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7/27/2019 5- Oral Mucosa and Salivary Glands (Mahmoud Bakr)
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Griffith UniversityOral Biology 2
1009 DOH
Oral mucous membrane and
Salivary glandsDr. Mahmoud Bakr
Lecturer in General Dental Practice
B.D.S, M.D.S (Cairo University), ADC (Australia)Member of the Australian Dental Association (ADA),
the Australian Biology Institute Inc. (ABI) and the
Egyptian Dental Union (EDU)
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Learning objectives:After completing this lecture you should be able to:
1- Identify, describe and distinguish the location,
special features or functions, blood and nerve
supply, lymphatic drainage and surface
markings of major and minor salivary glandsaccording to their size and secretion; including
the histological structure and morphology of
their secretary units.
2- Describe age related changes to Enamel and their
effects.
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Learning objrctives (Cont.)
3- By observing the histological details of cells
and tissues, you should be able to use a
microscope to identify different histological
structures of Enamel and understand the
histological processes involved in preparing
slides.
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All Microscopic images are taken from the
Digital Library of the Oral Biology
Department (Cairo University).
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It is the inner moist
lining of the Oralcavity
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Oral mucous membrane
Gingiva
Alveolar mucosaVestibular
fornix
Labial mucosa
Check
mucosa
Hard
palate
Dorsalsurface of
the tongue
Ventral surface
of the tongue
Floor of
mouth
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Class i f ication o f oral mucous
membrane
1-Keratinized mucosa ( Masticatory mucosa)
(A) Gingiva (B) Hard palate
2- Non-keratinized mucosa (Lining mucosa)
(A) Firmly attached (B) Loosely attached
I- Soft
palate II-lip III-check IV-ventralS tongue
I- Floor of
mouth II-Vestibule
III-alveolar
mucosa3- Specialized mucosa
Dorsal surface of the tongue
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Firmly attached mucosa prevent biting of
the mucosa during function.
Loosely attached mucosa allow
movement of associated structures as the
tongue.
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Keratin ized and non-kerat in ized
mucosa
Stratum basal
Stratum
spinosumStratum
intermedium
Stratum
granulosum
Stratum
superficial
Odland body
Keratohyaline
Gs.
Keratenized epithelium Non-keratenized epithelium
Stratum cornium
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Keratinized Epithelium
Consists of the following layers from bottom to top:
1- Basal cell layer: (Stratum Basale)
Its a single of columnar cells attached together bydesmosomes and to the basement membrane byhemi-desmosome.
Its the least differentiated layer responsible forrenewal of the most superficial layers that shed off
during function.
It has the criteria of protein forming cells.
(what are they?)
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2- Prickle (Spinous) cell layer:
(Stratum Spinosum)It consists of 4-6 layers of polyhedral cells attached to
each other by desmosomes and to the superficial anddeep layers by hemi-desmosomes.
There are intercellular spaces (bridges) between thecells giving it the Prickly(Spinous) appearance.
The most deep layers of Stratum Spinosum shares thesame functions with the Basal cell layer, while thesuperficial layers share the same functions withStratum Granulosum.
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So
Stratum Basale + deep layers of StratumSpinosum =Stratum Germinativum
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3- Granular cell layer: (Stratum Granulosum)
It consists of 2-3 layers of flat cells attached togetherby desmosomes and to the superficial and deeplayers by hemi-desmosomes.
It contains Keratohyaline granules that will formKeratin later on.
It contains Odland bodies which are responsible forthe thickening of the plasma membrane thickeningthat occurs prior to Keratinization.
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Odland bodies
In keratinized epithelium its Tubular with
parallel lamellae.
In Non-Keratinized epithelium its rounded
with amorphous core.
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4- Cornified cell layer: (Stratum Cornium)
(Keratin layer)It consists of an amorphous acidophilic layer of
dead cells and tonofilaments.
Its function is only a protective function.
It is formed as a result of fusion of keratohyaline
granules which discharge their contents afterthickening of the plasma membrane by Odland
bodies.
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Types of Keratin
1- Orthokertin:It contains no remnants of nuclei or cell
organelles
2- Parakeratin:It contains some remnants of nuclei or cell
organelles
3- Incomplete Keratinization:
The cells become rehydrated again by fluidsfrom intercellular spaces. This happens asa result of malfunction of Odland bodies
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Non-Keratinized Epithelium
1- Basal cell layer: (Stratum Basale)
Exactly the same as in Keratinized Epithelium.
2- Intermediate cell layer: (Stratum Intermediate)It consists of 8-11 layers of polyherdal cells that have thefollowing differences compared to the Prickle cell layerof Keratinized epithelium:
A- Larger
B- Closer to each other (no intercellular spaces)
C- Thicker (more layers)
All these differences are to compensate for the lack ofthe protective Keratin layer.
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3- Superficial cell layer: (Stratum Superficial)
It consists of 3-4 layers of flat cells.
It contains no Keratohyaline granules.
Odland bodies are rounded with amorphous core.
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Basement membrane
The Basement membrane separates between
epithelial and C.T.
Rupture of the Basement membrane and direct
communication between Epithelium and C.T
is a sign of Malignancy.
Histologically, it is an acidophilic structureless
band.
By using E.M the basement membrane is
known as Basal lamina.
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Basal lamina consists of:
A- Lamina Densa: Electrodense band
45nm thick.
B- Lamina Lucida: Electrolucent band of
50nm thick.
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1- Thickening of the adjacentcell membrane.
2- A pair of attachment plaque.
3- Tonofilaments.
4- Extracellular structure.
The desmosomes
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The hemi-desmosomes and basal lamina
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Keraten ized and non-keraten ized
mucosa
Keratenized mucosaNon-keratenized mucosa
OrthokeratinParakeratin
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Keratinocytes
and non-keratinocytes
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3- Merkels cell2- Langerhans cell1- Pigment cell
(Melanocyte, blast)
They do
not have
long processes.
Contain small
membrane boundedgranules
Similar in shape.
Contain granules
(langerhans granules)
Small body with long
slender and branched
process present in
the I.C.S of epith.
contain melanin
granules
(melanosomes)
Shape
Basally in
epithelium
High level cell and may
be found at lower
levels.
Basal and parabasal
layers
Location
Not stained socalled
( Clear but not
dentritic cell )
Not stained so called( Clear dentritic cell )
Not stained so called( Clear dentritic cell )
Stain byH&E
Gold chlorideDOPA reaction ( for
tyrosinase enzyme)
Special
stain
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Neural crest cellsBone marrowNeural crest cellsOrigin
-Little tonofilaments.
-Little desmosomes.
-Nerve cell seen to beassociated with the cell
with synapse-like cleft.
No tonofilaments.
No desmosomes.
No tonofilaments.
No desmosomes.
Cell
junction
Responding to touch.1-Neural element.
2- Degenerated
melanocyte.
3- Intra epithelial
Macrophage.
4- Regulatory cells
(control epith. Cell
division and
differentiation)5- Uptake and
processing of
antigen in contact
allergic reaction
Pigmentation.
If melanosomes
engulfed by
epithelial cell
called
(Melanophore) or
by C.T. cell
(Melanophage).
Function
4- Inflammatory cells They are transient cells
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Macro-anatomy of the gingiva
Free gingiva
Free
gingival
groove
Interdental
papilla
Attached
gingivaMucogingival
junction
Alveolar
mucosa
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Pigmentation
Attached
gingiva
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Clinical consideration
Gingiva is pale pink in healthy individuals whiletheAlveolar mucosa is red.
The line that separates Gingiva from Alveolar
mucosa is called
Muco-gingival junction or Health line
(WHY?)
Because when Gingiva is inflamed it becomes red
in colour and the Health line cannot be seen.
So Health line is a sign of Healthy Gingiva
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Interdental papilla and gingival Col
Gingival col( non-
keratenized)
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Histology of gingiva
Stratified squamouskeratenized epithelium
Lamina propria
Epithelial rete peg
C.T papilla
Tall
Numerous
Slender
Irregular
No submucosa
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Gingival fibers
Dento-gingival group
Alveolo-gingival group
Circular group
Dento-periosteal group
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Macroanatomy of palate
Incisive papilla
Palatine gingiva
Antro-lateralarea (fatty
zone)
Postro-lateral
area
(glandular
zone)
Rugae area
Median
palatine
raphe
Soft palate
Uvula
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Histology of hard palate
Submucosa
Fatty zone
Glandular zone
Epithelial rete pegs
are tall and
numerous
Mucosa
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The main difference between Hard Palate
and Gingiva is that Hard Palate has a
Sub-mucosawhich consists of:
A- Fat cells in the Anterolateral zone and
act as a shock-absorber
B- Mucous S.Gs in the posterolateral zone
and facilitate swallowing as a part of themucous ring.
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But some areas of the hard palate has no
submucosa such as:
1- Palatine Gingiva
2-Median palatine raphe
3- Palatine Rugae
In these areas the mucosa is attached
directly to the periosteum of palatine bone.
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Soft palateOral sideNasal side
Respiratory epithelium
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Lip
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LipVermilion border
Mucous side
Skin side
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Skin
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Skin
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Skin side of the Lip
It differs from any keratinized Epithelium in two ways:1- It contains Skin appendages
A- Hair B- Sweat glands C- Sebaceous glands
2- Contains an additional clear layer between StratumGranulosum and Stratum Cornium called Stratum
Lucidum which contains an oily material called
Eliadin that helps keeping moisture in skin.
This oily material dissolves during preparation of the
slide leaving this layer as a clear layer.
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Skin appendages
Hair follicle
Sebaceous gland
Sweat
glands
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Cheek mucosa
Nonkeratenized
epith
elium
Mixed
salivary
gland
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Specialized mucosa
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Tongue papillae
1- Filliform pap. 2- Fungiform pap.
4- Folliate pap.
3- Circumvallate pap.
Taste bud
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Circumvallate papilla
Trough
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Taste bud
3- Neuroepithelial cell
1- Outer supporting cell
2- Inner supporting cell
Taste pore
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Taste sensation
Sweet
Salt
Sour
Bitter
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Lingual tonsil
Weber salivary gland (Pure
mucous gland
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Dento-gingival junction
Hi t i f D t i i l j ti
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Histogenesis of Dento-gingival junction
12
34
Desmolyticenzymes Epithelialplug
1ry D.G.J (from
Reduced E. E.)
2nd D.G.J.
(from oral E.)
D t i i l j ti
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Dento-gingival junction
Histology of Dento-gingival
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Histology of Dento gingival
junction
Basal cell
layer
External
basal
lamina
Lamina
propria
Superficial
flat cells
Hemidesmosomes
Internal
basal
lamina
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Stages of passive eruption
Anatomical crown
Clinical crown
Coronal end (E)
Apical end C.E.J.
1 year before shedding in deciduous
teeth and in perm. Till 20-30 years.
First stage
Anatomical crown>Clinical crown
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Second stage
Anatomical
crown
Clinical crown
Coronal end (E)
Apical end (C).
Persist till 40 years
Anatomical crown>Clinical crown
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Third stage
Anatomical
crownClinical crown
Coronal end (C.E.J.)
Apical end (C)
Transitory stage
Anatomical crown=Clinical crown
Fourth stage
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Fourth stage
Anatomical
crownClinical crown
Coronal end (C)
Apical end (C)
Persists till the tooth lost
Anatomical crown
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Effect of Smoking on oral tissues
We all know that smoking is harmful to our
health.
Besides the obvious effects of smoking on
oral tissues such as Staining of teeth andHalitosis (Unpleasant breath smell), there
lots of other changes happening at a
cellular level that our patients need toknow about.
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Severity of periodontal disease related to number of cigarettessmoked per day.
As in Caranza , patients who smokes 100 cigarettes or more areconsidered Smokers.
50% of aggressive periodontitis patients are smokers. May causetissue ischemia, as Nicotine is a powerful vasoconstrictor andimmunosuppressor, so the problem is due to :
1- Change vascularity (Vasoconstriction) reducing the amount
of O2 in subgingival area harbor more Anaerobic pathogenicsubgingival Microflora (A.a. and P. gingiv al is)
2- The defense mechanism of PMN, by decreasing the Numberand Functions (Chemotaxis and Phagocytosis).
3- Depress the T- Helper Lymphocytes Decrease the stimulationof B-cells function Decrease the Antibodies formationagainst bacteria.
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4- Nicotine bind to bacteria and release of Tissuedestructive enzymes ( IL-1 and IL-4 ) by Host Over-reaction Immune system More tissue destruction.
5- Nicotine Impair Revascularization of Gingival andHard tissue, inhibits Collagen fibers production, fibroblast Collagenase destructive activity, andsuppresses the proliferation of Osteoblast and thislead to Healing retardation.
All this occur due to less vascularity to the area due tovasoconstriction, and as result of this Bacterialactivity increases and more bone destruction occursand PD progress. Also there will be wound healingand susceptibility to infection.
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Saliva
Definition:-A Saliva is a complex fluid produced bythe salivary glands, whose importantrole is maintaining the well being of the
mouth.For example patients with deficiency ofsalivary secretion experience difficulty
in eating, speaking& swallowing &become prone to mucosal infections &rampant caries.
Composi t ion of sal ivaB
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Composi t ion of sal iva-B
%97Water:-1
sodium, potassium, chloride,Electrolytes:-2
Calcium, magnesium, phosphate& fluoride.
rich-prolineamylase,Secretory p roteins:-3
protein, mucins, histatin, cystatin,peroxidase, lysosome.
.IgM,IgG,IgAImmunoglob l ins :-4
: glucose, aminoSmal l organic molecules-5
acids, urea, uric acid& lipids.cyclic adenosineOther components:-6
monophosphate-binding proteins,& serumalbumin
Funct ions of sal iva-C
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Funct ions of sal iva-CProtect ion:-1
*The lubricant saliva form a barrier againstnoxious stimuli& microbial toxins.
*Its mechanical washing action flushes away
non adherent bacterial toxins& deris from themouth.
*Clearance of sugar by salivas washing action
limits action of acidogenic plaque bacteria
*The Ca- binding proteins in saliva help to formthe salivary pellicle which behaves as a
protective membrane
Buffer ing:-2
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*It denies many bacteria from optimal
environmental conditions to colonize.
*Acids produced by plaque microorganisms if
not rapidly buffered& cleared by saliva can
demineralize enamel.
*Much of the buffering capacity of salivaresides in its bicarbonate &phosphate ions.
Digest ion:-3
*It provides taste acuity.
* Neutralize esophageal content.
*Dilutesgastric chyme.
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* Form the food bolus.
*Due to its amylase contents, it breaks down
starch.
Taste:-4
* It enables the pleasurable sensations of foodto be experienced.
*It permits the recognition of noxious
substances.
*Contains protein Gustin necessary for growth
&maturation of taste buds
A t i i b i l t i5
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An t im icrobial act ion :-5
*Lysosomes can hydrolyze the cell wall of
some bacteria. Lactoferrin binds free ionand in so doing deprives bacteria of this
essential element.
*The major salivary immunogloblin, IgAhas the capacity to clump or agglutinate
microorganisms.
Maintenance of too th integr i ty :-6
*Post eruptive maturation through
diffusion of ions as Ca , phosphorus , mg
&chloride from saliva into enamel.
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DEFINITION:
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*Salivary glands areMerocr ineExocr ineglands that produce and secrete saliva.Sal iva is involved in the digest ive pro cess and
in the pro tect ion o f oral tissue
exocytos ismanner invo lvesmerocr ine(Merocr ine
or the discharge of on ly Secretory mater ial w ithou t
any loss o f cytoplasm ) related to the surface( means a glandExocr ine
epithelium by a duct)
DEFINITION:
Histo log ical st r ct re
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Histo log ical structu re
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Basic structure of salivary glandsA-Parenchymal element:
1-Secretory cells( serous & mucous acini)2- Non secretory cells:
a-Myoepithelial cells b-Oncocytes
3- Duct system
B- Connective tissue element
1-Cells 2-Fibers
3-Groud substances 4-Blood supply
5-Nerves
Parenchyma:
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1-Acini
2-Ducts
3-Myoepithelal
cells (Basket cel ls)
1
2
3
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Parenchymal element:-A
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y
Secretory cells (Acini)-1
A-SerousB- Mucous
C- Mixed
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Serous acini-A
*Spherical or rounded
acni
*Small*Narrow lumen
*cells are pyramidal
*Spherical nucleus in
Basal 3rd
Histological structure
Ultra structu re: 3
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1-Nucleus basal ly
2-Deeply stained basophillic
cytoplasm3-Apical cytoplasm contains
Zymogen secretory granules
4-Cytoplasmic organelles:
a-Mitochondria, b-(4-6)golgi saccules
c-Lysosomes, d- free ribosomes, e-RER
5-cytoplasm show basal striation due to
numerous mitochondria arrangedparallel
6-Intercellular canaliculi ends in form ofjunctional complex
1
a
b e
5
6
Ultra structure:
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Mitochondria RER
Free ribosomes Golgi apparatus
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Mucous acini-B
Histological structure
*Tubular long acini
*Large
*Larger lumen*Short cuboidal or
flattened cell
*Flattened or angularnucleus
Ultra stru ctu re:Aa
b
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1- Nucleus basal ly compressed
2- Cytop lasm :
A -Vacu lated l igh t ly stained
B- the cel ls appear empty
Except :
A thin r im o f Cytoplasm formtrabecular netwo rk
3- Cytoplasm ic organel les:
a-mitochondria, b-(10-12)
prom inent go lg i saccu les
C- few RER, d- few m icrov i l li
4- Very few in tercel lu lar
Canal icul i
1
Aa
RDR
Vaculated
cytoplasm
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Non secretory cells:-2Myoepithelial (basket-a
4 5
6
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Myoepithelial (basket-a
cells)
1- Spindle shaped2-Related to secretory
&intercalated duct.
3- Has 4-8 processes.
4- Attached to the
underlying cell by desmosomes.
5- Contain many microfilament which aggregate
forming dark bodies
6- Cell organelles are perinuclear
7- Has a contractile function.
12
3
45
6
78
6
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b- Oncocytes:
Are small rounded cells with deeply stained
shrunken nuclei
Contain very few cell organelles
It represents an age change and may be related
to neoplasm formation (oncogenesis)
Duct system-3
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y
Intralobular (within lobules)
a- Intercalated. b-Striated.
Interlobular ( in C.T. between lobules):
a-Excretory ducts b- Main ducts
1-In tralobular (w ithin lobules)
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Intercalated-a
1- Small diameter.
2-Lined by simple cuboidalepithelium
3-Central nucleus.
4- Little cytoplasm.
5- Basal RER.6- Apical golgi complex
7- Few secretory granules
8- Numerous in watery
secreted gland ( parotid)
3
5
6
7
1-Intralobular (within lobules)b Striated:
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b-Striated:
1- Lined by a single layer of
columnar cells.
2- Central nucleus.
3-Esinophillic cytoplasm.
4- Prominent Basal striations due
to :a- membrane infolding
b-numerous elongated
mitochondria
5- a-Cell organells, b-junctional
complex & desmosomes are
present
2
ab
4
5 a
5 b
3 Exc retory duc t and main duct
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3-Exc retory duc t and main duct
1- Interlobular ducts lined
by tal l colum nar cells .
2- Interlobar ducts are lined
by pseudostrat i f iedcolum nar epi thel ium wi th
goblet cel ls .
3- Main duct is lined byst rat i fied squamous
epithel ium
1 2
3
Goblet cell
FUNCTIONS OF SALVARY GLAND DUCTS
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DUCT
MAIN EXCRE.DUCT EXCRETORY DUCT STRIATEDDUCT INTERCALATED
Modification of
primaryPassive conduit
Sec. Granules.
Minor contributionin secretion
Isotonic or Slightly hypertonicthan
plasma.
Na+, cl- Conc. = Plasma.
K+ ConcNa+ andPlasma .
1Contain Kallikrein enzyme
synthesis of glycoproteins.
2
Presence of vesicles and lysosomespinocytotic activity.3Basal infolding + conc. Mitochondria +
Basal portion of cells contain Na+ & K+
activated adinosine triphosphatase
(transport enzyme)
water and electrolyte transport .
Reabsorbed
from primary
secretion .
Secreted
in primary
secretion.
Secreted.Reabsorbed
Note: At increased flow rates Na+ and CL- conc.
increase, while K+ decreases., as the secretion is
in contact with the ductal epithelium for a short
time.
Acinus
C ti ti l tB
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Connective tissue elements-B
:Cells1a-Fixed C.T. cells b-Migrating cells
Fibroblasts, Plasma cells, Macrophages
Mast, and Fat cells. Leukocytes.Fibers:-2
Reticular & collagen.
Ground substances:-3a-Glycoproteins b-proteoglcans
Classification of salivary glands:
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Classification of salivary glands:
I- According to site
II- According to size
III- According to secretion
I. According to site:O l tib l
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Oral vestibule:
Labial glands (upper and lower)Buccal glands.
Parotid glands.
Oral cavity proper:
- Palatine glands (of hard and soft palates and uvula).
- Glossopalatine glands.
- Lingual glands (Weber glands, von Ebner glands,
Blandin Nuhn glands)
- Sublingual glands (major and minor).
- Submandibular glands.
II- According to size
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gMajor salivary glands:
-Parotid glands.
- Submandibular gland.
- Sublingual gland (major)
Minor salivary glands:
-Labial and buccal glands.- Palatine glands.
- Glossopalatine gland.
- von Ebner gland.
- Weber gland.
- Blandin Nuhn glands.
- Minor sublingual glands.
III According to secretion
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III- According to secretionA) Pure serous glands:
- Parotid gland of adult
- von Ebner gland.
B) Pure mucous glands:
-Palatine glands.
- Glossopalatine glands.
- Weber glands.
-Minor sublingual glands.
-Labial gland.
C) Mixed glands:
- Labial and buccal glands.
- Submandibular gland- Major Sublingual gland.
- Blandin Nuhn glands.
- Parotid (new born)
Pure serous acini
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Pure serous acini
Mixed acini
Types of human salivary glands
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Types of human salivary glands
Major salivary glands :-1
A- Parotid. b- submandibular. c-sublingual.
Mino r sal ivary g land s:-2
A-Labial &buccal gland. B- Palatine gland.
C- Glossopalatine gland. D-Lingual gland.
Major sal ivary g lands:-1
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A- Parotid glandThe largest
Its superficial portion lies subcutaneously
Its deeper portion lies behind the ramus
Pure serous in adult& mixed in infant &old age
Main duct Stensens duct
C.T.capsule surround it &send septa to divide
the gland into lobes &lobules
Secretes 25-30%of salivaIntercalated duct longer than in the other glands
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b Submandibular gland
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b- Submandibular glandNext in size
Lies in the submandibular triangle behind &below the free border of the mylohyoid M. with
small extension above it.
Mixed predominatly serousMain duct Whartons duct
Extensive C.T. capsule
Secretes 60-70%of secretion
Straited ducts longer than those of the parotid.
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C-Sublingual gland
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Smallest.
Lies between floor of the mouth &mylohyoid
muscle.
The major gland is mixed predominantly mucous.
The minor gland are pure mucous.
Major-Bartholins duct opens near sumand.duct.
Minor-Rivinus duct 8-10 open in sublingual fold.
Poorly defined C.T. capsule with prominent C.T.
septa.Secretes 5%or less of saliva.
Sublingual gland
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Sublingual gland
Minor salivary g lands:2
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Minor salivary g lands:-2
- Distributed throughout the submucosa.
- Small, discrete masses.
- Posses numerous short ducts that open
directly in the oral cavity.
- Lack distinct capsule.
- Secrete 7% of saliva.
- Focal accumulation of lymphocytes around
their duct wall.- Secrete high amount of IgA concentration.
A-Labial &buccal gland
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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.
B- Palatine gland&
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C- Glossopalatine gland.
Palatine:
Pure mucous.
In H.P.250 Soft P.100
Uvula12
Glossopalatine:
Pure mucous.Found in the isthmus region.
Gland of hard palate
N hBl di1
D-Lingual gland
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Nuhn-Blandin-1
An t . part mucous
Post . Part- m ixed mucous.
Open in the ventral surface
(VE)EbnerVon-2
Pure serous
under c ircum val late& fol l iate papi l lae
Washing funct ion
Contain amylase& l ipase enzymes
Weber-3
Pure mucous
Open in the l ingual cryp t
MAJOR FEATURES OF SALIVARY GLANDS
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NerveSebaceous
Glands
Lymphoid
TissueFatGlandsDuctFeatureGland
Facial
NerveYesYesYesSerous
Stensen's
duct
Largest
major
salivary
gland
Parotid
NoneNoneNoneYesMucou-SerousWharton'sduct
Second
largest
majorsalivary
gland
Sub-mandibulargland
NoneNoneNoneYesMucou-
Serous
Bartholin's
duct,
Rivinus
ducts
Smallest
ofmajor
salivary
glands
Sub-
lingual
gland
NoNoneNoneYes(Tongue)
Mucous
except
forthose
in
tongue
Small
Scatteredthroughout
the tongue,
palateand
lip
Smallsalivary
glands
Funct ions o f Sal ivary g lands
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1- The most important function is salivaproduction& secretion.
2- Play a major role in iodine metabolism,sincethe cells of the striated ducts are engaged iniodine concentration.
3- The parotid gland secrete a hormone calledparotin which:
a.Promotes growth of mesnchymal tissues.b.Lowers serum calcium level.
c.Stimulates calcifications&leucocytesproduction in bone marrow.
4- They secrete lots of enzymes &protein active
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substances of multiple effects e.g. peroxidase,
lysosome, thiocyanate, sialin&amylase.
5-Salivary gland of certain animals species are
active in producing epidermal &nerve growth factorinvolved in wound healing.
6-The plasma cells found in the stroma of thesalivary glands form salivary immunogloblins
particularly IgA which plays a role in the mucosal
immune mechanism of the oral cavity
Age changes o f sal ivary glands
1 F tt d ti h
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1- Fatty degenerative change.
2- Atrophy of a part or awhole terminal portion
with its replacement by fibrous tissue(Fibrosis).
3-Accumulation of lymphocytes in the stroma.
4- in the salivary secretion which leads toxerstomia.
5- xerstomialeads to difficulty ineating&swallowing as well as in dental
caries.6- Oncocyte cells in number& may formneoplasm in old people
degenerative change.Fatty
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Young age
Old age
Clinical consideration
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Clinical consideration
Xerostomia: (Dry mouth)It decreased secretion of Saliva.
It may be caused by several factors:
A- Age b- Psychological factors
C- Drugs (cold medications and Anti-depressant)
D- Auto-immune diseases (Sjogrens syndrome)E- Salivary gland stone (Sialolithiasis)
The consequences of Xerostomia are:
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The consequences ofXerostomia are:
1- Increased caries and periodontal disease
rates and severity
2- Difficulty in swallowing
3- Improper retention of Dentures
4- Cracking of Oral mucosa
5- Halitosis (Bad Breath)
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Thank you&
Good luck