salivary gland Flashcards
what is the structural composition of salivary glands
- compound = made up of multiple secretory units with their tubules entering a main duct
- tubulo-acinar structures
what are the primary functional units of a salivary gland
1) combination of tubules
2) globe like secretory units called acini
what is the duct system
- modifies and transports the saliva to be finally secreted onto a free oral mucosal surface
- hence salivary glands are described as exocrine
describe the structure of a gland
- lobe on outside
- capsule
- septum (connective tissue between lobes containing blood vessels, nerves and collecting ducts)
- secretory units -> acinus -> intercalated duct -> striated duct -> collecting duct
what are salivary glands classified by
THEIR SECRETION
1) mucous (viscous) - mucin rich contains proteins linked to greater amnts of carbs
2) serous (watery) - protein rich
3) mixed
what are the 3 major salivary glands from biggest to smallest and their secretions
1) parotid = 100% serous
2) submandibular = 10:1 ratio s:m
3) sublingual = 10:1 ration m:s
what are the minor salivary glands
- smallest, discreet, contained throughout oral mucosa
- contained within
1) mucosa of lip (m)
2) cheek (m)
3) hard + soft palate (m)
4) tongue (s)
why is the tongue the exception to minor salivary glands being mucous
- GLANDS OF VON EBNER (in dorsum of tongue beneath circumvirate papillae) are minor serous producing
what is the composition of saliva
99% H2O
small amnt of inorganic and organic compounds
list the 7 functions of saliva
1) digestive
2) antibacterial
3) mineral protection
4) lubricant
5) taste
6) hormone production
7) maintenance of oral homeostasis
explain the digestive function of saliva
salivary amylase ptyalin
explain the antibacterial function of saliva
- lysozyme, histatins, antimicrobial peptides, antibodies
- combat bacterial colonisation by bacterial killing or inhibiting binding of bacteria to oral surfaces
- mucosal immunity by immunoglobulins (mainly IgA)
explain the mineral protection function of saliva
buffer HCO3 + mineral ions Ca + P
- mineral ions aid remin
- bicarbonate ions buffer plaque acid
- maintains integrity of enamel
explain the lubricant function of saliva
imp in
1) protection of oral mucosa (via mucin production)
2) food bolus formation
3) swallowing and speech
explain the taste function of saliva
- amylase / ptyalin brings substances into solution so they can be tasted
- solubisation of food substances so they can be transported to taste buds
explain the hormone production function of saliva
taste buds
explain the maintenance of oral homeostasis function of saliva
- by various proteins, enzymes, growth factors
- imp in wound healing
what system controls salivary secretion
AUTONOMIC NERVOUS SYSTEM