Oral mucosa

classification of oral mucosa

1.  

32(
هههه ههه
هههههه
هههههه

2. 2
BYBY
DR. Fawzy DarweeshDR. Fawzy Darweesh
Assistant professor of Oral BiologyAssistant professor of Oral Biology
Faculty of DentistryFaculty of Dentistry
Mansoura UniversityMansoura University

3. Definition:

Is the moist lining of the oral cavity.
At the lips it is continuous with the
skin.
At the pharynx it is continuous with
the moist mucosa lining the rest of
the gut.

4. Protection
Function: Secretion
Sensory
Thermal regulation

5. FunctionsFunctions

1. Protection1. Protection
It protects deeper tissues from It protects deeper tissues from
mechanical forces, surface abrasions, mechanical forces, surface abrasions,
and microorganisms.and microorganisms.

6. 2. Secretion 2. Secretion
Saliva-produced by the salivary glands Saliva-produced by the salivary glands
which maintains the surface moist.which maintains the surface moist.

7. 3. Sensation 3. Sensation
By receptors (respond to temp., touch, By receptors (respond to temp., touch,
thirst, and pain).thirst, and pain).
Reflex (swallowing, gagging, and Reflex (swallowing, gagging, and
salivating) are initiated by the receptors. salivating) are initiated by the receptors.
Tongue has taste buds.Tongue has taste buds.

8. 4. Thermal regulation (dog)4. Thermal regulation (dog)
Through panting, so evaporation of water Through panting, so evaporation of water
from the surface mucosa control the animal from the surface mucosa control the animal
temperature.temperature.

9. The oral cavity consists of two areas:The oral cavity consists of two areas:
1. 1. An outer vestibule An outer vestibule (bounded by the lips (bounded by the lips
and cheeks) .and cheeks) .
2. 2. Oral cavity proper Oral cavity proper (separated from the (separated from the
vestibule by the alveolus bearing the teeth vestibule by the alveolus bearing the teeth
and gingiva) .and gingiva) .

10. Three main types of mucosa :Three main types of mucosa :
1. 1. MasticatoryMasticatory e.g. gingiva and hard palate. e.g. gingiva and hard palate.
(amounting to (amounting to 25%25% of the total area) of the total area)
2. 2. LiningLining e.g. inferior surface of the tong., e.g. inferior surface of the tong.,
labial mucosa, buccal mucosa, floor of labial mucosa, buccal mucosa, floor of
the mouth, vestibular fornix, alveolar the mouth, vestibular fornix, alveolar
mucosa, and soft palate. mucosa, and soft palate.
(amounting to (amounting to 60%60% of the total area) of the total area)
3. 3. SpecializedSpecialized e.g. dorsum of the tongue e.g. dorsum of the tongue
and taste buds.and taste buds.
(amounting (amounting 15%15% of the total area). of the total area).

11. Masticatory
Mucosa
Specialized
Mucosa
Lining Mucosa = gray shading

12. ORAL MUCOSAORAL MUCOSA
MASTICATORY
LINING
SPECIALIZED
GINGIVA, HARD PALATE DORSUM OF TONGUE
LIPS , CHEEKS,
SOFT PALATE,
VENTRAL SURFACE
OF TONGUE
ALVEOLAR MUCOSA,
VESTIBULAR FORNIX
FLOOR OF MOUTH
LOOSELY ATTACHED FIRMLY ATTACHED

13. Component Tissues and General Consideration:Component Tissues and General Consideration:
Two main tissue components: Two main tissue components:
I. Oral epithelium (stratified squamous).I. Oral epithelium (stratified squamous).
II. Lamina propria (C.T. layer).II. Lamina propria (C.T. layer).
The interface between both is irregular. The interface between both is irregular.
(C.T. papillae interdigitate with epith. (C.T. papillae interdigitate with epith.
Rete pegs) (epithelial ridges).Rete pegs) (epithelial ridges).
(Submucosa may or may not be present(

14. ORAL MUCOSAORAL MUCOSA
Basal cell layer
Prickle cell layer
Granular cell layer
Cornified cell layer
 basal
 intermediate
 superficial
Lamina propriaLamina propria
Stratified squamous
epithelium
Keratinized Non-
keratinized:
•orthoortho-keratin.
•parapara-keratin.
Papillary
layer
Reticular
layer
glands
or
fat cells
&
B.Vs.+nerves
May
or
may not
be
present
Oral epitheliumOral epithelium SubmucosaSubmucosa
Basement
membrane

15. Main tissue components of the oral mucosa

16. The interface is termed the The interface is termed the basementbasement
membranemembrane..

It contains glycosaminoglycans (GAG), It contains glycosaminoglycans (GAG),
proteoglycan, and anchoring fibrils.proteoglycan, and anchoring fibrils.

EM: basal lamina.EM: basal lamina.

17. I. Oral Epithelium (st. squ. epith.)I. Oral Epithelium (st. squ. epith.)
It maintains its structural integrity by It maintains its structural integrity by
continuous cell renewal (mitotic divisions) continuous cell renewal (mitotic divisions)
in the deepest layers to replace those that in the deepest layers to replace those that
are shed.are shed.

18. Thus, the cells consist of :Thus, the cells consist of :

1. A progenitor population (in the basal or 1. A progenitor population (in the basal or
parabasal area and provide new cells).parabasal area and provide new cells).
the basal cell layer and 2-3 layers of the the basal cell layer and 2-3 layers of the
spinous cells called stratum germenativum spinous cells called stratum germenativum
that capable to produce D.N.A and divides that capable to produce D.N.A and divides
by mitosis to give new cells just sufficient by mitosis to give new cells just sufficient
to match those lost by desquamation at the to match those lost by desquamation at the
surfacesurface
2. A mature population (differentiate to 2. A mature population (differentiate to
form a protective surface layer). form a protective surface layer).

19. Cell divission occurs and each daughter Cell divission occurs and each daughter
cell recycles in the proginator population cell recycles in the proginator population
or enters the maturing component.or enters the maturing component.
This is known as turnover time.This is known as turnover time.

20. For example;For example;

1. The turnover time is 41 to 57 days in the 1. The turnover time is 41 to 57 days in the
gingiva .gingiva .

2. The turnover time is 25 days in the 2. The turnover time is 25 days in the
cheek.cheek.

21. Nonkeratinized buccal epith. turns over Nonkeratinized buccal epith. turns over
faster than keratinized gingival epithelium.faster than keratinized gingival epithelium.
Cancer chemotherapeutic drugs act by Cancer chemotherapeutic drugs act by
blocking mitotic division of rapidly blocking mitotic division of rapidly
dividing cancer cells, as well as normal dividing cancer cells, as well as normal
host cells.host cells.

22. Proliferation
Cell migration
Cell loss
Mitotic
figure
Capillary
Connective tissue
B.M.
Stratum
basale
Stratum
spinosum
Stratum
granulosum
Stratum
corneum
Lamina
propria
Stratified Squamous EpitheliumStratified Squamous Epithelium

23. In general, maturation follows two main In general, maturation follows two main
patterns:patterns:

1. Keratinization .1. Keratinization .

2. Nonkeratinization.2. Nonkeratinization.

24. Keratinization Keratinization
Masticatory mucosa (hard palate and Masticatory mucosa (hard palate and
gingiva).gingiva).
Some region of specialized mucosa Some region of specialized mucosa
(dorsum of the tongue).(dorsum of the tongue).
Epithelium is inflexible and tightly bound Epithelium is inflexible and tightly bound
to lamina propria.to lamina propria.
The interface between epith. and The interface between epith. and
underlying lamina propria shows underlying lamina propria shows
numerous elongated papillae.numerous elongated papillae.

25. Keratinized epith. has 4 layers:Keratinized epith. has 4 layers:

1. The basal layer (stratum basale).1. The basal layer (stratum basale).
2. The prickle cell layer (stratum spinosum).2. The prickle cell layer (stratum spinosum).
3. The granular layer (stratum granulosum).3. The granular layer (stratum granulosum).
4. The keratinized layer (stratum corneum).4. The keratinized layer (stratum corneum).

26. Orthokeratinized oral epithelium

27. NonkeratinizationNonkeratinization
Lining mucosa. Lining mucosa.
Is thicker than keratinized epithelium (500 Is thicker than keratinized epithelium (500
um).um).
Has smooth interface with C. T. Has smooth interface with C. T.

28. The layers in nonkeratinized epithelium The layers in nonkeratinized epithelium
are:are:

1. Basal layer (stratum basale).1. Basal layer (stratum basale).
2. Intermediate layer (stratum intermedium).2. Intermediate layer (stratum intermedium).
3. Superficial layer (stratum superficiale).3. Superficial layer (stratum superficiale).

29. Epithelium
Lamina
propria
Submucosa

30. Keratinized Epithelium Nonkeratinized Epithelium
Oral Oral
epitheliumepithelium

31. Ultrastructure of the Epithelial CellsUltrastructure of the Epithelial Cells
Cells of Cells of basal layerbasal layer are the least are the least
differentiated.differentiated.

They contain: They contain:
1. Cytoplamic organelles.1. Cytoplamic organelles.
2. Desmosomes. 2. Desmosomes.
3. Tonofilaments (synthesized by ribosomes).3. Tonofilaments (synthesized by ribosomes).

32. Tonofilaments represent intracellular Tonofilaments represent intracellular
proteins known as proteins known as cytokeratinscytokeratins
(characteristic constituents of epithelial (characteristic constituents of epithelial
cells).cells).
So, these epith. cells are called So, these epith. cells are called
keratinocyteskeratinocytes. .

33. 1- Thickening of the adjacent
cell membrane.
2- A pair of attachment plaque.
3- Tonofilaments.
4- An intervening extracellular structure.
The desmosomes

34. Intercellular Junction
Desmosome
Tight junction
Gap junction

35. Adhesion between the epith. cells and C.T. Adhesion between the epith. cells and C.T.
is by is by hemidesmosomeshemidesmosomes..

36. Ultrastructure of basal lamina (EM(
Hemidesmosomes (arrowheads(
Junction between epith. and C.T.

37. Two other types of connection: Two other types of connection:
1. Gap junction. 1. Gap junction.
2. Tight junction.2. Tight junction.

38. The next layer : The next layer : prickel cell layerprickel cell layer and and
granular layergranular layer in keratinized and in keratinized and
intermediate layerintermediate layer in nonkeratinized epith. in nonkeratinized epith.

39. InIn both, granules discharge their contents both, granules discharge their contents
into the intercellular spaces, and into the intercellular spaces, and
Thickening of intracellular (inner) Thickening of intracellular (inner)
membrane of the superficial cells.membrane of the superficial cells.

40. In keratinized epith.In keratinized epith., as the cells of , as the cells of
granular layer reach the junction with granular layer reach the junction with
keratinized layer, a sudden changes occur.keratinized layer, a sudden changes occur.

41. These changes are: These changes are:
1. All the organelles with the nuclei and 1. All the organelles with the nuclei and
keratohyaline granules disappear.keratohyaline granules disappear.
2. The cells dehydrated. 2. The cells dehydrated.
3. The keratinized layer become packed 3. The keratinized layer become packed
with filaments, flattened, assume the with filaments, flattened, assume the
form of hexagonal disks (squames) .form of hexagonal disks (squames) .
This pattern of maturation is termed This pattern of maturation is termed ortho-ortho-
keratinizationkeratinization..

42. For masticatory mucosa, For masticatory mucosa,
parakeratinizationparakeratinization may occur: may occur:
1. Incomplete removal of organelles from the 1. Incomplete removal of organelles from the
cells of granular layer. cells of granular layer.
2. The nuclei remain shrunken or pyknotic. 2. The nuclei remain shrunken or pyknotic.
3. Remnants of other organelles may present 3. Remnants of other organelles may present
in the squames.in the squames.

43. Types of KeratinizationTypes of Keratinization
orthokeratinized or parakeratinized

44. In nonkeratinized epith.:In nonkeratinized epith.:
1. Increase in cell size (intermediate layer).1. Increase in cell size (intermediate layer).
2. In the superficial cell layer : 2. In the superficial cell layer :
The cells appear more flattenend.The cells appear more flattenend.
Accumulation of glycogen. Accumulation of glycogen.
The cells contain dispersed The cells contain dispersed
tonofilament. tonofilament.
The nuclei and some keratohyaline gr. The nuclei and some keratohyaline gr.
remain. remain.
Diminished no. of other cell organelles. Diminished no. of other cell organelles.
No signs of keratinization. No signs of keratinization.

45. Histological structureHistological structure::
Stratified
Squamous
epitheliumepithelium
EpitheliumEpithelium
Papillary
layer
Reticular
layer
Lamina propriaLamina propria
(C.T.)(C.T.)
SubmucosaSubmucosa

46. Nonkeratinocytes in the oral epithelium : Nonkeratinocytes in the oral epithelium :
(Not participate in the process of (Not participate in the process of
maturation) maturation)
1. Melanocytes. 1. Melanocytes.
2. Langerhan's cells. 2. Langerhan's cells.
3. Markel’s cells. 3. Markel’s cells.
4. Inflammatory cells (lymphocytes).4. Inflammatory cells (lymphocytes).
( ( They form 10% of the epith. cellsThey form 10% of the epith. cells ) )

47. Characteristics of Nonkeratinocytes in Oral Epithelium Characteristics of Nonkeratinocytes in Oral Epithelium
Cell Type Level in
Epithelium
Origin Function
Melanocyte Basal & sometimes
parabasal
Neural crest cellsMelanin synthesis
and transfer to
surrounding
keratinocytes
Langerhan's cell Predominantly
Suprabasal
Bone marrow Antigen trapping
and processing
Markel’s cell Basal Epithelial cells Tactile sensory cell

Lymphocyte Variable Blood Associtated with
inflammatory
response in oral
mucosa

48. All these cells, All these cells, except Merkel cellsexcept Merkel cells, lack , lack
desmosomal attachment to adjacent cells desmosomal attachment to adjacent cells
so that during histologic processing the so that during histologic processing the
cytoplasm shrinks around the nucleus to cytoplasm shrinks around the nucleus to
produce the produce the clear haloclear halo. .

49. Nonkeratinocytes
Clear cells
Langerhan’s cells
Melanocytes
Merkle cells
Blood cells

50. 1- Pigment cell
(Melanocyte, blast(
2- Langerhan’s cell 3- Merkel’s cell
Shape
Small body with long
slender and branched
process present in
the I.C.S of epith.
contain melanin
granules
(melanosomes(
Similar in shape.
Contain granules
(langerhan’s granules(
(Bir-beck granules(
They do
not have
long processes.
Contain small
membrane bounded
granules
LocationBasal and parabasal
layers
High level cell and may
be found at lower
levels.
Basally in
epithelium
Stain by
H&E
Not stained so called
( Clear dentritic cell (
Not stained so called
( Clear dentritic cell (
Not stained so
called
( Clear but not
dentritic cell (
Special
stain
DOPA reaction ( for
tyrosinase enzyme(
Gold chloride PAS +ve

51. Nonkeratinocytes in oral epitheliumNonkeratinocytes in oral epithelium

These cells have the following criteria:These cells have the following criteria:
1- 1- Present in both keratinized and non-kertinized Present in both keratinized and non-kertinized
epithelium.epithelium.
2- 2- Appear as clear cells by ordinary H&E stain, they Appear as clear cells by ordinary H&E stain, they
need special stains.need special stains.
3- 3- Present as scattered cells and not in sheetsPresent as scattered cells and not in sheets..
4- 4- A clear hallows around their nuclei.A clear hallows around their nuclei.
5- 5- Their cytoplasm is free from tonofilaments (except Their cytoplasm is free from tonofilaments (except
Merkel’s cells). Merkel’s cells).
6- 6- No cellular junctions.No cellular junctions.
7- 7- They do not play any role in synthesis of They do not play any role in synthesis of
keratohyaline granules or keratin.keratohyaline granules or keratin.

52. Junction of the Epth. and lamina propriaJunction of the Epth. and lamina propria

Light microscope: Basement membrane. Light microscope: Basement membrane.
(structureless band in H & E) (structureless band in H & E)
 EM: Basal lamina. EM: Basal lamina.
(lamina lucida and lamina densa + (lamina lucida and lamina densa +
anchoring fibers) anchoring fibers)

53. All the basal lamina, except its anchoring All the basal lamina, except its anchoring
fibrils, is synthesized by the epithelium.fibrils, is synthesized by the epithelium.

54. II. Lamina PropriaII. Lamina Propria

 Can be devided into 2 layers:Can be devided into 2 layers:
1. The superficial papillary layer. 1. The superficial papillary layer.
2. The deeper reticular layer.2. The deeper reticular layer.

55. The lamina propria consists of :The lamina propria consists of :
1.1.Cells Cells
•Synthetic cells (fibroblasts, fat cells)Synthetic cells (fibroblasts, fat cells)
•(UMC).(UMC).
•Inflammatory cells (lymphocytes, Inflammatory cells (lymphocytes,
plama cells, macrophages, monocytes, plama cells, macrophages, monocytes,
mast cells, and neutrophils).mast cells, and neutrophils).
2. Blood vessels. 2. Blood vessels.
3. Nerves.3. Nerves.
5. Fibers (collagen and elastic) embedded 5. Fibers (collagen and elastic) embedded
in ground substance (in ground substance (proteoglycous proteoglycous
andand glycoproteins) glycoproteins)..

56. The papillary zone may be absent in some The papillary zone may be absent in some
areas (alveolar mucosa). areas (alveolar mucosa).

The reticular zone is always present. The reticular zone is always present.
The lamina propria may attach to The lamina propria may attach to
periosteum or it may overlay the periosteum or it may overlay the
submucosa.submucosa.

57. SubmucosaSubmucosa
Consists of C.T. of varying thickness and Consists of C.T. of varying thickness and
density.density.

Attaches the MM to the underlying Attaches the MM to the underlying
structures (loose or firm).structures (loose or firm).
Thus the MM may be movable or Thus the MM may be movable or
immovable.immovable.

May be present or absentMay be present or absent . .

58.  It contains: It contains:
1. Glands. 1. Glands.
2. Blood vessels. 2. Blood vessels.
3. Nerves. 3. Nerves.
4. Adipose tissue.4. Adipose tissue.

59. Masticatory MucosaMasticatory Mucosa
The epith. is moderately thick and may be The epith. is moderately thick and may be
orthokeratinized or parakeratinized . orthokeratinized or parakeratinized .
B.M. is convoluted (numerous elongated B.M. is convoluted (numerous elongated
papillae).papillae).

60. The lamina propria is thick. The lamina propria is thick.
It covers immobile structures (e.g. palate It covers immobile structures (e.g. palate
and alveolar process).and alveolar process).
Bound firmly to the periosteum.Bound firmly to the periosteum.

61. Hard PalateHard Palate
MM is immovable.MM is immovable.

Pink in color.Pink in color.
The lamina propria is The lamina propria is thicker anteriorly thicker anteriorly
and has numerous long papillae.and has numerous long papillae.

62. Gingiva
Gingiva
Hard palate
SPECIALIZED

63. Masticatory mucosa covering the palate
Dense submucosa attatching m. m. to periosteum

64. Various regions can be distinguished Various regions can be distinguished
because of varying structures of the because of varying structures of the
submucous layer.submucous layer.

65. These regions are:These regions are:
1. Gingival region (adjacent to the teeth).1. Gingival region (adjacent to the teeth).
2. palatine raphe (extending from incisive 2. palatine raphe (extending from incisive
papilla posteriorly). papilla posteriorly).
3. Anterolateral area (fatty zone)between the 3. Anterolateral area (fatty zone)between the
raphe and gingiva. raphe and gingiva.
4. Posterolateral area (glandular zone) 4. Posterolateral area (glandular zone)
between the raphe and gingiva.between the raphe and gingiva.

66. Hard Palate Macro-anatomy
incisive
papilla
median
palatine
raphe
soft
palate
uvula
palatine
gingiva
palatine
rugae
antero-
lateral (fatty
zone(
postero-
lateral
(glandular
zone(

67. Palate : dense lamina propria with fat in some regions of the submucosa

68. Histology of Hard PalateHistology of Hard Palate
Submucosa
Fatty zone
Glandular zone
Epithelial rete pegs
are regular, tall and
numerous
Mucosa

69. The peripheral zones (The peripheral zones (palatine gingivapalatine gingiva) do ) do
not have a submucosa (identical with the not have a submucosa (identical with the
gingiva and the palatine raphe).gingiva and the palatine raphe).

70. GingivaGingiva
Surrounds the neck of the teeth and extends Surrounds the neck of the teeth and extends
to the alveolar mucosa. to the alveolar mucosa.
It is made up of It is made up of st. squ. epith. st. squ. epith. which may be which may be
orthokeratinized (15%) , nonkeratinized orthokeratinized (15%) , nonkeratinized
(10%) , or parakeratinized (75%).(10%) , or parakeratinized (75%).

71. Histology of GingivaHistology of Gingiva
Stratified squamous
keratenized epithelium
Lamina propria
Epithelial rete peg
C.T.
papilla
Tall
Numerous
Slender
Irregular
No submucosa

72. The gingiva is limited on the outer surface The gingiva is limited on the outer surface
by the by the mucogingival junction mucogingival junction which which
separates it from the alveolar mucosa. separates it from the alveolar mucosa.
Mucogingival junction
Gingiva
Alveolar mucosa
Labial mucosa

73. Alveolar mucosa
Interdental
papilla
Free ging. groove
Attached gingiva
Free gingiva

74. Mucogengival junction
(keratinized gingiva – right ; nonkeratinized mucosa – left(

75. On the inner surface of the lower jaw a line On the inner surface of the lower jaw a line
of demarcation is found between the of demarcation is found between the
gingiva and the mucosa on the floor of the gingiva and the mucosa on the floor of the
mouth.mouth.

76. On the palate the distinction between the On the palate the distinction between the
gingiva and the peripheral palatal mucosa gingiva and the peripheral palatal mucosa
is not so sharp.is not so sharp.

77. The gingival is divided into :The gingival is divided into :
1. The free gingiva.1. The free gingiva.
2. The attached gingiva. 2. The attached gingiva.
3.The interdental papilla.3.The interdental papilla.

78. Enamel
Free Gingiva
Free Gingival
Groove
Attached
Gingiva

79. Attached gingiva with thick layer of keratin
( no distinct submucosa (

81. Free gingival groove: between the free Free gingival groove: between the free
gingiva and the attached gingival (0.5 gingiva and the attached gingival (0.5 –– 1.5 1.5
mm at or apical to the botton of the mm at or apical to the botton of the
nonkeratinized gingival sulcus).nonkeratinized gingival sulcus).

82. The gingival surface appears The gingival surface appears stippledstippled (due (due
to epith. ridges and numerous collagen to epith. ridges and numerous collagen
bundles attaching the tissue to periosteum).bundles attaching the tissue to periosteum).
The gingiva appears depressed between The gingiva appears depressed between
adjacent teeth (between the eminence of adjacent teeth (between the eminence of
the socket) and form slight vertical folds the socket) and form slight vertical folds
called called interdental groovesinterdental grooves..

83. Interdental
papilla
Free gingival
groove
Interdental folds
in interdental groove
Mucogingival
junction
Alveolar
mucosa
Free gingiva
Attached
gingiva
(stippled)
Gingival
margin

84. Gingival margin
Free gingiva
attached
gingiva
Gingival
sulcus
Gingival stippling
Free
gingival
groove
Dentin
Space of
enamel
Sulcular epithelium
Junctional epithelium
cementum
dentino
gingival
fibers
Gingiva – Micro-Anatomy

85.  The interdental papillaThe interdental papilla
Triangular when viewed from the Triangular when viewed from the
vestibular aspect. vestibular aspect.
In a 3 dimensional view, it is In a 3 dimensional view, it is pyramidalpyramidal
between the ant. teeth and between the ant. teeth and tenttent shaped shaped
between post. teeth. between post. teeth.
The central part is concave (below the The central part is concave (below the
contact eara) and is called the gingival contact eara) and is called the gingival colcol
which is covered by thin which is covered by thin nonkeratinizednonkeratinized
epithepith..

86. Gingiva – Macro-Anatomy
Free gingiva
attached
gingiva
Gingival
stippling
Free
gingival
groove
pale
pink
“col region”

87. Interdental papilla and gingival ColInterdental papilla and gingival Col
Gingival col( non-
keratenized(
Contact point
Col

88.  Gingival ligaments Gingival ligaments
1. Dentogingival group .1. Dentogingival group .
2. Alveologingival group. 2. Alveologingival group.
3. Circular group. 3. Circular group.
4. Dentoperiosteal group. 4. Dentoperiosteal group.
5. Transseptal group (interdental lig.).5. Transseptal group (interdental lig.).

89. Gingival LigamentGingival Ligament
Alveolog. gr.
Dentog. gr.
Dentoperios. gr.
Circular gr.

92. Melanin pigment is present in the gingival Melanin pigment is present in the gingival
epith.epith.

Elaborated by melanocytes (basal layer).Elaborated by melanocytes (basal layer).
Can be studied by dopa reaction or silver Can be studied by dopa reaction or silver
staining techniques.staining techniques.

The number of melanocytes is constant (no The number of melanocytes is constant (no
difference in their no. in blacks or whites).difference in their no. in blacks or whites).

93. Pigmented gingiva
Attached gingiva

94. Melanin pigment

95. Gingival SulcusGingival Sulcus
Extends from the free gingival margin to Extends from the free gingival margin to
the dentogingival junction. the dentogingival junction.
The sulcular epith. is The sulcular epith. is nonkeratinizednonkeratinized..
It lacks epith. ridges.It lacks epith. ridges.

96. Gingival margin
Free gingiva
attached
gingiva
Gingival
sulcus
Gingival stippling
Free
gingival
groove
Dentin
Space of
enamel
Sulcular epithelium
Junctional epithelium
cementum
dentino
gingival
fibers
Gingiva – Micro-Anatomy

97. The sulcular epith. is continuous with the The sulcular epith. is continuous with the
gingival epith. and the attachment epith. gingival epith. and the attachment epith.
They have a continouous basal lamina.They have a continouous basal lamina.

98. • Nonkeratinized stratified
squamous epith.
• Thinner than epith. of
gingiva.
• Lacks epithelial ridges
i.e. has smooth interface
with lamina propria.
• Continuous with gingival
epith. & attachement
epith.
• All three epithelia have a
continuous basal lamina
Gingival SulcusGingival Sulcus

99. Lining MucosaLining Mucosa
The epith. is The epith. is thickerthicker than that of than that of
masticatory mucosa.masticatory mucosa.

The epith. is The epith. is nonkeratinizednonkeratinized..
The surface is The surface is flexibleflexible (withstand (withstand
streaching).streaching).
The interface with C.T. is The interface with C.T. is smoothsmooth..

100. The lamina propria is The lamina propria is thickerthicker than in than in
masticatory mucosa.masticatory mucosa.

It contains fewer irregular collagen fibers.It contains fewer irregular collagen fibers.

It contains It contains elastic fibers elastic fibers (control the (control the
extensibility).extensibility).

101. Where lining mucosa covers Where lining mucosa covers musclemuscle (lip, (lip,
cheeks, underside of the tongue), the cheeks, underside of the tongue), the
mucosa is fixed to fascia by collagen and mucosa is fixed to fascia by collagen and
elastic fibers.elastic fibers.

102. Different zones of lining mucosa vary from Different zones of lining mucosa vary from
one another in the structure of their one another in the structure of their
submucosa.submucosa.

103. The alveolar and vestibular mucosa and The alveolar and vestibular mucosa and
mucosa covering the floor of the mouth are mucosa covering the floor of the mouth are
attached looselyattached loosely to the underlying structure to the underlying structure
by a by a thickthick submucosasubmucosa..

104. By contrast, mucosa of the lips, cheeks, By contrast, mucosa of the lips, cheeks,
and underside of the tongue is and underside of the tongue is bound bound
firmlyfirmly to the underlying muscle. to the underlying muscle.

Submucosa isSubmucosa is thin thin..

105. Different zones of the submucosa contain Different zones of the submucosa contain
minor minor salivary glandssalivary glands, and, and

Sometimes Sometimes sebaceous glandssebaceous glands (labial and (labial and
buccal mucosa).buccal mucosa).

106. Sebaceous glands in the mucosa of the cheek
Appear as yellowish spots(Fordyce’s granules(
Sebaceous
glands
Salivary glands

107. Alveolar mucosa
Floor of the mouth
Vestibular fornix
Loosely Attached “Movable”mucosa
loosely attached
to periosteum
loosly attached to
underlying structures
allows mobility of the tongue
allows mobility
of lips and cheeks

108. Alveolar
mucosa
mucogingival
junction
Epithelium:st. sq. nonker. epith.,
few or no epith. ridges
lamina
propria:
Loose C.T,
collagen & elastic fibers
Submucosa: thick elastic fibers
& mixed salivary
glands
Floor of the mouth Very thin epith.
lamina propria
highly vascularized
Vestibular fornix
Loosely Attached“Movable”mucosa

109. Firmly Attached Immovable mucosaFirmly Attached Immovable mucosa
Lip & cheek
mucosa
Inferior surface
of the tongue
Soft palate
Oral side
Nasal side:
pseudustratified
ciliated epith.

110. Specializd MucosaSpecializd Mucosa
Location: dorsal surface of the tongue.Location: dorsal surface of the tongue.

Covered by masticatory mucosa Covered by masticatory mucosa
(keratinized).(keratinized).
Containing different types of ling. papillae. Containing different types of ling. papillae.
Some of these papillae bear taste buds.Some of these papillae bear taste buds.

111. )kerat. and nonkerat.(
)nonkerat.(

112. 112) C•M•UOOUALOUML
) C•M•UOOUALOUML


Microanatomy of the tongueMicroanatomy of the tongue::
Specialized mucosaSpecialized mucosa : :
) ) Dorsal surface of the tongueDorsal surface of the tongue(.(.
The dorsal surface of the tongue is The dorsal surface of the tongue is
divided intodivided into::
Anterior 2/3 or papillary or movable Anterior 2/3 or papillary or movable
partpart..
Posterior 1/3 or root or base of the Posterior 1/3 or root or base of the
tongue (lymphatictongue (lymphatic(.(.
These two parts are separated by These two parts are separated by V V shapeshape
sulcus terminalssulcus terminals..

113. 113
Anterior 2/3 or oral part or Anterior 2/3 or oral part or
papillary partpapillary part::
Covered by tongue papillae Covered by tongue papillae
taste budstaste buds..) C•M•UOOUALOUML
) C•M•UOOUALOUML


Microanatomy of the tongueMicroanatomy of the tongue::

114. 114RMLO• •
RMLO• •
O
O
Tongue papillaTongue papilla: :
))11(( Filliform papillaFilliform papilla::
ConeCone shaped shaped..
High conical structure High conical structure
arranged in parallel rows arranged in parallel rows
and near the post 1/3 the and near the post 1/3 the
raw became parallel toraw became parallel to V V
shape sulcus terminalsshape sulcus terminals..

115. 115
•It is covered by Stratified Squamous Keratinized It is covered by Stratified Squamous Keratinized
EpitheliumEpithelium

•It has a C.T core (primary papilla) that may send from It has a C.T core (primary papilla) that may send from
1-2 secondary papilla1-2 secondary papilla..
•It does It does notnot contain contain taste budstaste buds..

116. 116M
M
S
S
LO
LO
3M CO• •L5OMO L
3M CO• •L5OMO L
L
L
))22( ( Fungiform papillae: (fungus likeFungiform papillae: (fungus like((

MushroomMushroom like narrow at the like narrow at the
base with smooth rounded topbase with smooth rounded top..
Present on the dorsal surface of Present on the dorsal surface of
the Tongue between the the Tongue between the
Filliform papillaFilliform papilla..
Are numerous at the tip of the Are numerous at the tip of the
tonguetongue..
Covered by ST.SQ. Non K. EPCovered by ST.SQ. Non K. EP..

117. 117
Fungiform papillaeFungiform papillae
Primary C.T papillae 1-3 Primary C.T papillae 1-3
secondary C.T papillae make secondary C.T papillae make
the B.V. near its surface so it the B.V. near its surface so it
appears redappears red..
It contains 1-2 taste budsIt contains 1-2 taste buds..
The papilla at the tongue The papilla at the tongue tiptip is is
responsible for the responsible for the sweetsweet
sensation and that of the sensation and that of the
laterallateral borders is responsible borders is responsible
for for saltsalt sensation sensation. .

118. 118M
M
•
•
LO
LO
C••ULO• •
C••ULO• •


))33( ( circumvalate papillacircumvalate papilla::
From 4-12 in numberFrom 4-12 in number..
present anterior to sulcus present anterior to sulcus
TerminalisTerminalis..
They not protrude above the They not protrude above the
tongue surfacetongue surface..
It is surrounded by deep It is surrounded by deep
troughtrough..
the wall of the trough the wall of the trough
contains taste budscontains taste buds..
Von EbnerVon Ebner minor salivary minor salivary
glands open in the bottomglands open in the bottom. .

119. 1197MO*MLCO•MS
7MO*MLCO•MS
Von Ebner glandsVon Ebner glands

120. 120
Circumvalate papillaCircumvalate papilla
The trough cleans food debris The trough cleans food debris
and help taste sensationand help taste sensation..
It has narrow base and wide It has narrow base and wide
surface with central core of surface with central core of
C.T which send secondary C.T which send secondary
C.T papilla to the ST.SQ. Non C.T papilla to the ST.SQ. Non
K. EPK. EP..
It is responsible for It is responsible for bitterbitter
sensationsensation..

121. M
M


LO
LO
3 •ULO• •5OL•O L
3 •ULO• •5OL•O L
LU
LU ))44( ( Foliate papilla: (leaf likeFoliate papilla: (leaf like(.(.
Present as sharp parallel Present as sharp parallel
clefts on the lateral side of clefts on the lateral side of
sulcus Terminalissulcus Terminalis..
It surrounded by through in It surrounded by through in
which Von Ebner minor which Von Ebner minor
Salivary glands openSalivary glands open..
It contains taste budsIt contains taste buds..
It responsible for It responsible for SourSour
sensationsensation..

122. 122R•ULOS
R•ULOS


Taste budsTaste buds::
SiteSite::
All tongue papilla except All tongue papilla except
Filliform papillaFilliform papilla..
Soft palateSoft palate..
Posterior surface of epiglottisPosterior surface of epiglottis. .
ShapeShape::
 ovoid with roundedovoid with rounded
 Base toward C.T and pointedBase toward C.T and pointed
 At the outer surface (taste At the outer surface (taste
porepore(.(.
SizeSize::
8080 M height x 40 M widthM height x 40 M width..

123. 123
HistologyHistology:-:-
Outer supporting cellsOuter supporting cells typetype: :
cells like layers of onion and cells like layers of onion and
are in contact with the are in contact with the
epithelium they are rod shape epithelium they are rod shape
with basal nucleuswith basal nucleus..
Inner supporting cellsInner supporting cells type:type:
rod shape cells with basal rod shape cells with basal
nucleusnucleus. .
Neuro- epithelial cells Neuro- epithelial cells
(receptors of taste stimuli) (receptors of taste stimuli)
they are 10-12 and present they are 10-12 and present
between the inner supporting between the inner supporting
cellscells..

124. Taste Bud
3- Neuroepithelial cell
1- Outer supporting cell
2- Inner supporting cell
Taste pore

125. 125
Taste budsTaste buds

126. 126
They are They are slender
with basally with basally dark dark
stainedstained nucleusnucleus , ,
and apically and apically stiff stiff
bristlebristle like process like process
extended to the extended to the
space beneath the space beneath the
taste poretaste pore..

127. 127
Nerve plexus present Nerve plexus present
beneath taste bud in the beneath taste bud in the
C.T same nerve fibers C.T same nerve fibers
enter it and end in contact enter it and end in contact
with the taste cellswith the taste cells. .

128. Taste SensationTaste Sensation
1. Any substance to be tasted must become 1. Any substance to be tasted must become
dissolved in saliva and passed to the taste dissolved in saliva and passed to the taste
pores. pores.
2. This affects the microvilli of the taste cells 2. This affects the microvilli of the taste cells
(hairlets).(hairlets).
3. So, a nerve impulse is set up and 3. So, a nerve impulse is set up and
transmitted along the sensory nerve fibers transmitted along the sensory nerve fibers
to the brain.to the brain.

129. SweetSweet is tasted at the tip (fungiform). is tasted at the tip (fungiform).
SaltySalty at the lateral border of papillary at the lateral border of papillary
portion (fungiform).portion (fungiform).

BitterBitter (circumvallate-midde area). (circumvallate-midde area).

SourSour (foliate-lateral area) on the posterior (foliate-lateral area) on the posterior
part of the tongue.part of the tongue.

(bitter is also tasted on the palate).(bitter is also tasted on the palate).

130. Taste distribution
Sweet & salt: Fungiform
Sour: Foliat
Bitter: Vallate (palate(

131. Sweet and salty taste sensations are Sweet and salty taste sensations are
mediated by chordatympani.mediated by chordatympani.
Bitter and sour taste sensations are Bitter and sour taste sensations are
mediated by glossopharyngeal nerve.mediated by glossopharyngeal nerve.

132. 132*#SU •U•
*#SU •U•
LR
LR
Lingual tonsilsLingual tonsils: :
It is small rounded or oval elevations It is small rounded or oval elevations
composed of lymphatic nodules in the composed of lymphatic nodules in the
under lying C.T known as lingual under lying C.T known as lingual
follicle is covered by ST.SQ. Non K. follicle is covered by ST.SQ. Non K.
EP. That extends darn in many sites to EP. That extends darn in many sites to
form lingual cryptform lingual crypt..
The lymphatic tissue composed of The lymphatic tissue composed of
germinal centers and diffused lymphatic germinal centers and diffused lymphatic
tissue fill the spaces between these tissue fill the spaces between these
centerscenters..
Into the bottom of these lingual crypt Into the bottom of these lingual crypt
duct from the duct from the WeberWeber minor salivary minor salivary
glands openedglands opened..

133. Lingual cryptLymphatic nodules
)follicles(
Weber salivary glands

134. 134,RAA •SAR R #SR
,RAA •SAR R #SR
Inferior surface of the tongueInferior surface of the tongue
•Firmly attached lining mucosaFirmly attached lining mucosa. .
•Non keratinized epitheliumNon keratinized epithelium..

135. 135/S•UR• R #SR
/S•UR• R #SR
R
R
Muscles of the TongueMuscles of the Tongue
Two groups of tongue:Two groups of tongue:
muscles the muscles the intrinsicintrinsic and and
extrinsicextrinsic are united into one are united into one
organ ,however, has separate organ ,however, has separate
structural and functional structural and functional
characteristicscharacteristics
11--ExtrinsicExtrinsic
Genioglossus MuscleGenioglossus Muscle
Hyoglossus MuscleHyoglossus Muscle
Styloglossus MuscleStyloglossus Muscle

136. 136/S•UR R #SR
/S•UR R #SR
Muscle of the tongueMuscle of the tongue
22--IntrinsticIntrinstic
longitudinal fiberslongitudinal fibers
transverse fiberstransverse fibers
vertical fibersvertical fibers

137. 137,RAL• R #SR
,RAL• R #SR
LR
LR
Innervations of the tongueInnervations of the tongue: :
Anterior 2/3Anterior 2/3::
 Chorda Tympani for taste sensationChorda Tympani for taste sensation..
 Lingual nerve for general sensationLingual nerve for general sensation..
Posterior 1/3Posterior 1/3::
 Glosspharyngeal nerve for taste and Glosspharyngeal nerve for taste and
general sensationgeneral sensation..
 The hypoglossal nerve for motor supplyThe hypoglossal nerve for motor supply..

138. (keratinized
(No taste buds)

139. Circumvallate papilla with deep groove into which open
the duct of minor salivary glands
Keratinized epith.: superiorly
Nonkeratinized epith.: laterally
Contains taste buds laterally

142. Seen more frequently in mammals
other than human beings