Salivary Gland Structure

Question 1

Where does the primary secretion of saliva start

Answer 1

acini

Question 2

in what order does saliva drain from acini to the oral cavity

Answer 2

acini/acinus
intercalated ducts
striated ducts
secretory ducts

Question 3

what type of cells make up an acinus

Answer 3

pyramidal cells which are polarised (nucleus is at the periphery)

Question 4

what are the 2/3 types of acinus?

Answer 4

serous
mucous
serous demilunes

Question 5

what type of acini are predominantly found in the parotid gland?
what type of saliva does this secrete?

Answer 5

serous acini
secretes watery serous saliva

Question 6

what type of acini are predominantly found in the sublingual gland?
what type of saliva does this secrete

Answer 6

mucous acini
secretes thick mucous like saliva (mucin)

Question 7

what type of acini are found in the submandibular gland?

Answer 7

mix of mucous (20%) and serous (80%)

Question 8

what are serous demilunes?

Answer 8

serous cells on top of a mucous acinus

Question 9

how do serous acinar cells appear?

Answer 9

prominent nuclei in basal
basophilic Rough ER - attracts purple staining (dark appearance)
granular appearance

Question 10

how do mucous acinar cells appear?

Answer 10

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)

Question 11

what cells can be found around acini and intercalated ducts?

Answer 11

myoepithelial cells

Question 12

what is being increasingly thought about serous demilunes

Answer 12

that they may be artifactual due to the way the section has been processed

Question 13

what are the functions of myoepithelial cells?

Answer 13

they have contractile elements
acini - they squeeze the acinus, which may assist in secretion
intercalated ducts - regulate duct lumen diameter

Question 14

describe the appearance of intercalated ducts

Answer 14

small cuboidal cells with a large central nucleus
difficult to see in routine wax sections

Question 15

what salivary gland are striated ducts not seen in?

Answer 15

sublingual glands

Question 16

where does modification of saliva take place

Answer 16

striated ducts

Question 17

striated duct cells have a central nucleus due to what reason

Answer 17

massive basal membrane folding

Question 18

why do striated ducts have basal membrane folding

Answer 18

to increase surface area for exchange - which can potentially cause a big change in the composition of saliva

Question 19

what cell organelles show that striated ducts are very active?

Answer 19

lots of mitochondria present

Question 20

how do secretory (collecting) ducts change as they get closer to the oral cavity

Answer 20

they become larger in diameter
they go from pseudostratified (one layer of cells) to stratified
eventually merges with stratified oral epithelium