salivary glands anatomy, histology, development, disorders, treatment diagnosis

1. SALIVARY
GLAND
UPAMA SISHAN 1

2. 2
Glands classification
Salivary gland classification
Anatomy of salivary glands
Development of salivary glands
Histology
Difference between serous & mucous acinus
Imaging
Disorders
references

3. 3
EXOCRINE: duct present
ENDOCRINE: no duct
secrete hormones directly into the blood.
GLANDS OF THE BODY:

4. 4
TYPES OF EXOCRINE GLANDS:

5. MODES OF SECRETION

6. CLASSIFICATION OF THE SALIVARY
GLANDS:
SALIVARY GLANDS – EXOCRINE
(COMPOUND TUBULOACINAR)
- MEROCRINE GLAND
BASED ON THE SIZE:
MAJOR - extraoral
MINOR - intraoral
BASED ON THE NATURE OF SECRETION:
SEROUS
MUCOUS
MIXED
6

7. 7

8. 8

9. MINOR SALIVARY GLANDS:
9

10. 10
• Serous secretion
• Solubilze substances -
stimulate the taste cells
around circumvallate
papillae
LINGUAL GLANDS:
GLANDS OF BLANDIN & NUHN:
• Mucous
• Ventral aspect of tongue
WEBERS GLAND:
• Pure mucous - posteriorly

11.  Largest
 Wt – 15g
 a three sided pyramid
 4 surfaces & 3 borders.
 With apex directed
downwards.
 Accessory parotid – a part of
forward extension, often
detached.
PAROTID GLAND
11

12. PAROTID CAPSULE:
12

13. 1. Superficial Temporal
vessels.
2. Auriculotemporal n.
3. Cartilaginous part of
External Auditory Meatus.
4. Temporal branch of Facial
n.
SUPERIOR SURFACE:
13
RELATIONS:

14. 1. Ramus of the mandible.
2. Masseter muscle.
3. Medial pterygoid muscle
ANTERO-MEDIAL SURFACE
14

15. 1. Mastoid process
2. Sternocleidomastoid
3. Posterior belly of Digastric
4. Styloid process and the
muscle & ligaments
attached to it.
5. Internal carotid artery &
Internal jugular vein.
POSTERO-MEDIAL SURFACE
15

16. 1. Cervical branch of Facial n.
2. Retromandibular vein.
3. Posterior belly of digastric.
4. External Carotid artery.
APEX
16

17. 1. Skin and superficial fascia.
2. Great Auricular nerve.
3. Parotid lymph nodes.
SUPERFICIAL SURFACE
17

18. • Zygomatic branch of Facial
n.
• Transverse Facial artery.
• Buccal branch of Facial n.
• Accessory Parotid gland.
• Parotid duct.
• Mandibular branch of
Facial n.
ANTERIOR BORDER
18

19. STRUCTURES WITHIN PAROTID
GLAND
1. External carotid A
2. Retromandibular
Vein
3. Facial Nerve
4. Parotid lymph
nodes Superficial temporal A
Maxillary A
P.Auricular A
Superficial temporal V
Maxillary V
Post auricular V
External jugular Common Facial V
Facial Nerve
temporal
buccal
mandibular
cervical
zygomatic
Zygomaticotemporal
Cervicofacial
19

20. PAROTID DUCT:
 Stensons duct
 Thick walled
 5 cm long
 Emerges from middle of anterior border
It opens into the vestibule of mouth opposite to the 2nd upper
Molar.
20

21. BLOOD SUPPLY:
External carotid artery
VENOUS DRAINAGE:
Into external jugular vein
LYMPHATIC
DRAINAGE:
Parotid nodes
Upper deep cervical nodes
21
NERVE SUPPLY:
Sensory: auriculotemporal n
for gland, great auricular nerve
for the capsule.
Sympathetic: plexus around the
middle meningeal artery.
Parasympathetic: reach the
gland through
auriculotemporal nerve.

22. SUBMANDIBULAR
GLAND:
- Anterior part of digastric
triangle
- J-shaped
- Walnut size
- 3- surfaces – lateral,
medial, inferior
- Covered by 2 layers of
deep cervical fascia.
22

23. PARTS
1. Superficial part
2. Deep part
3. Submandibular duct
Superficial part
Deep part
Submandibular duct
23

24. RELATIONS
1. Inferior surface: skin, superficial fascia (containing
platysma, cervical branch of facial n, facial vein,
Lymph Nodes) & deep fascia.
2. Lateral surface:
submandibular fossa,
facial artery,
insertion of medial
pterygoid.
3.Medial surface:
mylohyoid,hyoglossus,
styloglossus, lingual n,
hypoglossal n,
submandibular
ganglion. 24

25. SUPERFICIAL PART
Wedge shaped, extending:
Posteriorly: to the angle of mandible.
Superiorly: to mylohyoid line of mandible.
Inferiorly: it overlaps the 2 bellies of digastric m
25

26. DEEP PART
• Small part lying deep to mylohyoid
• Superficial to hyoglossus
• Between lingual nerve above & hypoglossal nerve
below
Mylohyoid
Lingual n.
26

27. SUBMANDIBULAR DUCT:
Wharton’s duct
Thin walled
5cm long
Emerges at the anterior end of the deep part of the
gland.
Runs forward on hyoglossus
Open at floor of the mouth, on the summit of sublingual
papilla, at the side of the frenulum of tongue.
27

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29. 29
BLOOD SUPPLY
Facial artery
VENOUS DRAINAGE
Common facial & lingual vein
LYMPHATIC DRAINAGE:
Submandibular lymph nodes

30. NERVE SUPPLY:
Supplied by branches of submandibular ganglion –
sensory fibres from lingual nerve.
secretomotor fibers.
vasomotor sympathetic fibres from the plexus on the facial a
30

31. SUBLINGUAL SALIVARY GLAND
Smallest of the three glands
 3-4 gm
Almond shape
RELATIONS
SUPERIOR: mylohyoid
INFERIOR: mucosa of floor of mouth
MEDIAL: sublingual fossa
LATERAL: genioglossus
31

32. 32
SUBLINGUAL DUCT:
Bartholins duct
Duct of rivinus
About 15 ducts
BLOOD SUPPLY:
• Lingual & submental arteries
• Venous drainage corresponds to the
arteries
NERVE SUPPLY:
Same as that of the submandibular gland

33. 33

34. DEVELOPMENT OF SALIVARY GLANDS:
PAROTID :6TH WEEK,
ECTODERMAL
SUBMANDIBULAR ;
6TH OR 7TH WEEK
ENDODERMAL
8TH WEEK
ENDODERMAL IN
ORIGIN 34

35. BUD STAGE
CORD STAGE
INITIATION OF BRANCHING
REPITATIVE BRANCHING & LOBULE
FORMATION
DUCT CANALIZATION
CYTODIFFERENCIATION
35
STAGES

36. INDUCTION OF ORAL
EPITHELIUM
BY UNDERLYING MESENCHYME
FORMATION & GROWTH OF THE
EPITHELIAL CORD
36

37. INITIATION OF BRANCHING
REPETITIVE BRANCHING OF THE
EPTHELIAL CORD & LOBULE
FORMATION:
37

38. CANALIZATION OF PRESUMPTIVE
DUCTS
CYTODIFFERENCIATION
38

39. 39
BRANCHING MORPHOGENESIS:
Clefts develop in bud
two or more new buds form
Succesive generations of buds
Requires::
Epithelial mesenchymal interactions
Signaling molecules: Fibroblast growth factor protein family
Sonic hedgehog
Transforming growth factor β & their receptors.

40. BRANCHING OF THE EPITHELIAL CORD:
.
Type III Collagen: Accumalates at cleft points , critical for branching to occur(active
branching).
Type IV & I Collagen: For the maintenance & support of established
branches(stabilization).
Collagen selective degradation & synthesis(after branching).
Differential contraction of actin filaments at the basal & apical ends of the
epithelial cells.
40
ROLE OF COLLAGEN:

41. 41

42. HISTOLOGY OF SALIVARY GLANDS:
TERMINAL END STRUCTURE:
CELL TYPES:
THREE PRIMARY CELLS
 MUCOUS
 SEROUS
 MYOEPITHELIAL
DUCTAL SYSTEM:
CLASSIFICATION BASED ON
ITS LOCATION:
(1)INTRALOBULAR DUCTS
- INTERCALATED
- STRIATED
(2) INTERLOBULAR
- EXCRETORY DUCT
42

43. DIAGRAM SHOWING ACINI AND DUCT
SYSTEM IN SALIVARY GLANDS:
43

44. DISTINGUISHING CHARACTERISTICS OF THE
MAJOR SALIVARY GLANDS:
44
Parotid gland:
• A purely serous gland
• Interlobular connective tissue contains a large number of
fat cells which increases with age.
• Fat cells – totally vacuolated appearance.
• Serous cells are deeply stained with H & E staining.
• Intralobular ducts are prominent.

45. 45
Submandibular gland:
• A mixed type of gland.
• Majority of the acini are serous.
• More striated and fewer intercalated ducts.
• Acini are either purely serous or are mixed tubules-
smaller serous & larger mucous cells.
• Serous demilunes are evident.

46. 46
Sublingual gland:
• Most of the acini are mucous-secreing.
• There are few purely serous acini in humans.
• Few mixed acini with serous demilunes.
• Intralobular duct system are poorly developed.
• Intercalated ducts are virtually absent.
• Absence of striations in the columnar cells lining the
intralobular ducts.
• Sublingual saliva has a much higher concentration of
sodium than the other major salivary glands.

47. DISTINGUISHING CHARACTERISTICS OF THE
MINOR SALIVARY GLANDS:
47
• Produce serous & mucous secretions.
• Secretory activity appears to be continuous rather than
in response to specific stimuli.
• 10% of total salivary secretion.
• But approx 70% of mucous secretion.
• Empty the secretory products into oral cavity through
numerous small ducts.
• Are polystomatic (multiple main excretory ducts).
• Ducts of minor salivary gland (lips), tend to form
cysts(mucocele).

48. MUCOUS CELL:
- Synthesis, storage & secretion of the secretory product.
- Secretory droplets – larger than serous
- Larger than serous cell
- Secretory end piece - tubular
SECRETION:
- little or no enzymatic activity
- lubrication, protection of oral tissues.
METHOD OF EXPELLING THE SECRETORY
PRODUCT:
(1)EXOCYTOSIS
(2)Several droplets fuse to form larger droplets –
escape through breaks in the plasma
membrane 48

49. 49

50. 50

51. 51
ALCIAN BLUE:
PAS

52. 52
MUCICARMINE:

53. SEROUS
- Devote 80% of its capacity – production of ZYMOGEN
granules.
- Secretory end piece - spherical
SECRETION:
-enzymatic
- shows acid phosphatase, esterases, glucoronidase,
glucosidase & galactosidase activity.
METHOD OF EXPELLING THE SECRETION:
• membrane of the granule fuse with plasma membrane at
the lumen
• prevents loss of cytoplasm.
53

54. 54

55. 55

56. 56

57. 57
INTERCELLULAR JUNCTIONS:
TIGHT JUNCTION (ZONULA OCCLUDENS)
maintain cell surface domains
regulate passage of material from the lumen to intercellular spaces
ADHERING JUNCTION (ZONULA ADHERENS)
DESMOSOME (MACULA ADHERENS)
GAP JUNCTION:
allow passage of small molecules between cells(ions, metabolites etc
HEMIDESMOSOMES:
Secretory cells to the basal lamina & to the connective tissue.
These junctions coordinate activity of all the cells within an end piece.
Holds adjacent
cells together

58. 58

59. 59
Parameter serous acinus mucous acinus
Size of acinus small large
Lumen narrow wide
No: of cells 8 - 12 ≥ 8
Size of cell smaller larger
Shape of nucleus round oval / flat
Position of n basal third basal
Supranuclear zymogen granules mucinogen granules
Cytoplasm (electron dense) (electron lucent)

60. 60
Parameter serous acinus mucous acinus
Cells lateral not clear clear
boundaries
Secretory end piece spherical tubular
Apical microvilli present absent
Amylase activity less more

61. SEROUS DEMILUNES:
Mucous end pieces in the major salivary glands & some
minor salivary glands have serous cell associated with them
in the form of a demilune or cresent covering the mucous
cells at the end of the tubule.
RECENT STUDIES:
- is an artifact traditional methods of preparing
samples. Formaldehyde.
- samples preserved by quick-freezing in liquid nitrogen &
fixed with osmium tetraoxide in acetone, no demilunes are
found.
61

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63. 63

64. MYOEPITHELIAL CELLS
64
• BASKET CELL: a basket cradling the secretory cell.
• Associated with the secretory end pieces & intercalated
ducts.
• Located between basal lamina & the secretory cells(
attached by desmosomes)
• Numerous branching processes extend from the cell
body to embrace the end pieces
• Ultrastructurally - similar smooth muscle cells .
• Stellate shape – secretory cells.
• Fusiform shape – intercalated ducts.

65. 65
FUNCTIONS OF MYOEPITHELIAL CELLS:
Accelerate initiate outflow of saliva from acini.
Reduce luminal volume, may shorten & widen ducts
helping to maintain their patency.
Contribute to secretory pressure in the acini or duct.
Support underlying parenchyma & decrease back
permeation of fluid.
Help salivary flow to overcome decrease in the
peripheral resistance of the ducts.

66. 66
RECENT STUDIES:
- Signaling the secretory cells
- Protecting the salivary gland tissues
- Produce a no: of proteins( tumor suppressor activity) –
barrier against invasive epithelial neoplasm.

67. 67

68. INTERCALATED DUCT:
68
Primary saliva first pass through
Modify saliva
Contribute to the macromolecular components of saliva
stored in secretory granules.(lyzozyme, lactoferrin)
prominent in salivary glands having a watery secretion
(parotid).
Diameter is small, lumina is larger than that of the end
pieces.
Undifferenciated cells present.

69. 69

70. 70

71. STRIATED DUCT:
71
 Receive saliva from intercalated ducts.
 Site of electrolyte resorption(sodium & chloride)
 Secretion of pottasium and bicarbonates
 Secretory product: isotonic hypotonic fluid.
 Ductal cells: kallikrein & epidermal growth factor

72. 72

73. 73

74. EXCRETORY DUCT:
74
 Located in the connective tissue septa between the
lobules of the gland(interlobular duct).
 Larger in diameter than striated ducts.
 Pseudostratified epithelium columnar cells.

75. 75

76. 76

77. CONNECTIVE TISSUE
Consists of surrounding capsule and septa
capsule: demarcate gland from adjacent tissue.
septa: divide gland into lobes & lobules.
Cells: Fibroblasts,macrophages, dentritic cells, mast
cells,plasma cells, adipose cells, granulocytes, lymphocytes.
Extracellular matrix: Glycoproteins and proteoglycans
Collagen & elastic fibers.

78. 78
FUNCTION OF CONNECTIVE TISSUE CELLS:
• A structural support.
• Assists in the maintenance of homeostasis in the oral cavity.
• In inflammatory processes associated with pathology.

79. GROWTH FACTORS AND PEPTIDES SECREATED BY THE
SALIVARY GLANDS:
79
EPIDERMAL GROWTH FACTORS (EGF):
Found in human salivary glands.(intercalated ducts of the
parotid gland
Influences tooth eruption, epidermal keratinization & cell
proliferation & differenciation throughout the body.
Absorbed from the saliva by cells lining the oral cavity,
esophagus, stomach & small intestine.
GLUCOGON LIKE PROTEIN:
 Human submandibular salivary gland
ATRIAL NATRIURETIC PEPTIDE
 Localized in the salivary glands
 It could regulate fluid balance

80. INNERVATION OF THE SALIVARY GLANDS
80

81. 81
INTRAEPITHELIAL INNERVATION:
SUBEPITHELIAL INNERVATION:

82. SALIVARY GLAND IMAGING
• Plain film radiography
• Sialography
• Computed tomography
• Radionuclide imaging
• Ultrasonography
• Magnetic resonance imaging

83. 83
SIALOGRAPHY:
• evaluate of the
functional integrity
of the salivary glands
• case of obstructions
• evaluate the ductal
pattern
• facial swellings, to
rule out salivary
gland pathology
• intra-
glandular neoplasms

84. CT scan
Inflammatory diseases, calculi, neoplastic
diseases

85. 85
MRI
Less obscuration for dental amalgam
Superior contrast resolution
Better mass characterisation
Enhanced MRI: perineural disease
if abscess is suspected
determine the exact location and extent of a
tumor

86. DISORDERS OF SALIVARY GLAND
Functional disorders
- increased secretion.
- decreased secretion.
Developmental disorders
Obstructive disorders
Inflammatory and infectious disorders
Immunological disorders
Neoplastic diseases

87. DEVELOPMENTAL DISORDERS
• Aplasia (agenesis)
• Atresia
• Aberrant salivary gland. (stafne’s cyst)
• Diverticuli
• Darier’s disease (duct dilation with periodic stricture)

88. 88
SALIVARY
STONES:
Sialolithiasis
• Common in
submandibular salivary
duct
• Calcium phosphate in
the form of
hydroxyapatite is the
main mineral
component.
• Larger stones induces
sialoadenitis.
OBSTRUCTIVE DISORDERS:

89. 89
MUCOCELE
• (1) Extravasation mucocele
• (2) Retention mucocele

90. 90
RANULA:

91. Systemic conditions with salivary gland
involvement
Infectious disorders:
• Actinomycosis
• Granulomatous disease
• Cmv infections
• Hepatits
• HIV

92. Metabolic disorders
• Sjogren’ syndrome
• Thyroid disease
• Graulomatous disease
• Alcoholism
• Malnutrition
• Eating disorders
• Diabetes (uncontrollred)

93. SJOGRENS SYNDROME
Dry eyes
Dry mouth

94. HISTOLOGICAL CLASSIFICATION OF
SALIVARY GLAND TUMOURS
WHO (1991)
• Pleomorphic adenoma
• Myoepithelioma
• Basal cell adenoma
• Warthins tumour
• Oncocytoma
• Canalicular adenoma
• Sebaceous adenoma
• Monomorphic adenoma
• Ductal papilloma
- inverted ductal papilloma
- intraductal papilloma
- sialadenoma papilliferum
• Cystadenoma
- papillary cystadenoma
- mucinous cystadenoma
1. ADENOMA

95. • Acinic cell carcinoma
• Mucoepidermoid carcinoma
• Adenoid cystic carcinoma
• Polymorphous low grade
adenosarcoma
• Epithelial- myoepithelial
carcinoma
• Basal cell adenocarcinoma
• Sebaceous carcinoma
• Papillary cystadenocarcinoma
• Mucinous adenocarcinoma
• Oncocytic carcinoma
• Salivary cell carcinoma
• Adenocarcinoma
• Malignant myoepithelioma
• Carcinoma in
pleomorphic adenoma
• Squamous cell carcinoma
• Small cell carcinoma
• Undifferenciated
carcinoma
• Other carcinomas
2. CARCINOMAS

96. 96
3. NONEPITHELIAL TUMOURS
4. MALIGNANT LYMPHOMAS
5. SECONDARY TUMOURS
6. UNCLASSIFIED TUMOURS
7. TUMOR LIKE LESIONS
- sialadenosis
- oncocytosis
- necrotizing sialometaplasia
- benign lymphoepithelial lesion
- salivary gland cysts
- chronic sclerosing sialadenitis of submandibular gland
- cystic lymphoid hyperplasia in AIDS

97. 97
SYNDROMES ASSOCIATED WITH SALIVARY
GLAND DISEASES:
 Hemifacial microsomia
 LADD snydrome
 Treacher collins syndrome
 Sjogren’s syndrome
 Felty’s syndrome
 Aglossia- adactylia syndrome
 Heerfordt’s syndrome

98. EFFECTS OF AGING:
• decrease in salivary flow
• acinar atrophy accompanied
by fibrosis
• replacement of the secretory
tissue with adipose tissue.
• structural alterations in the
ducts including intraductal
deposits.
• appearance of oncocytes,
enlarged, inactive secretory
cells with pycnotic nuclei
98

99. 99
REFERENCES:
• Oral development and histology
James Avery, third edition
• Human anatomy
B D Chaurasia, fifth edition
• Theory and practice of histological techniques
John D Bancroft
sixth edition
• Oral histology
Ten Cates
eighth edition
• Oral histology & embryology
Orbans
thirteeth edition

100. 100
• Textbook of Oral Pathology
Shafers
Seventh edition
• Oral bioscience
Ferguson
• Salivary Gland Imaging
RSNA Refresher Course (November 29, 2012)
Bronwyn E. Hamilton, MD
• Salivary gland diseases
Margaret M. Grisius, philip c. fox

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