what is the main duct for parotid called?
stensen’s duct
what is the main duct for the submandibular called?
wharton’s duct
function of saliva?
- lubrication
- digestion
- solubilisation
- moistness
- protection
what does proline rich proteins do?
- contains several repeats of short proline rich sequence
- inactivate tannins to a greater extend compared to dietary proteins which reduce fecal nitrogen loss
- contain non specific nitrogen and non essential amino acid
describe the digestion function of saliva?
- alpha amylase initiation of starch digestion
- ligual lipase which initiation of lipid digestion
- R-protein (haptocorrin) which helps with vitamin B12 absorption
how does lysozyme in saliva protect?
act on the cell wall of certain bacteria and cause lysis and death
how does thiocyanate in saliva protect?
thiocyanate will oxidise to form oxidised derivatives which are highly toxic to bacterial systems
list of 8 things that helps with oral and dental health in the saliva?
- lysozyme
- thiocyanate
- immunoglobulins
- wash and neutralise food
- alkaline pH of the saliva
- binding pathogen
- mucins
is xerostomia a disease?
no
what causes xerostomia?
- sjogren syndrome
- nerve or/and gland damage
- drug therapy
what is the basal rate of secretion during sleep?
0.05 ml/min
what is the rate of secretion during awake?
0.5 ml/min
treatment for xerostomia?
- stimulate residual saliva
- artificial saliva
describe the blood supply at the salivary glands?
- portal system
- flow pass the duct then the acinus
- substances reabsorbed from the duct are transported to capillaries surrounding the acinus by efferent arteriole
describe components of primary saliva secretion
- ultrafiltrate of plasma to which some components synthesized by acinar cells
- almost isotonic to plasma
- mucin glycoprotein secretion
- proline rich protein secretion
- IgA secretion
describe process of primary acinar fluid secretion?
- sodium go down the gradient into the cell and potassium and chloride goes in the same direction
- sodium move out of the cell and potassium is taken in
- chloride move down the apical channel as it builds up in the cell
- chloride move down the apical channel down the concentration gradient
- chloride is a negative ion and will draw sodium ions
- sodium will draw water into apical
- M3 and acetylcholine will increase the intracellular calcium through activation of protein kianses
which type of chloride channel is in the primary acinar fluid secretion?
calcium activated chloride channel
describe secondary saliva secretion?
- as it flows past the duct it will undergo secondary modification by secretory and striated duct cells
- sodium and chloride are extracted from saliva
- potassium are added to saliva
- sodium and potassium are exchanged through an active mechanism
- more sodium is extracted than potassium added
- lysozyme secretion
- bicarbonate is secreted
- duct epithelium has low permeability to water
- secondary saliva becomes more hypotonic
describe secondary ductal modification?
- lysozyme secretion
- potassium secretion
- bicarbonate secretion
- chloride reabsorption
- sodium reabsorption
what is the difference from primary to secondary secretions when unstimulated?
- alot of reabsorbtion of sodium
- secretion of potassium
- bicarbonate is reabsorbed
- chloride is reabsorbed
- total ions for unstimulated is low
what happens when secondary is stimulated?
- fluid pass through duct faster
- less time to modify it so the composition is in between primary and secondary unstimulated except for bicarbonate
- secretion of bicarbonate because stimulated duct cells therefore higher bicarbonate levels
describe ductal modification for sodium?
- ENaC move sodium from higher concentration to low concentration into the cell
- sodium can also move in through the sodium hydrogen exchanger into the cell
describe ductal modification for chloride?
- chloride is negatively charged and will move into the cell with sodium
describe ductal modification for bicarbonate?
- on apical membrane there is CFTR which transports chloride to lumen out of the cell
- chloride comes back into the cell by chloride/bicarbonate exchanger
- cause bicarbonate into the lumen
- when stimulated, CFTR become more active and allow more chloride to be recycled which increase bicarbonate secretion
