Lecture 10: Oral Mucosa Flashcards
the mouth is lined by a _______
moist mucous membrane
what two tissues compose the mucous membrane of the mouth?
- epithelium
- connective tissue (lamina propria & submucosa)(contains blood vessels and ducts from both major and minor salivary glands)
*there is also some lymphoid tissue
which tissue of the mouth functions more as a barrier for protection?
epithelium (antimicrobials)
*lamina propria fxns more for IMMUNE CELLS
the tissues of the mouth use what for protection?
beta-defensins
*cysteine rich, bind to negative charges on bacterial membranes and permealbilize
the oral mucosa is HIGHLY INNERVATED and contrasts from the pulp, dentin, and PDL bc it is capable of many more sensations. what are these sensations?
- Abeta: touch
- Adelta + C: pain & thermal
- Adelta: taste
all oral epithelium is what type of epithelium?
stratified squamous epithelium
*cell division occurs in deep layers and the superficial layers are sloughed off
does the oral mucosa have a fast or slow turnover time?
fast
- speeds healing
- leaves tissue more vulnerable to conditions that affect cell division like chema and radiotherapy
the volume of the oral EPITHELIUM is occupied by ____
cells
- keratinocytes are most numerous
- Non-keratinocytes: Merkel cells, melanocytes, langerhans
what are the 3 non-keratinocytes of the oral EPITHELIUM?
- merkel cells–sensory–basal layers
- melanocytes–pigment cells–basal layers (clear)
- langerhan cells–immune–SUPRA basal layers (clear)
*langerhan cells are more superficial than melanocytes, both are clear
from superficial to deep, what are the 4 layers of the keratinized epithelium vs the non-keratinized epithelium
keratinized: TOUGHER AND MORE IMPERMIABLE
- keratinized layer
- granular layer
- prickel cell layer
- basal cell layer
non-keratinized: MORE FLEXIBLE
- superficial layer
- intermediate layer
- prickel cell layer
- basal cell layer
all oral EPITHELIAL CELLS contain ______ which assemble into ______ providing cytoskeletal support (resist mechanical support w/o breaking
- cytokeratins
- intermediate filaments
- two major groups: type I (acidic) and type II (basic)
- different epithelial layers and tissues contain different cytokeratins
cytokeratins are the intracellular component of what?
desmosomes and hemidesmosomes
mutations in cytokeratins 5/14 (basal layer) leads to what?
epidermolysis bullosa simplex (EB simplex)
- rare, blistering in response to minor trauma
- most severe in epidermis but also oral consequences
mutations in cytokeratins 4 & 13 can produce regionally specific diseases such as ___
white sponge nevus
-affects oral non-keratinized epithelia
what are the fxns of cytokeratins in keratinized vs non-keratinized epithelium?
keratinized:
- promotes aggregation (tonofibrils)
- promote binding to another molecule (fillagrin)
non-keratinized:
- do not promote aggregation
- cannot complex with fillagrin
what are membrane coating granules?
*found in both keratinized and nonkeratinized epithelium but much more pronounced in keratinized (loricin)
- membrane bound organelles filled w glycolipids
- 1rst appear in upper prickle cell layers
- released more in superficial layer to coat cell
- INTERcellular barier to AQUEOUS substances
- effective barrier in keratinzed epithelium
most of the volume of the lamina propria is occupied by the ____
ECM
- cells also present
- ECM contains ELASTIN!!! (not found in pulp or PDL)
the relative amount of type I: type III collagen is GREATER for _____ regions of the oral cavity
less flexible
how is the epithelium connected to the lamina propria?
papillary and reticular layers
present under some regions of oral mucosa, contains lager blood vessels and nerves supplying superficial LP. also contains glands and separates LP from bone and m
submucosa
where are the locations of masticatory mucosa vs lining mucosa
masticatory mucosa:
-gingiva & hard palate
lining mucosa
- underside of tongue
- floor of mouth
- alveolar mucosa
- soft palate
what is the only part of the lip region that is keratinized?
vermillion zone
part of the free gingiva which faces tooth, generally non-keratinized
sulcular epithelium
forms seal with hard tissue tooth (enamel/cementum) and is HIGHLY PERMEABLE
junctional epithelium
- contains two basal lamina (external and internal)
- collagen components are absent in the internal BL
despite its specialized nature, jxn epithelium can regenerate how?
relatively rapid and also occurs around dental implants
