1. Najran University
Faculty of Dentistry
Dr. Mutaz Ali Hassan

2.  Salivary glands are compound, tubuloacinar,
merocrine, exocrine glands the ducts of which
open into the oral cavity.

3.  Classification of salivary glands:
 According to the size:
1. Major salivary glands.
2. Minor salivary glands.
 According to the type of secretion:
1. Serous secreting.
2. Mucous secreting.
3. Mixed.

4.  Major salivary Glands
 Parotid: largest,
anterior to ear,
serous,25% of total
saliva.
 Submandibular:
Intermediate, angle of
mandible,60% of total
saliva.
 Sublingual: Smallest,
anterior floor of mouth,
5% of total saliva.

5.  Minor salivary
Glands
 Labial (lips) – mixed
 Buccal (cheeks) -
mixed
 Palatine - mucous
 Lingual:
1. Anterior – mixed
2. Middle – serous
3. Posterior – mucous.

6.  Saliva secretion is a reflux function result from
afferent stimulation of salivary centers (by
various stimuli e.g. taste and mastication).

7. 1. Water (99%): washing and cleaning of tooth
surfaces and mucosa, solubilizing of food for
tasting and food bolus formation.
2. Mucin: lubricant, formation of salivary
pellicle.
3. Minerals: (Ca ++) remineralization of enamel,
(bicarbonate ions) buffering.

8. 4. Antimicrobial: Ig A, lysozyme, lactoferrin.
5. Digestion: Amylase digest carbohydrate.
6. Tissue repair: short bleeding time of oral tissues,
epidermal growth factor (wound healing).

9.  Primary saliva: is hypertonic secreted by
acini and intercalated ducts.
 Modified saliva: is hypotonic due to
reabsorption of Na+ and Cl- and secretion of
K+ and bicarbonate, by striated ducts.

10.  Resting saliva: 0.1-0.3 ml/min.
 Stimulated saliva: 1-3 ml/min.
 The total daily amount: 500-750 ml/day.

11.  Glandular secretory tissue:
1. Secretory cells (acini and secretory ducts).
2. Excretory ducts (collecting and main ducts).
 Myoepithelial cells: ( contractile cells)
 Supporting connective tissue stroma:
1. Fibroblasts ( produce collagen).
2. Fat cells.
3. Plasma cells (produce immunoglobulins Ig A).

12.  Salivary Acinus (acini):
 Functional unit of the salivary gland.
 A cluster of pyramidal cells (serous or mucous
or both) that secretes into a lumen.

13.  Serous cells:
 Pyramidal cells with
basophilic granular
cytoplasm and basally
located nuclei.
 Produce proteins and
glycoproteins.

14.  Mucous cells:
 Elongated pyramidal
cells with pale
vacuolated cytoplasm
basally located nuclei.
 Produce low proteins
high in carbohydrates
(mucin).

15.  Mixed acini:
 with serous and
mucous cells.
 Serous demilune.

16.  Intercalated duct:
 Lined by cuboidal
epithelial cells.
 Secretion of protein
and electrolyte
exchange.

17.  Striated Ducts:
 Lined by columnar
cells with eosinophilic
abundant cytoplasm.
 Microvilli in the
luminal surface and
striation in basal ends.
 Reabsorption of Na+
and Cl-
 Secretion of K+ and
bicarbonate.

18.  Star-shape cells with
long processes.
 Found around acini
and intercalated
ducts.
 Contractile cells that
squeeze to empty
acini.

19.  Duct system consists of:
1. Secretory portion (intercalated and striated
ducts) which lies within lobules (intralobular)
2. Excretory portion (collecting and main ducts)
which lies in the connective tissue septa between
lobules (interlobular duct).

20.  Acinar cells drain directly
into intercalated ducts.
 Intercalated ducts opens
into striated ducts.
 Both intercalated and
striated are intralobular
duct system, which means
they are present inside the
lobules.
 The remaining excretory
ducts are interlobular
which means it is located
within the connective
tissue septa.

21.  Collecting ducts:
 Columnar cells and basal
cells.
 The basal cells are stem cells
responsible for regeneration.
 Transport saliva to main
ducts.
 Main ducts:
 Stratified columnar
epithelium, near surface
becomes stratified squamous
epithelium .
 Transport saliva to oral
cavity.

22.  Surrounds major
glands forming CT
capsule that extends
into body of the gland
lobe and lobules
called septa.
 It carries the blood
and nerve supply to
the secretory
elements.

23.  Parasympathetic and sympathetic impulses.
 Parasympathetic impulses: evoke fluid to be
excreted, cause exocytosis, induce contraction
of myoepithelial cells (sympathetic too) and
cause vasodilatation.
 beta-adrenergic receptors that induce protein
secretion.

24.  Fibrosis and fatty
degenerative changes
 Presence of oncocytes
(eosinophilic cells
containing many
mitochondria)

25.  Obstruction.
 Role of drugs.
 Systemic disorders.
 Bacterial or viral infections.
 Therapeutic radiation.
 Formation of plaque and calculus.