Salivary glands 11/10/15 Flashcards
What are the digestive functions of saliva?
- taste
- Lubricant
- Initiates digestion of starch
- Initiates digestion of fat
What are the 3 major salivary glands?
- Parotid
- Submandibular
- Sublingual
Sublingual is mostly _______ gland.
Mucous secreting
Submandibular is ______ gland.
mixed (serous and mucous)
Parotid gland is ____ gland.
Serous (watery secretion) responsible for amylase
All of the minor salivary glands secrete mucous except _______.
Von Ebners
Minor salivary glands harbor _____.
lymphocytes
Minor salivary glands contribute ____% of saliva
5-10%
What is the function of von ebners gland?
- Involved with taste
- Rinses ducts of circumvallate and foliate papillae.
What are the 2 types of Acinar cells of the Salivon?
Serous cells (enzymes) Mucous Cells (mucin)
The Acinus is made up of ___ and ____.
Acinar cells and Myoepithelial cells
What make up the Salivon?
Acinus
Intercalated ducts
Striated Ducts
Excretory ducts
What is the composition of saliva?
- Water = 99.5%
- Inorganic Salts = Potassium, chloride, bicarbonate.
- Organic components
What are the organic components of Acinar cell origin (in saliva)?
- Amylase
- Lipase
- Mucoproteins
- Proline-rich proteins
- Tyrosine-rich proteins
What are the Nonacinar cell organic components of saliva?
- Lysozyme
- Immunoglobin
- Growth Factors
- Regulatory peptides
pH of saliva is highly buffered to _____.
6.7-7.4
What is the primary mechanism that accounts for most salivary secretion?
- H2O follows NaCl
1. Intracellular Na+ is kept low and intracellular K+ is kept high
2. Intracellular Cl- is kept high.
3. In unstimulated cells, Ca2+ levels are low and Ca2+ activated K+ and Cl-channels are closed.
4. Upon stimulation Ca2+ opens and the Cl- and K+ channels.
5. Na+ leaks through tight junctions to follow Cl-.
The Acinar region is freely permeable to ______.
H2O
The duct portion is _______ to H20.
Impermeable
Describe the Primary Secretions….
Primary Secretions:
- Acinar region freely permeable to water
- Electrolyte composition unaffected by flow rate
- Plasma like composition (isotonic)
Decscribe the Secondary Secretions.
Secondary secretions:
- Ductal region impermeable to water.
- Electrolyte composition strongly affected by flow rate
- Lowe rate = HIGH K and High rate = High Na
- Hypotonic in compostion
What is the most abundant protein is saliva?
Mucin (Adds viscosity and is carbohydrate rich) protein) *Produced by sublingual and submandibular glands.
_____ is predominately produced by the parotid gland.
Amylase (salivary protein that integrates breakdown of starch)
Digestive protein, lingual lipase comes from _______.
Von Ebners gland
What are the Immune associated proteins in saliva?
- Muramidase = lyse muramic acid in the cell wall of bacteria.
- Lacoferrin
- Immunoglobulins
What do the Calcium binding proteins in saliva do?
Promote mineralization of the enamel.
What are the growth factor proteins in saliva?
EGF (stimulates gastric growth) and NGF (Sympatheic NS)
How are proteins secreted?
Via protein sorting sites
What two divisions of the NS control salivation?
Autonomic NS subdivisons:
Sympathetic
Parasympathetic
What is the key neurotransmitter of parasymp. salvation?
Acetylcholine
What is the Key neurotransmitter of sympathetic salvation?
Norepinephrine
What are some other neurotransmitter that are involved in salvation?
Substance P
Neuropeptide Y
What are the Salivary reflexes?
Basically your salivary glands have mechanoreceptors that can also be stimulated
Parasympathetic stimulation of salivary gland release _____ into the acinar cell and results in a _____ secretion.
ACh
Watery-plasma like secretion
Describe the “Big Picture” steps in saliva secretion….
- Muscarinic or Alpha adrenergic receptor activation (Mostly done by ACh on muscarinics, but some Norepine. on Alpha adrenergic receptors)
- Intracellular calcium release
- Increase luminal Cl- concentration
- Intercellular sodium follow
- Water follows NaCl
- Protein secretion by PKA mediated Exocytosis
Norepinehrine results in ______ saliva.
Protein rich saliva, via PKA mediate exocytosis
*Beta Adrenergic receptor.
How can saliva be used as a diagnostic fluid?
Used to diagnose:
- infection
- endocrine disorders
- Cardiovascular
- Cancer
What happens when salvia goes bad?
- You get a thick tongue that hurts.
- Teeth demineralize (caries)
- Increase bacterial load = periodontitis, gingivitis.
Why does xerostomia occur?
- Age
- Drugs (side effects)
- Autoimmune disorder (Sjorgren syndrome)
- Radiation Tx
How do you treat xerostomia?
Stimulate muscarinic receptors with Pilocarpine (a Ach Agonists) * This doesn’t work very well though, so you are better off treating the symptoms
