Salivary gland Flashcards
How much saliva is produced per day?
600-1000 mL/day
List the electrolytes found in saliva (9)
- Na+
- K+
- Cl-
- HCO3-
- Ca2+
- Mg2+
- HPO4 2-
- SCN-
- F-
List the secretory proteins/peptides found in saliva (10)
- Amylase
- Proline-rich proteins
- Mucins
- Histatin
- Cystatin
- Peroxidase
- Lysozyme
- Lactoferrin
- Defensins
- Cathelicidin-LL37
List the immunoglobulins found in saliva (3)
- IgA
- IgM
- IgG
List the organic components found in saliva
- Glucose
- Amino acids
- Urea
- Uric acid
- Lipid molecules
List other components found in saliva
- Epidermal growth factor
- Insulin
- Cyclic adenosine monophosphate-binding proteins
- Serum albumin
What are the 7 functions of saliva?
- Protection
- Buffering
- Tooth integrity
- Antimicrobial activity
- Tissue repair
- Digestion
- Taste
How does saliva provide protection?
- Clearance
- Lubrication
- Thermal/chemical insulation
- Pellicle formation
- Tannin binding
What is the effect of saliva buffering?
- pH maintenance
2. Acid neutralisation
How does saliva maintain the integrity of the tooth?
Enamel maturation and repair
How does saliva assist in digestion?
- Bolus formation
2. Starch & triglyceride digestion
How does saliva assist in taste?
- Solution of molecules
2. Maintenance of taste buds
What is the salivary flow rate at rest?
0.2-0.4mL/min
What is the salivary flow rate when stimulated?
2-5mL/min
What is the pH of saliva?
6.7-7.4
What is the salivary flow rate from the parotid gland at rest?
0.04mL/min
What is the salivary flow rate of the parotid gland stimulated?
1-2mL/min
What is the pH of saliva from the parotid gland?
6.0-7.8
What is the salivary flow rate from submandibular gland at rest?
0.1mL/min
What is the salivary flow rate from salivary gland stimulated?
0.8mL/min
Name the 3 major salivary glands
- Parotid gland
- Submandibular gland
- Sublingual gland
Which major salivary gland is the largest?
Parotid salivary gland
Which major salivary gland is the smallest?
Sublingual salivary gland
Which major salivary gland is the second largest?
Submandibular salivary gland
Name the ducts of the salivary glands:
- Parotid
- Submandibular
- Sublingual
- Stenson’s duct
- Wharton’s duct
- Bartholin’s duct
Describe the type of secretion produced by parotid
Mostly serous (rich & amlyase & proteins)
Which major salivary gland contributes most to the total saliva content?
submandibular (produces 60% of saliva content)
Which salivary gland starts developing 8-12 weeks of embryonic life>
sublingual gland
When does the parotid gland develop?
4-6 weeks of embryonic life
When does the submandibular gland develop?
6 weeks of embryonic life
How much saliva does the parotid gland produce?
30%
How much saliva does the sublingual gland produce?
5%
Describe the secretion type produced by sublingual gland
Mostly mucous
Describe the secretion type produced by submandibular gland
Mainly serous, partially mucous
How many minor salivary glands are present in the oral cavity?
450-1000
Describe the secretion type produced by minor salivary glands
Mainly mucous, partially serous
List the some minor salivary glands
- Labial
- Lingual
- Palatal
- Buccal
- Glossopalatine
- Retromolar
What is the name of the minor salivary gland located on the dorsal surface of tongue?
Von Ebner
Where is the Blandin Nuhn located?
Ventral surface of the tongue
How does saliva flow through the salivary ductal system?
- Parenchyma (epithelial cells)
- Intercalated duct
- Striated duct
- Excretory duct
- Main excretory duct
Where are the parenchyma salivary secretory cells located?
Spherical & tubular secretory end piece
Which ducts are considered intralobular?
Intercalated & striated
Which ducts are considered interlobular
Excretory & main excretory ducts
What is the role of the striated duct?
Saliva modification through reabsorption and secretion of electrolytes
Where is the primary saliva produced?
Spherical & tubular secretory end piece
Where are the myoepithelial cells located?
Between basal lamina and epithelial secretory cells.
They are associated with secretory acini and intercalated ducts
What is the function of the myoepithelial cells?
- Surrounds the acinus to squeeze out the salivary secretion from the end piece into the duct system
- Contractile
Histologically, which major salivary gland would have the most adipocytes?
Parotid salivary gland
Describe how you would histologically differentiatie between parotid, submandibular and sublingual salivary gland
- Parotid salivary gland has more adipocytes
- It would be easy to identify the mucous acini in submandibular gland
- Parotid gland: purple
- Submandibular gland: purple & some pink
- Sublingual gland: pink & some purple
Describe the two methods of salivary secretion
- Main regulated pathway:
- Cells store the protein
- Upon neural signal, the cells secrete protein by stored granule exocytosis - Second constitutive pathway:
- Cells do not store the protein
- Cells secrete it continuously by vesicular mechanism. Vesicles travel directly from the Golgi apparatus to the plasma membrane
- Some proteins pass into the lumina, some pass in the opposite direction to reach the interstitial fluid
- Transcytosis: substances, such as IgA, are present in the interstitial tissue pass across the cell from the basolateral to the apical membrane
Outline the pathway in secretory protein synthesis, storage and stimulated exocytosis
- In rough ER, protein synthesis occurs
- Protein transported via Golgi apparatus to transface
- Initial storage within immature granules
- Concentration of secretory proteins in mature storage granules
- Exocytosis of stored proteins into lumen of acinus
List the vesicular protein secretory pathways likely to operate in the parotid acinar cells
- Storage granule pathway
- Constitutive-like pathway (no storage of protein)
- Constitutive pathway to apical membrane
- Constitutive pathway to basolateral membrane
- Transcytosis from basolateral to the apical
Where does salivary modification occur?
striated duct
Outline how saliva is modified in the striated duct
- Na+ & Cl- are resabsorbed via
Na+/H+ & Cl-/HCO3 -exchangers in the luminal membrane - Na+ exists at the basolateral surface via Na+/K+ adenosinetriphosphatase and Cl- exists via channel
- K+ channels at the basolateral surface maintain electroneutrality
- Na+/H+ compensates for intracellular acidification
Where are mucocles usually located?
Lower lip
- almost never the upper lip - consider alternative diagnosis of salivary gland neoplasm
Outline how the mucocle is formed
- Damage to minor salivary gland duct and extravascation of saliva
- Saliva leaks into surrounding tissues causing inflammation
- Saliva pools to form a mucocele with CT wall
What is sialolithiasis?
Salivary gland stone
Where is sialolithiasis most likely to occur?
Submandibular gland.
- due to the nature of secretion (more mucous than serous)
Define xerostomia
Subjective feeling of having dry mouth
Define hyposalivation
Measured reduction in the production of saliva
What is the salivary flow which constitutes as hyposalivation
0.1mL/min
List some organic causes of xerostomia
- Sjogren’s syndrome
- Irradiation
- HIV
- Hep C
- Iron deposition
List some function causes of xerostomia
- Dehydration
- Fluid loss
- Haemorrhage
- Anxiety states
- Depression
- Drugs
- Psychogenic
List some drugs that causes xerostomia
- Antihistamines
- Tricyclic & antidepressants
- Bronchodilators
- Antiemetics (against vomitting & nausea)
- ‘Cold cures’ containing ephedrine
- Appetite suppressants
- Decongestants