salivary glands Flashcards
Saliva is involved to some degree in all of the
following functions:
Speech Mastication Taste Swallowing Digestion
saliva in digestion
salivary amylase
saliva and taste
gustin: protein thought to be necessary for growth and maturation of taste buds.
saliva function in protection
Lubrication protects lining mucosa from noxious stimuli,
bacterial toxins, and minor trauma
Washing action to rid mouth of non-adherent bacteria
Clearance of sugars from mouth
saliva buffering function
prevents?
buffers?
protein component?
Prevents potential pathogenic bacteria from colonizing the
mouth (most require an acidic pH)
Buffering of microbial acids (bicarbonate & phosphate ions)
Sialin: a protein that raises pH of dental plaque after exposure
to fermentable carbohydrates
saliva antimicrobial function/components
Lysozyme: hydrolyzes bacterial cell walls
Lactoferrin: binds free iron and thereby deprives bacteria of an essential nutrient
Salivary IgA: causes bacterial clumping (agglutination)
saliva function in tooth integrity
Calcium and phosphate ions facilitate mineralization of
tooth surface
saliva and soft tissue repair
Epithelial growth factor
Clotting factor
development of the salivary glands
dictated by?
form?
Ectomesenchymal cells dictate differentiation of oral epithelium which, in turn, proliferates and grows into the underlying mesenchyme.
The epithelial buds undergo histodifferentiation and morphodifferentiation to form assemblies of:
Alveoli that develop into acinar cells
Epithelial cords that develop into ducts
stages of salivary gland development in order, important GFs
Induction of oral epithelium by underlying ectomesenchyme
Growth of the epithelial cord
Initiation of epithelial cord branching
Repetitive branching and lobule formation
Canalization of the presumptive ducts
Cytodifferentiation to become acinar cells, myoepithelial cells,
and ductal cells
• FGF (fibroblast growth factor)
• EGF (epidermal growth factor)
developmental “equation” of salivary glands
see attatched
when do the major salivary glands develop
The parotid and submandibular glands begin to form during the
6th week of embryonic development with the sublingual gland
initiating development during the 8th week.
when do minor salivary glands develop
The minor salivary glands begin to form by the 10th week of
embryonic development.
Hierarchy of ducts starting at the level of the secreting unit (acinus):
Intercellular canaliculus Intercalated duct Striated duct Excretory duct (a.k.a. collecting duct) Terminal excretory duct
intercellular caniculi
between acinar cells
possess villi for resorbtion of water