Salivation Flashcards
Saliva as compared to serum values
Na
K
Cl
HCO3
Solution is
Dec
Inc
Dec
Inc
Hypotonic- absorbing more than putting in
Salivary glands secrete
.5-1L day
Slightly acidic at rest, basic at high flow rates
Saliva
Parotid
Submandibular
Sublignual
Buccal
Always hypotonic, less hypotonic at high flow rates
P- serous secretion and amylase (Ptyalin), 25% total secretion @ rest, 70% with stimulation (food)
Subm- serous and mucus, 70% at rest
Subl- mucus. 5%
B- mucus
Functions of saliva
Lubrication
Amylase aids in carb digestion (starch)- active pH 4-11
Oral hygiene (breaks down bacteria)
Taste
Contains RNAse/DNAse/peroxidase/lysozymes/Kallikrein
Saliva formation
2 stage model Primary secretion (acinar cells) is an ultrafiltrate of plasma, subsequently modified (by duct cells)
Saliva formation steps
Faster flow rates
1- requires a very high blood flow (portal circulation around ducts/acini)
2- acinar cells secrete salivary alpha-amylase and lingual lipase plus serous fluid (plasma like)
3- duct cells modify ion conc
Absorb Na/Cl, secrete K/HCO3
Other mechs occur (Aldo inc Na/K exchange)
Faster flow rates lead to less complete modification
Regulation
No classic GI hormone control, but Na conc is affected by aldo and ADH
ANS central reflexes- cortical/tactile stimuli/taste/smell
project to NTS and sup/inf salivatory nuclei
PNS= 7/9 CN send strong stimulation (primarily cholinegic)
SNS- inc salivation, mostly mucous, B adrenergic
Cellular mechanisms
Inc cAMP (strong stimulation of amylase secretion) or IP3/Ca(volume)
Dysfunction
Siallorhea
Xerostomia
Inflamed salivary glands
Pain
Excessive salivation, rabies
Dry mouth
Mumps
Mechanoreceptors in capsule responding to stretch
Smell/taste/sound projects to
Results in
Salivatory nucles of medulla
to PNS
Otic Ganglion/Submandibular ganglion
to Parotid/Subm gland
Inc salivary secretion via effects on acinar secretion/VD
