5- Oral Mucosa and Salivary Glands (Mahmoud Bakr)

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



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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

Documents

5- Oral Mucosa and Salivary Glands (Mahmoud Bakr)