Salivary Glands Flashcards
What are the two types of salivary glands
And how much saliva do each type account for?
Extrinsic 90% and intrinsic 10%
What salivary glands are extrinsic
Parotid
Submandibular
Sublingual
What makes a salivary gland extrinsic
Outside of the oral cavity
What salivary glands are intrinsic
Buccal
Labial
Palatine
What is the difference between the frequency of secretion of intrinsic and extrinsic glands
Intrinsic - secreting saliva at a constant rate
Extrinsic - secreted saliva based on a stimulus
How does saliva from extrinsic salivary glands enter the oral cavity?
Through ducts
Where does the parotid duct empty into
Around the second [maxilllary]molar
Where does the submandibular [Warton’s] duct empty
Around base of the tongue called the lingual frenulum
How many sublingual ducts are there and where do they empty
10-20 ducts
Base of the tongue
What are two types of cells that form the extrinsic salivary glands
Serous
Mucus
What type of cells is the parotid gland primarily made of
Serous
What is the cell composition of submandibular gland
Mix of serous and mucus
What type of cells is the sublingual gland primarily made of
Mucus
[does have a few serous]
Where are the superior and inferior salivatory nucleuses found
In the brainstem around the pons
What nerve innervates both the submandibular and the sublingual glands
The facial nerve
Where does the stimulatory action potential originate from for salivation from the submandibular and the sublingual glads
Superior salivatory nucleus
What cranial nerve and nerve innervates the parotid gland
Glossopharyngeal
Lesser perfusal nerve
Where does the stimulatory action potential originate from for salivation from the parotid gland
Inferior salivatory nucleus
What receptors/ things are responsible for stimulation of the superior and inferior salivatory nucleus?
Sight, smell, thought
Chemoreceptors eg. Acidic
Mechanoreceptors eg. Chewing
How is salivation controlled by the parasympathetic nervous system?
Cranial nerves 7 and 9
Act to increase the volume for saliva that is water and electrolyte rich
How does the sympathetic nervous system affect salivation
Wants saliva that is protein rich so is thicker
What spinal vertebrae does the superior cervical ganglion come from
About t1 to t4 ish
What neurotransmitter does the parasympathetic nervous system release to stimulate salivation
Acetylcholine
What neurotransmitter does the sympathetic nervous system release to stimulate salivation
Noradrenaline
What is the name for the process when water moves into the lumen by squeezing through gaps in cells
Paracellular transport
How does water get from the acinar cell into the gland?
Aquaporin 5
How does water get into the acinar cells
Aquaporin 3
How do chloride ions get out of the acinar cells and into the gland?
CFTR protein channels
What are the constituents of the primary secretion ?
Na+ K+ Cl- HCO3- H2O
True/ false
The primary secretion is NOT isotonic
False
What happens to the concentration of Na+ and Cl- in the secondary secretion
Decrease
How does the concentrations of Na+ and Cl- change in the secondary secretion
Decreases
Na+ exchanged for a proton
Cl- exchanged for bicarbonate
What is the difference between the make up of the primary vs secondary secretion
Primary = isotonic (in relation to blood plasma). [H2O] = [Na+] + [Cl-]
Secondary = hypotonic (in relation to blood plasma). [H2O] > [Na+] + [Cl-]
What receptors does acetyl choline attach to
M3
How does acetylcholine increase the volume of h20 and electrolyte secretion from acinar cells?
Ach binds to M3 and stimulates Gq
Gq usually bound to GDP but binds to GTP when stimulated
Stimulates PLC which breaks down PIP2 into DAG and IP3
IP3 stimulates increase in Ca2+ levels inside the cell
DAG activates kinases which phosphorylates channels that increases secretion of water and Na+ K+ Cl- ect
What receptors does norepinephrine bind to
Beta receptors
How does noradrenaline promote thicker saliva production
Binds to beta receptors
Activates g stimulatory protein which is usually bound to GDP but binds to GTP when activated
Stimulates adenyl cyclase
ATP -> cAMP which stimulates PKA
PKA stimulates exocytosis of protein rich granules
Enzymes and proteins -> lumen area
Mucin and salivary amylase
How does norepinephrine affect blood flow around acinar cells
Vasoconstriction
Decreases blood flow
Decreases water and electrolyte secretion as they come from the blood
What are the functions of saliva
Oral hygiene
Antimicrobial
Chemical digestion
Hydrate oral cavity and food
Increase taste of substances
Decreases incidence of cavities
What parts of saliva make it anti microbial
IgA
Cystatins
Histatins
Lysozymes
What constituent of the saliva helps maintain enamel on teeth
Proline rich proteins
Where does IgA bind on salivary gland cells
Polymeric immunoglobulin receptor on the apical membrane of acinar cells
