores -> causes vesicles with stored material to move to the plasma membrane in order to secrete contents into acinus & stimulates Cl- channel which causes secretion of Cl- into the Acinus and because this is an electronegative ion Na+ follows thereby drawing water out of the cell by osmosis
Also, (still hypothetical) speculation that Ca2+ will stimulate aquaporin, which is a water transporter
What is secreted by salivary gland cells?
3 listed
- Amylase (carbohydrate digestion)
- Lysozyme (digests peptidoglycan bacterial cell walls)
- Lactoferrin (chelates iron that bacteria need iron to generate their electron gradients for energy production)
What is the Cephalic phase of digestion?
the salivary glands become stimulated and activated based upon seeing food so you secrete digestive and antimicrobial enzymes and a lot of water in preparation for ingesting food
Describe other effects of vagal stimulation f the salivary glands
Describe ion concentrations around and inside salivary glands
Describe salivary gland acinus [Ion] in unstimulated state
Describe salivary gland acinus [Ion] during the stimulated state
K+ resorption transporters don’t have sufficient time
Where does the excess HCO3- come from in salivary gland stimulation?
Ductal cells through the enzyme Carbonic anhydrase
CO2 + H2O -> HCO3- + H+
CO2 from metabolism from the 2 decarboxylation sites in the TCA cycle
What are the main proteins the salivary gland secretes
4 listed
lactoferrin
lysozyme
IgA for immunosurveillance
Amylase
What is starch?
Polymer of glucose broken down by amylase
repetitive α 1, 4 glycosidic linkage
First sources of digestion
2 listed
- mastication is mechanical does not break the chemical bonds
- amylase is first form of chemical digestion that breaks the chemical bonds
What types of glycosidic linkages can amylase digest?
β 1, 4 glycosidic linkage (cannot be digested by amylase)
This is cellulose and doesn’t contribute to metabolism directly, however, it adds bulk and hydration to stools preventing impaction and constipation
α 1, 4 glycosidic linkage can be digested by amylase
Primary and secondary saliva [ion]
Ion transporter review
Describe a salivary duct cell’s ion secretions unstimulated
Saliva buffering
Describe a salivary duct cell’s ion secretions stimulated
Identify structure and components
Mucin
Describe salivary IgA and transcytosis
Normal pH of saliva
~7.5
The duct(s) of gland(s) opening into the floor of the mouth is (are)
submandibular and sublingual
Main function of salivary duct is
To convey the saliva secreted by the terminal secretory units to oral cavity
Which of the following is not present in saliva
1) Lysozyme
2) Phosphate
3) Bicarbonate
4) Trypsin
Trypsin
Your saliva can reveal which of the following?
1) Eye color
2) Hair color
3) Age
Age
