oral mucosa Flashcards
what lines the mouth
Moist mucous membrane like the nasal pasages and GI tract
what tissues make up the Mucous membrane
an organ of epithelium and connective tissue
what makes up the connective tissue of the mucous membrane
lamina propria and sometimes submucosa
where are blood vessels in a mucous membrane
LAmina propria/submusosa
where are minor salivary glands
Lamina propria or submucosa
ducts from noth major and minro salivary glands travel through what
connective tissue to communication with mucosal surface
where is lymphoid tissue
embeddded in oral mucosa lingual and palatine tonsils
function of oral mucosa
PRotection as a barrier, antimicrobia
INgestion
what protects more basal lamina or epithelium
epithelium more protection
antimicrobial roll of oral mucosa
Immune cells
epithelial cells
What is more important for oral mucsa anti-microbial protection lamina propria or epithelium
Lamina propria
where are immune cells found int eh oral mucosa
in the lamina propria
roll of epithelium as an anti-microbial
synth and secrete several antimcrobial molecules
what antimicrobial molecules do epithelial cell synth
beta defensins
cathelicidin
calprotectin
adrenomedulin
features of beta defensins
Cysteine rich
cationic
how does BEta defensins work
Bind to negative charges on bacterial membranes and permeabilizes it
ingestion roll of the oral mucosa
Flexibility and moist surface
Innervation of the oral mucsa
Highly innervates
roll of sensory innervation of oral mucsa
augments protective and ingestive function
how is oral mucosa sensastion different from pulp/dentin and the PDL
MOre types of sensaation
what does touch in oral mucosa
A beta
what does pain in oral muscoa
A delta and C
what does innocuous thermal
A delta and C
what does taste
A delta
is oral mucosa always the same
Varies by region, but alwyas made of epithelium and connective tissue (lamina propria and submucosa)
what type of cells are all oral epithelium
stratified squamous epithelium
Deep layesr roll of epithelium of oral mucosa
Cell division
superficial layers roll of oral mucosahed off
Migrate and mature
sruface and sloughed off
layers of oral epithelium
Superficial layer
Intermediate layer
Prickle cell layer
Basal cell layer
pros and cons of fast turnover of oral mucosa
speeds healing but more vulnerable to conditions that affect cell divisions (Chemo and radiotherapy
Turnover time
Time it takes for epithelium to entirely replace itself
what fills most of the eptihelium
Occupied by cells
what type of cell is most common in epithelium
Keratinocytes most numerous
how are kertinocytes named
On the basis of their cytokeratin
types of Non-kertinocytes in the epithelium
Merkel cells
Melanocytes
Langerhands (dendritic cells)
clear cells of the eptihlium
Merkel cells
Melanocytes
Roll of merkel cells
Sneory
Roll of melanocytes
Pigment cells
Roll of Langerhans (dendritic) cells
Immunee
location of merkel cells
Basal layers
Location of melanocytes
Basal layers
Lcation of Langerhans cells
Supra-basal layers
how are celar cells revelaed
By a lack of cytokeratin staining
structure of melanocytes
Cell bone with processes in the basal layer
how is pigment packed in melanocytes
MElanosomes
how to tell difference between Langerhan’s and Melanocytes because both have process
Langerhands in supra basal layers
is oral mucosa keratinized or non-keratiinized
different regions (alveolar is non keratinized, gingiva is keratinized)
do keratinized and nonkeratinized epitheliu lok the same
Distincitive clinical appearance
what epithelium contains keratinocytes
both kertinized and non-keratinized epithelium
what do keratinocytes express
Cytokeratins
what are Cytokeratins
large multigene family of proteins
what do cytokeratins do
Assembling into intermediate filaments to provide cytoskeletal support
Types of Cytokeratins
type I (Acidic) Type II (basic)
what is a cytokeratin made of
Central helical core flanked by non-helical ends
do all cells express cytokeratin
each cell expresses at least 2 cytokeratins ( 1 of each type)
How do cytokertatins assemble
into coiled heterodimers (helical regions cricical)
what forms an intermediate filament
10k heterodimers
Different sets of Cytokeratins are expressed by
Different epithelial layers
Different epithelial tissues
what types of keratin is expressed in the basal layer throughout the mouth
K5/14
Physical features of Cytokeratins
MEch tough to provide support
The stronest sytoskeletal element to resist mech force without breaking
Intermediate filaments
Roll of intermediate filaments between cells
Desmosomes and hemidesmosomes
mutation of Cytokeratins 5/14 Basal layer lead to
Epidermolysis bullosa simplex (EB simplex)
Commonness of EB simplex
rare
symptoms of EB simplex
blistering in response to minor trauma
most severe in epidermis but also in oral consequences
Physical characteristics of keratinized vs non keratinized epithelium
KEratinized: tougher and more impermeable
Non-keratinized: more flexible
where is keratinized epithlium found
gingiva
hard palat
where is non-keratinized epithelium found
Buccal mucosa and soft palate
what layers do both Keratinized and non-keratinized have
Basal layer
Prickle cell layers
what layers distinguish KEratinizned and non-keratinized epithelium
The more superficial layers Granular: keratinized Intermediate: non-keratinized Keratinized layer: keratinized SUperficial: non-keratinized
difference betwen keratinized and superficial layer
KEratinized: no organelles, dehydrated, tougher
superficial: organelles, flexible
Roll of Cytokeratins
Contribute to mech toughness in both keratinized and non-keratinized oral mucosa
amount of Cytokeratins as you go up in layer
Amount of cytokeratin increases in superficial layers in both types of oral mucosa
what do different cytokeratine types contribute to
differences in mech properties of keratinized vs non-keratinized eptihlia
tonofibrils
Cytokeratins that promote aggregation
Fillgrin
Cytokeratins that promote binding to another molecules as the main component of keratohyalin granules
morphology of superficial keratinized layers
Very flat
dehydrated
no organelles
packed with cytokeratin (tonofibril and fillgrain complexes)
what dont Cytokeratins do in non keratinized epithelium
Do not promote aggregation
morphology of superficial non-keratinized layers
Cells not as flat/dehrated
retain nuclei
kytokeratin tonofilaments
physical properties of keratinized vs non-keratinized epithelium
KEratinized is tougher and less flexible
what controls the permeability of keratinized and non-keratinized epithelium
Not the keratin but instead the desmosomes (more numerous in keratinized epithelia)
what are membrane coating granules
MEmbrane-bound organelles filled with glycolipids
where do membrane coating granules 1st appear
In upper prickle cell layers
where are membrane coating granules released
Released in more superficial layers to coat cell
what cells have membrane coating granules
Both keratinized and non-keratinized epithelia but have different in chem composition
greater effective barrier to keratinized epithelium
what is the roll of MEmbrane coating granules
Serve as intercellular barrier to aqueous substances
where does Membrane thickening occur
Inner face of keratinocytes in upper layers of both non-keratinized and keratinized epithleium
what kind of epithelium experiences more membrane thickening
much greater pronounces in keratinized epithlium
what is the cornified envelope
15nm of cross-linked protein sheath comprised of loricrin and other proteins to do membrane thickening
the 3rd type of simple squamish epithelium in the mouth
Parakeratinized epithelium
properties of parakeratinized epithelium
intermediate between the two types of epithlium
morphology of parakeratinized epithelium
changes similar to keratinized (tonofibril/fillagrin complex)
nucleui and organelles may be retained in superficial layers
incomplete keratinization
refers to rehydration of the dehyrated surface layer by saliva
why does hyperkeratinization occur
mech trauma or irritation causing the keratinized layer of keratinized epithelium to becoe thick
what makes up most of the volume of the Lamina propria
ECM
cells of the lamina propria
Fibroblasts (most numerous)
macrophages, mast cells, inflammatory cells
what makes up the ECM of the lamina propria
PG and GAG
Glycoproteins (fibronectin)
Collagen (type I and III)
elastin
the relative amounts of type I: type III collagen is greater for what regions of the oral cavity
greater for less flexible regions
least fleible regions of the mouth
Gingiva
most flexible regions of the mouth
Buccal mucosa
where is elastin more prominent
In oral mucosa more than pulp or PDL
what is the Epithelial connective tissue interface
Basal Lamina
shape of the Epithelial connective tissue interface
Convoluted
what is in the papillary layer
rete pegs from the epithlium
connective tissue papilla from the lamina propria
what is the papillary layer
the interdigitation of the epithelium with lamina propria
what is the reticular layer
the part of the lamina propria that is just lamina propria
what happens to gingiva to reflect the underlying rete pegs and connective tissue papillae
Stippling
where is the submucosa found
present under some regions of oral mucosa
what is found in the submucosa
larger blood vessels and nerves supplying superficial LP glands
Glands
what does the submucosa separate
Separates LP from bone and muscle
where is there no submucosa between lamina propria and muscle
the tongue
where is there no submucosa between the lamina propria and bone (mucoperiosteum)
Gingiva
Rugae region
Median raphe
where is masticatory mucosa found
Hard palate and gingiva
where is lining mucosa found
Under of tongue floor of mouth alveolar mucosa soft palate check verminon bornder of lip Dorsal tongue
what is the epithelium of lining mucosa
Non-keratinized or parakeratinized epithlium of variable thickness
thickness of lining mucosa at the buccal and labia
thick about .5mm
thickness of lining mucosa at the floor of the mouth
thin about .1mm
what are the fibers of the lamina propria of lining mucosa
Fewer collagen fibers
More elastic fibers
tissue papillae of lining mucosa
relativlet short broad connective tissue papillae
submucosa of lining mucosa
usually presant
attachments of lining mucosa
Bone or muscle atachement are loose and flexible
Clinical implication of lining mucosa
Incisions more likely to gape and need to be sutured
Injections less painful
Epithelium of the exterior skin of lip
Keratinized
Thickness of lip exterior skin
Thinnest epithelium
what is found in the exterior skin of the lip
Sweat glands
Sebacous glands
hair follicles
Epithlium of the vermillion zone
keratinized
Epithelium thickness of vermillion zone
THin
blood vessl of the vermillion zone
close to the surface
glands in the vermillion zone
No sweat glands or mucous glands
epithlium of the labial mucosa
Non-keratinized
thickness of labial mucosa
Thicker epithelium
glands of labial mucosa
Mucous glands
keratin of masticatory mucosa
Keratinized or parakeratinized
Lamina propria of masticatory mucosa
Dense with more collagen fibers and less elastic fibers
papillae of masticatory mucosa
long thin connective tissue
submucosa of masticatory mucosa
Variably present in hard palate
no present in rugae region and along midline raphe, or gingiva
when submucosa not present in gingiva
Mucoperiosteum
clinical implications of masticatory mucosa
Incisions don’t gape
may not require suturing
injections hurt
part of the free gingiva which faces tooth
Sulcular epithlium
keratin of sulcular epithlium
non-keratinized generally
how special is junctional epithlium
Unique
what are parts of the periodontium
sulcular and junctional epithlium
function of junctional epithlium
forms a seal with hard tissue tooth (enamel and cementum)
orientation of junctional epithlium
long axis of tooth
cell thickness of junctional epithelium
15-30 cells thick at top
3-4 cell thick at bottom
basement membrane of junctional epithiium
straight basement membrane
keratin of junctional epithlum
keratin expression for simple epithlium
cells of junctional epithlium
relatively non-differentiated cells regardless of layer
granules of juctional epithlium
< tonofilaments
< desmosomes
no membrane-coating granules
permiablility of junctional epithlium
highly permiable
basal lamina of junctional epithlium
external (JE/lamina propria) typical molecular components
Internal or speciailized (JE/tooth)
what is found in the external basal lamina of the junctional epithlium
all components (type IV collagen, proteoglycan, VII collagen)
what components are absenent in the internal/specialized basal lamina
No collagen components
what parts of basal laina provie connection to lamina propria
Collagen of basal lamina provide firect connection to collagen of lamina propria
what proteins are made by ameloblasts during the maturation phase by intenral/specialized basal lamina of Junctional epithlium
Amtn (amelotin)
ODAM (odontogeneic ameloblast-associated)
SCPPPQ1 (secretory Ca++ binding phorphoprotein prline glutamin rich 1
what do the proteins of the junctional eptihlium do togethre
form a porous strucutre to facilitate sealing the JE to tooth surface
where does junctional epithlium extend
junctional epithlium extends all the way around the entire tooth
can junctional epithlium regenerate
yes at a rapid pace even around implants
maxillary supply to gingiva
Superior alveolar
Palatine
Mandibular supply to gingiva
Inferior alveol
buccal
mental
sublingual
how does Vascular supply get to gingiva
PDL
intergenal septa
oral mucosa
then gingva