salivary glands Flashcards
what is seen in patients with sever hyposalivation
increased incidence of caries
hyposalivation
reduced salivary flow (2/3 typical)
symptoms of decreased salivary loss
Xerostomia Mucosal changes Enamel erosion Increased caries Difficulty swallowing changes in tatse
subjective feeling of dry mouth
Xerostomia
Genic cause of dry mouth
Rare
systemic disease for dry mouth
Mups
Sjogren’s
Diabetes mellitus
HIV
Medication causing dry mouth
Anti-cholinergic, diuretics, antidepressants, antihistamines, antihypertensives
what is largelt responsible for prevalence of dry mouth in elderly patients
age kinda, but mostly medication
mdical treatment that cuases dry mouth
Head and neck radiotherapy
efects of head and neck radiotherapy on salivation
rapid(days) and long lasting
initial effect of radiotherapy on salivation
reduced gland function
later effects of head and neck radiotherapy
cell death, primarily acinar cells
how do we try and spare salivary function from radiotherapy
newer radiation therapies for specific target tumor site
therapies to aid in saliva production
genetic modification of remaining salivary tissue
Stem cell
stem cel use for salivary flow
clauster of saliva secreting cells (Acinus-like) grown invitro from stem cells in the parotid gland
mangement of hyposalivation
frequent dental evaluation and prophylaxis due to prevalence of complication
artifical saliva
salivary stimulants
what must be checked for hyposalivation patients
caries
oral lesions
oral candidias
what are some artificial salivas
mucopolysaccharide (MouthKote) Glycerate polymer (Oral balance Hydroxyethylcellose( salivart, oralube, xerolube)
salivary stimulants
sugarless candies, chewing gum
secretatgogus (agonist for cholinergic muscarinic receptors)
Major functions of saliva
Protection Buffering Tooth integrity antimicrobial tissue repair Digestion taste
how does the saliva protect
Lubrication and protective barrier (mucins)
clearance of bacteria and sugar
how does the saliva buffer
Neutralization of acids and pH maintenanec (bicarbonate)
how does the saliva aid in tooth integrity
Enamel maturation via calcium binding proteins (proline rich proteins and statherin)
what does the saliva has as an antimicrobia
Lysozyme, peroxidase, defensins, histatins
Iga (agglutination of microorganisms, anti-viral)
what does the saliva do for tissue repair
growth factors
what does the saliva do for digestion
lubrication, swallowing: mucins
Enzyme digestions: amylase, lipase
what does the saliva do for taste
Dissolves stimuli for transport to taste recetpors: water
what kind of gland is the salivary gland
Exocrine glands
unstimulated saliva rate
.2-.4 per min
how much saliva is in the mouth
1ml as a thin film that coats everything
stimulated saliva rate
2-5 per min
saliva flow during sleep
decreases during sleep
what are the major saliva glands
Parotid gland
submandibular
sublingual
what are the minal saliva glands
Von ebners gland
Labial, palatal, buccal, lingual
what innervates the parotid
IX
what inneravtes the submandibular
VII
what innervates the sublingual
VII
what innerates von ebner glands
IX
what does the parotid gland make
serous (watery), amylase
what does the submandibular make
mixed, mostly serous
what does the sublingual make
Mixed, mostly serous
what does von ebner gland make
Lingual lipase
what does labial, palatal, buccal, lingual
Mucins
saliva flow percentatge from the major glands
60: parotid
25: submandibular
7-8: sublingual
what does the parotid have to have saliva leave
stensons duct
largest salivary gland
Paroid
GR for parotid
14-28
GR for submandibular
10-15 GR
what does the submandibular have to have saliva leave
Wharton’s duct
GR for sublinual
2 GR
ducts of sublingual
Rivinius and Bartholin’s duct
the functional component of the salivary gland
Parenchyma
the supporting components of the salivary gland
Stroma (Connective tissue
ducts going to the eventual outside of gland
Intercalated
Striated
Collection
curoudns the salivary gland
Capsule
infoldings of the salivary gland
Septa
what does the septa do
Divides gland into lobes (major larger divisions) and lobules (minor smaller divisions)
what does the stroma contain
Fibroblasts (produce collagen) Blood vessels (supply parenchyma) Nerve fibers (supply parenchuma) Plasma cells (Secrete antibodies)change in the stroma over age fat cells
how do fat cells change with age
increases
what makes up the parenchyma
Acini (secretory endpieces) and ducts
where are serous acini found
PArotid gland
where are mucous acini found
minor glands
where are mixed acini found
submandibular and sublingual
when is the parotid initiated
4-6 week IU
where does the submandibular initiate
week 6 IU (end)
when does the sublingual and minor glands initiate
week 8-12
when does acinar cell mature
during last 2 months of gestation
how long does salivary gland growth continue
2 years postnatal(especillay acinar cells)
parenchuma orgin of salivary glands
parotid: ecotderm
submandibular: ectoderm
minor: endoderm
strom origin of salivary glands
Neural crest
stesp ofsalivary gland development
Protrusion of epithelial cells in mesenchyme
BUd formation
branching Morphogenesis
branching morphogenesis continues, cavitation (forming ducts)
terminal differntaitionL maturation of ducts then acinar (secretory) cells
what type of interaction is important for salivary gland development
heterotypic tissue interactions
examples of heterotypic tissue interactions for salivary glands
Epithelial-mesenchymal signalling
Neural-epithelial signaling
do salivary gland development pathways repleaste
yes, and similar as those used in tooth development
what part of acini are H2O permiable
acinar cells are H2O permiable and Duct cells are not H2O permiable
roll of Acinar cells
Primary secretsion
rollof duct cells
Secondary secretion
what do the Acini cells secrete
water, ions, (Na+ and Cl-) proteins
tonicity of acinar cells
Isotonic
action of duct cells
resob NA and Cl
secrete bicarbonate
secrete proteins
tonicity of duct cells
Hypotonic
How does the sympa system reach the salivary gends
starts in teh intermediolateral nuclasus
sympa trunk
superior cervical ganglion
all glands
parasympa for salivary glands
Salivary nucleus
VII: palate and nsoe galnds, sublingusal, submandibular
IX: parotid, von ebner
sympathetic control of salivary secetion
NE binds to beta-adrenergic receptor (GPCD)
adentlate cycalse, cAMP, pka
PKA phosphorylates secretory granules
Granules released
saliva secreted due to sympathetic
Protein-rich
viscous
scant
saliva secereted from parasympathetic
watery
copious secretion
how does Parasympa control saliva
Ach binds to muscarinic receptors (GPCR)
PLC, IP3, Ca++
Ca++ opens Cl- channels
Cl- flows to lumen to created osmotic/electric gradient
Na+ and water follow by paracellular and transcellular
how is Cl- kept in the salivary galnd cells
maintained at a high intracellular concentration using an energy-requiring pump
what mkes up the major part of generalized acini
Cluster of Acinar cells surrounding a central lumen
spaces between acinar cells in generalzied acini
Intercellular spaces
junctions between acinar cells in generalized acini
Tight
desmosomes
gap
othercells of generalized acini
Myopeithelial cells
what surrounds generalized acini
Basal lamina
morphology of serous acinar cell
Pyramidal shape resting on basal lamina with short irregular microvilla
what does Serous acinar cell look like
like apolarized protein secreting cells
what does a serous acinar cell secrete
enzymes and glycoproteins - packaged in secretory granules
protein machinery of serous cells
well defined
Rer
Golgi apparatus
Secretory Granules
Morphology of mucous cells
Cuboidal to columnar
Oval nuclei pressed toward the base
how are mucous cells arranged around the lumen
arranged in tubules around a larger central lumen
what do mucous cells secrete
mucins (high molecular wt, heavily glycosylated glycoprotein, for lubrication)
how do mucous cell stain
secretory granules pale staining
cytoplasm pale
serous demilune is found where
present in mixed glands
what is a serous demilune
mucous acinus, topped by a cluster of serous cells
what does a serous demilune result from
Conventional fixation
what happens when a serous demilune is rapidly frozen
serous and mucous cells side by side
mucous nuclei also not compressed
do mucous cells always stain pale
no depends on the stain
where are myoepithelial cells found
surrounding the acini and intercalated ducts but within the basal laimina
features of myoeptihelial cells
processes that curround multiple secretory cells in an acinus and intercalcated ducts
what cells are myoeptihelial cells similar to
similar to smooth muscle but derived from epithelium
what are the processes of myoepithelial celsl filled with
actin and soluble myosin
innneravtion of myoepithelial cells
neuraly innervated
roll of myoeptihelial cells
facilitate movement of saliva into the ductal system
what ducts do major salivary glands have
all 3 types
what ducts do minor salivary glands have
intercalated sometimes observed
Striated absent
exretory main type
the smallest duct
Intercalated duct
how many acini drain into an intercalated duct
several acini drin into intercalated duct
Morphology of intercalated duct
cuboidal
cental nucleus
what does the intercalated duct secrete
a few proteins
size/activity of striated duct
longer and more active duct
why is stuff reabsorbed in a striated duct
converts isotonic (primary saliva) into hypotonic (secondary saliva)
how does striated duct absorb
against concentration gradient using ATP
what is secreted in the straited duct
proteins
bicarbonatetd
Morphology of the striated duct cell
Columnar polarized short microvilli numerous infolding of basolateral membrane (striations) prominent mitochondria
purpose of excretory duct
Plumbing
what makes up the excretory duct
series of connecting ducts becoming progressivel wider
epithelium of excretory duct
changes from single epithelial layer to pseudostratified epithelium
eventually keratinized
where is the excretory duct found
located in connective tissue
lumen shape of the excretory duct
irregularly shaped
morphology of excreoty duct cells
irrgularly positioned nuclei
pseudostratied
where are exretory ducts found
in the septa
what surrounds the excretory duct
fibroblasts
what else might be found in the excretory duct
goblet cells(screting mucous)