salivary

2. Functions of intercalated ducts:
• Convey the saliva from the terminal
secretory units to the striated ducts
• Cells of the proximal portion of these ducts
show indication of secretory function
• Capable of reabsorping proteins from the
lumen
• Represent a reserve of UMC which offer a
degree of regeneration
• Antibacterial protein ( Lactoferrin) has been
localized in these ducts.

3. b-Striated duct:
1- Lined by a single layer of columnar
cells with numerous apical microvilli.
2- Central nucleus.
3-Eosinophillic cytoplasm.
4- Prominent Basal striations due to :
a- membrane infolding
b-numerous elongated mitochondria
5- a-Cell organells …………..,
b-junctional complex (apically)&
desmosomes (laterally)
2
a
b
4
Apical end

4. Functions of the striated ducts:
1- Modify the secretion passing through them
(how ?)
A-Their lining cells do not reabsorb water
B-Actively reabsorb Na, Cl ions
C-Secret K ,HCO3 ions
Thus the secretion is changed from
ISOTONIC
With high Na,CL
and low K ions
HYPOTONIC
with low Na , Cl ions
and high K ions

5. 2-Iodine concentration takes place in this
duct helping in Iodine metabolism.
3-The lining cells contains:
• Kallikrein (affect H2O & electrolyte
balance)
• Amylase ( transferred by these ducts
from the serum to saliva)
• Lysosomes ( have antibacterial effect)

6. c-Excretory duct and main duct
1- Interlobular ducts lined
by tall columnar cells.
2- Interlobar ducts are lined
by pseudostratified
columnar epithelium with
goblet cells.
3- Main duct is lined by
stratified squamous
epithelium
1 2
3
Goblet cell

7. Function of the excretory ducts:
• Covey the secretion to the oral cavity
• Reabsorb Na, Cl & secrete K, HCO3
The ductal reabsorption of Na, Cl
exceeds
secretion of K, HCO3………leading to
HYPOTONIC saliva

8. 1
DUCT
MAIN EXCRE.DUCT EXCRETORY DUCT STRIATED DUCT INTERCALATED
Modification of
primary
secretion.
Passive conduit
Sec. Granules.
Minor contribution
in secretion
Reabsorbed
from primary
secretion .
Secreted
in primary
secretion.
Secreted.
Reabsorbed
FUNCTIONS OF SALVARY GLAND DUCTS
Acinus

9. B- Connective tissue.
Form a capsule surrounding the gland from which
septa or strands extend to subdivide the gland into
major lobes. Lobes are further subdivided into
lobules. Lobe
The intercalated and
Striated ducts are
considered
intralobular ducts.
The excretory ducts
on the other hand are
considered
interlobular ducts.

10. 1 – Cells:
a-Fixed C.T. cells b-Migrating cells
Fibroblasts, Plasma cells, Macrophages
Mast, and Fat cells. Leukocytes.
2- Fibers:
Reticular & collagen.
3- Ground substances:
a-Glycoproteins b-proteoglcans
B- Connective tissue elements

11. 4- Blood supply:
Follow the excretory duct to form:
a-Dense capillary network till striated duct.
b-Less capillary loops around Intercalated Duct
&Secretory portion.
c- Arteriovenous anastomoses.
5- Nerves:
*Unmyelinated axons surrounded by cytoplasmic
processes of the shwann cells.
*Follow the course of the vessels forming plexus in
the C.T. near the Secretory portion.

12. Types of human salivary glands
1- Major salivary glands:
A- Parotid. b- sumandibular. c-sublingual.
2-Minor salivary glands:
A-Labial &buccal gland. B- Palatine gland.
C- Glossopalatine gland. D-Lingual gland.

13. 1- Major salivary glands:
A- Parotid gland

14. *It’s the largest salivary gland.
*Its superficial portion lies subcutaneously.
*Its deeper portion lies behind the ramus.
*Pure serous in adult& mixed in infant &old age
*Main duct Stensen’s duct.
*C.T. capsule surrounds it & sends septa to divide
the gland into lobes &lobules.
*Secretes 25-30% of saliva.
*Intercalated duct longer than in the other glands.
A- Parotid gland

16. b- Submandibular gland

17. b- Submandibular gland
*Next in size.
*Lies in the submandibular triangle behind &
below the free border of the mylohyoid M. with
small extension above it.
*Mixed predominatly serous.
*Main duct Wharton’s duct.
*Extensive C.T. capsule.
*Secretes 60-70%of secretion.
*Straited ducts longer than those of the parotid.

19. C-Sublingual gland

20. C-Sublingual gland
*Smallest.
*Lies between floor of the mouth &mylohyoid
muscle.
*The major gland is mixed predominantly mucous.
*The minor gland are pure mucous.
*Major-Bartholin’s duct opens near sumand.duct.
*Minor-Rivinus ducts (8-10) open in sublingual
fold.
*Poorly defined C.T. capsule with prominent C.T.
septa.
*Secretes 5%or less of saliva.

22. Comparison between major salivary glands
Sublingual
Mixed
Predominant
Mucous
Minor
subling.
(pure
mucous)
Submandibular
Mixed
predominant
serous
Parotid
Pure
serous
in adult
Mixed in
infants
& old
age
The type of
the gland
Bartholin
(Rivinus 8-
12)
Wharton
Stenson
Main ducts

23. sublingual
submandibular
parotid
Poorly
developed
Well
developed
Well
developed
capsule
Poorly
developed
Shorter than
those in parotid
Long
branched
I.c.duct
Poorly
developed
(lacking
basal st.)
longer
Numerous
Well dev.
St . duct
mandibular
nerve
Mandibular
nerve
mandibular
nerve
Sensory
innv.
Sublingual
&submental
artery
Facial & lingual
artery
Ext. carotid
artery
Blood
supply

24. Sympathatic innervation….from superior cervical ganglion
by post-ganglionic fibers (for all glands)
Parasympathetic innervation:
For parotid gland…..from glossopharyngeal nerve
which reach the gland through otic ganglion & auriculo –
temperal n.
For sub-mand.&sub-ling…..from facial nerve which reach
the gland through submandibular ganglion

25. 2-Minor salivary glands:
- Distributed throughout the submucosa.
- Small, discrete masses.
- Lack distinct capsule
- Posses numerous short ducts that open
directly in the oral cavity.
- Occurance of focal accumulation of
lymphocytes around their duct wall.
- Secrete high amount of IgA concentration.
-Secrete 7% of saliva.

26. A-Labial &buccal gland.
-More glands are present in the lower lip.
- They are present on the surface of the
orbicularis oris muscle while in the buccal
mucosa they are present on the surface &
inbetween the buccinator muscle.
-Mixed gland but ultrastructurally they only
show mucous cells.
- Buccal glands duct open in the third molar
area & are known as molar gland.

27. Minor mucous glands

28. B- Palatine gland&
C- Glossopalatine gland.
Palatine:
Pure mucous.
In Hard Palate 250 Soft Palate 100
Uvula12
Glossopalatine:
Pure mucous.
Found in the isthmus region.

29. Gland of hard palate

30. D-Lingual gland
Weber gland
Blandin-Nuhn SG
von Ebner S G

31. 1-Blandin- Nuhn
Ant. part mucous, Post. Part- mixed
Open in the ventral surface
2-Von Ebner (VE) Pure serous
under circumvallate& folliate papillae
Wash the trough, dissolve the food,
Contain digestive enzymes ( amylase &
lipase ), and protective enzymes
(Peroxidase & lysozymes ).
3-Weber Pure mucous
Open in the lingual crypt.
D-Lingual gland

33. Age changes of salivary glands
1- Fatty degenerative change.
2- Atrophy of a part or a whole terminal portion
with its replacement by fibrous tissue (Fibrosis).
3-Accumulation of lymphocytes in the stroma.
4- in the salivary secretion which leads to xerstomia.
5- xerstomia leads to difficulty in eating&swallowing
as well as in dental caries.
6- Oncocyte cells in number & may form neoplasm
in old people.

34. Young age
Old age
Fatty degenerative change.

35. Saliva
A-Definition:
Saliva is a complex fluid produced by
the salivary glands, whose important
role is maintaining the well being of the
mouth.
For ex. patients with deficiency of
salivary secretion experience difficulty
in eating, speaking& swallowing &
become prone to mucosal infections &
rampant caries.

38. 1-Protective functions: It provides a washing action
that clears harmful substances in the oral cavity.
Functions of saliva:
2-Buffering action: Mucin lubricates oral tissues and
forms a barrier against microbial products.
Saliva maintains neutral pH in the oral cavity which
prevents demineralization of enamel that would occur due
to acids produced by sugar metabolizing bacteria.

39. 3-Maintenance of tooth integrity:
*Saliva is rich in calcium and phosphate ions that leads to
post eruptive maturation of enamel which increases their
hardness and resistance to demineralization.
*It helps to protect the teeth from dental caries.
*The cleansing action of saliva and the presence of high
molecular weight glycoproteins which aggregate specific
strains of microorganisms reduce the concentration of
substrates and number of bacteria in the oral cavity.

40. 4-Defense: (antimicrobial action) (bacteriostatic)
*Salivary IgA is an important factor in oral immune defense,
together with salivary agglutinins (glycoproteins)
*IgA causes clumping of certain microorganisms thus
preventing them from adhering to oral and dental surfaces.
*Other components namely histatins, lysozyme, lactoferrin
and peroxidase inhibit bacterial growth.

41. 5-Taste functions
• * It enables the pleasurable sensations
of food to be experienced.
• *It permits the recognition of noxious
substances.
• *Contains protein Gustin necessary for
growth & maturation of taste buds

42. 6-Digestive functions:
• Saliva has digestive enzymes as
*amylase :
carbohyderate…………Glucose &
Maltose
*Lingual lipase produced by von Ebner
Triglycerides diglycerides & fatty acids

43. 7-Tissue repair
• Experimentally;
Clotting time …….accelerated when
saliva is mixed with blood
Rate of wound contraction…..increased
in presence of saliva as it contains
epidermal growth factor produced by
submandibular s.g in mice.

44. Thank you& Good luck