oral mucosa Flashcards
a mucous membrane is an organ composed of what two tissues?
epithelium
connective tissue: lamina propria and sometimes submucosa
____ tissue is also embedded in oral mucosa, lingual, and palatine tonsils
lymphoid
the oral mucosa, especially the _____, but also the ____, contain cells of the immune system that are able to mount a protective response against infection
lamina propria; epithelium
____ synthesize and secrete several immune molecules and also anti-microbial peptides, called ____
epithelial cells; beta-defensins
beta defensins are ____ rich and ____
cysteine; cationic
beta defensins bind to negative charges on ____ and _____
bacterial membranes; permeabilize
oral mucosa is highly innervated, which augments ____ and _____ functions
protective; ingestive
all oral epithelium is classified as _____ epithelium; it is a ____ population of cells
stratified squamous; self-renewing
____ (aka epithelial cells) are the most numerous in the oral epithelium
keratinocytes
non keratinocytes in the oral epithelium
merkel cells - sensory- basal layers
melanocytes- pigment cells- basal layers
langerhans (dendritic) cells- immune- supra-basal layers
____ and ____ have a distinct clear appearance in sections stained with classic H&E techniques; can be distinguished from each other by location
langerhans cells; melanocytes
melanocytes make melanin using the enzyme _____
tyrosinase
alveolar mucosa is ____ while gingiva is ____
non-keratinized; keratinized
more superficial layers of keratinized and non-keratinized epithelium are distinct; keratinized epithelium has ____ layer and non-keratinized epithelium has ____ layer
granular; intermediate
all epithelial cells are keratinocytes that contain ____
cytokeratins
cytokeratins are a large (about 30) ____ family of proteins that assemble into _____ to provide cytoskeletal support
multigene; intermediate filaments
2 major groups of cytokeratins
type I (acidic) and type II (basic)
cytokeratins are the intracellular component of ____ and ____
desmosomes; hemidesmosomes
cytokeratins contribute to ____ in both keratinized and non-keratinized oral mucosa ; and in both types, amount of cytokeratin ____ in superficial layers
mechanical toughness; increases
keratinized specific cytokeratins promote _____ and promote binding to another molecule, ____ (main component of keratohyalin granules)
aggregration (tonofibrils); fillagrin
specific nonkeratinized cytokeratin types ____ promote aggregration
DO NOT
keratinized epithelium is ____ but less _____ than non-keratinized epithelium
tougher; flexible
membrane coating granules are membrane bound organelles, filled with _____; first appear in ____ cell layer
glycolipids; upper prickle
membrane coating granules occur in both keratinized and non-keratinized epithelia and serve as an _____ barrier to _____ substances
intercellular ; aqueous
15 nm cross-linked protein sheath comprised of loricrin and other proteins
cornified envelope (of keratinized epithelium)
lamina propria- most volume occupied by ____
ECM
cells also present in the lamina propria
fibroblasts (most numerous)
macrophages, mast cells, other inflammatory cells
components of the ECM
PGs and GAGs
glycoproteins (fibronectin)
collagen (type I and III)
ELASTIN
the relative amount of type I : type III collagen is ____ for _____ regions of the oral cavity
greater; less flexible
elastin is more prominent in ____ than in ___ or ____
oral mucosa; pulp; PDL
“stippling” of gingiva reflects underlying ____ and ____
epithelial rete pegs; connective tissue papillae
present under some regions of oral mucosa; contains larger BVs and nerves supplying superficial LP
submucosa
the submucosa contains ____ and separates the LP from ____
glands; bone and muscle
the lamina propria of lining mucosa has fewer ____ and more ____
collagen fibers; elastic fibers
the dense lamina propria of masticatory mucosa has more ____ and fewer ____
collagen fibers; elastic fibers
part of free gingiva which faces tooth, generally non-keratinized
sulcular epithelium
all components are present in the external basal lamina of the junctional epithelium, but ____ components are absent in the internal basal lamina
collagen
collagen components of the ____ provide direct connection to collagen of the _____
basal lamina; lamina propria
consistent with its origin from ____, junctional epithelium expresses a protein initially associated with _____
reduced enamel epithelium; ameloblasts (odontogenic ameloblast-associated protein or ODAM)
the ____ component of the oral mucosa and the ____ maintain a barrier that retards the movement of microorganisms to the underlying tissues
epithelial; basal lamina
types of fibers in the pulp and dentin and their functions
Adelta, C fibers, and Abeta fibers: (mostly) pain
types of fibers in the PDL and their functions:
Adelta and C fibers: (mostly) pain
Abeta fibers: proprioceptive
types of fibers in the oral mucosa and their functions:
Adelta and C fibers: pain
Adelta and C fibers: thermal
Abeta fibers: touch
(?) Adelta fibers: taste
relatively fast turnover can ____, but it can also make tissues more vulnerable to conditions that affect ____
speed healing; cell division (like chemo/radiotherapy)
“clear” cells (melanocytes and langerhans cells) are dramatically revealed by ____ of _____
lack; cytokeratin staining
tyrosinase is an ____ that is the rate-limiting enzyme for controlling the production of ____
oxidase; melanin
prickle cell layer appearance due to _____
desmosomes
keratinized epithelium can be found on:
gingiva, hard palate, dorsum of the tongue
non-keratinized epithelium can be found on:
buccal mucosa, soft palate, alveolar mucosa
cytokeratins have a central ____ core, flanked by ____ ends
helical; non-helical
cytokeratins assemble into _____ (helical regions critical)
coiled heterodimer
? heterodimers = intermediate filament (10 nM)
about 10K
strongest cytoskeletal element; resist mechanical force without breaking
intermediate filaments
rare autosomal dominant disorder caused by mutations in cytokeratins 4 and 13; affects non-keratinized epithelia; soft, white, spongy plaques that are clinically benign
white sponge nevus
cells in the superficial layers of non-keratinized epithelium retain ____ and contain ____
nuclei; cytokeratin tonofilaments
cells in the superficial layers of keratinized epithelium contain no ____ but are packed with ____
organelles; cytokeratin (tonofibril)/ fillagrin complexes
differences in chemical composition of membrane coating granules creates:
more effective barrier in keratinized epithelium
the prickle cell layer of non-keratinized epithelium contains _____, while the prickle cell layer of keratinized epithelium contains _____
tonofilaments; tonofibrils
the granular layer of keratinized epithelium contains _____
keratohyalin granules
____ is present at the epithelial/ connective tissue interface
basal lamina
epithelial/connective tissue interface is convoluted with:
epithelial rete pegs
connective tissue papillae (in the papillary layer)
reticular layer underneath papillary layer
area where lamina propria is connected to muscle, with no submucosa
tongue
lamina propria connected to bone, with no submucosa is called a _____
mucoperiosteum
areas with mucoperiosteum
gingiva
hard palate next to gingiva
rugae region
median raphe
places where there is lining mucosa:
alveolar mucosa soft palate underside of the tongue floor of the mouth inside of cheeks
places with masticatory mucosa
gingiva and hard palate
specialized mucosa found on the:
dorsum of the tongue
lining mucosa is ____ or ____ epithelium of variable thickness
non-keratinized; parakeratinized
presence of submucosa in lining mucosa?
attachment to bone or muscle is ____ and ____
submucosa usually present
attachment to bone or muscle is loose and flexible
vascular supply of maxillary gingiva
superior alveolar a.
palatine a.
vascular supply of mandibular gingiva
inferior alveolar a.
buccal a.
mental a.
sublingual a.
3 ways that vasculature can get into the gingiva
PDL
interdental septa
oral mucosa
