Salivary Gland Structure Flashcards
Where does the primary secretion of saliva start
acini
in what order does saliva drain from acini to the oral cavity
acini/acinus
intercalated ducts
striated ducts
secretory ducts
what type of cells make up an acinus
pyramidal cells which are polarised (nucleus is at the periphery)
what are the 2/3 types of acinus?
serous
mucous
serous demilunes
what type of acini are predominantly found in the parotid gland?
what type of saliva does this secrete?
serous acini
secretes watery serous saliva
what type of acini are predominantly found in the sublingual gland?
what type of saliva does this secrete
mucous acini
secretes thick mucous like saliva (mucin)
what type of acini are found in the submandibular gland?
mix of mucous (20%) and serous (80%)
what are serous demilunes?
serous cells on top of a mucous acinus
how do serous acinar cells appear?
prominent nuclei in basal
basophilic Rough ER - attracts purple staining (dark appearance)
granular appearance
how do mucous acinar cells appear?
pale cytoplasm - filled with granules of mucin (which dont pick up the stain or are removed during the process of the section)
flatted nucleus at basal aspect (due to cell being so filled with mucin)
what cells can be found around acini and intercalated ducts?
myoepithelial cells
what is being increasingly thought about serous demilunes
that they may be artifactual due to the way the section has been processed
what are the functions of myoepithelial cells?
they have contractile elements
acini - they squeeze the acinus, which may assist in secretion
intercalated ducts - regulate duct lumen diameter
describe the appearance of intercalated ducts
small cuboidal cells with a large central nucleus
difficult to see in routine wax sections
what salivary gland are striated ducts not seen in?
sublingual glands
where does modification of saliva take place
striated ducts
striated duct cells have a central nucleus due to what reason
massive basal membrane folding
why do striated ducts have basal membrane folding
to increase surface area for exchange - which can potentially cause a big change in the composition of saliva
what cell organelles show that striated ducts are very active?
lots of mitochondria present
how do secretory (collecting) ducts change as they get closer to the oral cavity
they become larger in diameter
they go from pseudostratified (one layer of cells) to stratified
eventually merges with stratified oral epithelium
