Mucous Membranes Flashcards
The mouth is lined by a moist ___ membrane.
mucous
The mucous membrane is an organ composed of what 2 tissues?
epithelium and connective tissue
Which tissue does not contain blood vessels or salivary glands?
epithelium
Connective tissues consist of a ___ ___ and sometimes a submucosa. Both layers contain ___ ___ but minor ___ glands are mostly found in the submucosa.
lamina propria; blood vessels; salivary
___ from both major and minor salivary glands travel thru connective tissue to communicate with the mucosal surface.
Ducts
What other tissue is found embedded in the oral mucosa?
lymphoid tissue
-lingual and palatine tonsils
Which layer of the mucous membrane is the better barrier for protections, epithelium or basal lamina?
epithelium
What two cells are involved in the anti-microbial protection of the mucous membrane?
immune cells and epithelial cells
In addition to the tonsils, which cell type is found mainly in the lamina propria?
immune cells
Epithelial cells synthesize and secrete several antimicrobial molecules. Name one important example.
beta-defensins
When the mucous membrane is invaded by pathogenic bacteria, different varieties of ___-___ are secreted in different layers of the epithelium.
beta-defensins
Beta-defensins are ___-rich and cationic. They bind to ___ charges on bacterial membranes and cause them to ___.
cysteine; negative; permeabilize
Another function of the mucous membrane is ingestion due to what properties?
its flexibility and moist surface
T/F. The oral mucosa is not highly innervated.
False, the oral mucosa IS highly innervated and this augments protective and ingestive functions
Which tissue is capable of more types of sensations, dentin/pulp, PDL or oral mucosa?
oral mucosa
What fibers are associated with pain in the dentin and pulp?
C, A-delta, A-beta
What are the two sensations found in the PDL?
C and A-delta = pain
A-beta = proprioceptive
Match the fibers of the oral mucosa with their sensations.
A. A-beta
B. A-delta
C. C
- touch
- pain
- thermal
- taste
A - 1
B - 2, 3, 4
C - 2, 3
What type of epithelium is found in all types of oral epithelium?
stratified squamous epithelium
The epithelium has an ability to self-___. The deep layers are involved in ___ ___. The superficial layers migrate and once matured they are ___ off.
renewal; cell division; sloughed
T/F. Relatively fast turnover can speed healing, but also can make tissues more vulnerable to conditions that affect cell division (chemotherapy & radiotherapy).
True.
Most of the volume of the epithelium is occupied by ___. Which cell is the most numerous?
cells; keratinocytes
Give some examples of non-keratinocytes found in the epithelium.
Merkel cells - sensory - basal layer
Melanocytes - pigment cells - basal layer
Langerhan (dendritic) cells - immune - supra-basal layers
Which non-keratinocytes are better known as clear cells?
Melanocytes and Langerhan (dendritic) cells
How can you distinguish langerhan cells from melanocytes if they both appear clear upon H&E staining?
location
What do clear cells lack when stained?
cytokeratin
Special staining reveals that melanoctes have a cell body with processes located in which layer?
basal layer
Langerhan cells are similar in structure to melanocytes but where are they found?
suprabasal layer
T/F. Keratinized and non-keratinized epithelium have the same clinical appearance.
False, they have distinctive clinical appearances.
Microscopic characteristics of both keratinized and non-keratinized epithelium contain a ___ layer and ___ cell layer.
basal; prickle (stratum spinosum)
T/F. The superificial layers between keratinized and non-keratinized epithelium is distinct.
True.
Keratinized epithelium contains no ___ , is ___ and has a tough appearance. Whereas, the ___ layer is otherwise flexible and contains organelles.
organelles; dehydrated; superficial
All epithelial cells = ___ and contain ___.
keatinocytes; cytokeratins
Cytokeratins assemble into ___ ___ to provide cytoskeletal support. What are the two types?
intermediate filaments; type I (acidic) and type II (basic)
Mutations in cytokeratins cause what disease?
Epidermolysis bullosa simplex (EB simplex)
It is rare, and has characteristic blistering in response to minor trauma. It is most severe in the epidermis but also has oral consequences.
Different epithelial ___ and ___ contain characteristic cytokeratins.
layers; tissues
T/F. Cytokeratin expression remains the same in normal and disease states. But, mutations in cytokeratin genes can produce regionally-specific diseases.
False, cytokeratin expression CAN change with disease state
True, mutations in cytokeratin genes produce regionally specific diseases.
Different ___ types are important for ___ properties of keratinized vs non-keratinized epithelia. In both, the ___ of cytokeratin ___ in superficial layers.
cytokeratins; mechanical; amount; increases
How do keratinized cytokeratins promote aggregation?
thru the formation on tonofibrils found in the prickle layer
How do keratinized cytokeratins promote binding to another molecule?
with fillagrin, a main component of keratohyalin granules - found in the granular layer.
Describe the superficial layer of keratinized epithelium.
very flat cells
dehydrated
no organelles
packed with cytokeratin (tonofibril) / filligrin complexes
T/F. In non-keratinized epithelium, cytokeratin does not promote aggregation and cannot complex with fillagrin but the superficial layers are flat, dehydrated and retain nuclei and cytokeratin tonofilaments.
False, In non-keratinized epithelium, cytokeratin does not promote aggregation and cannot complex with fillagrin but the superficial layers are NOT flat OR dehydrated and retain nuclei and cytokeratin tonofilaments.
T/F. Non-keratinized epithelium is tougher but less flexible than keratinized epithelium.
False, KERATINIZED epithelium is tougher but less flexible than NON-keratinized epithelium.
What are membrane bound organelles filled with?
glycolipids
Membrane coating ___ first appear in the upper ___ cell layers and are released in more ___ layers to coat cells. This occurs in both epithelium and serves as an ___ barrier to aqueous substances.
granules; prickle; superficial; INTERcellular
Differences in chemical composition creates ___ (> /
>
A ___ envelope is a 15nm cross-linked protein sheath comprised of ___ and other proteins.
cornified; loricrin
Most of the volume of the lamina propria is occupied by ___ that contains type ___ and type ___ collagen and ___.
ECM; type I; type III; elastin
T/F. The relative amount of type I : type III collagen is greater for less flexible regions of the oral cavity.
True.
___ is more prominent in the oral mucosa than in pulp or PDL.
elastin
Connective tissue ___ are scalloped with ___ ___ between the convoluted ____ layer of the epithelium and ___ layer of the lamina propria.
papillae; rete pegs; papillary; reticular
What separates the lamina propria from bone and muscle?
submucosa
List some structures that do not have any submucosa.
lp-muscle, tongue, lp-bone (mucoperiosteum), gingiva, hard palate next to gingiva, rugae region, median raphe
The lining mucosa has ___ epithelium and is found where?
non-keratinized; buccal and labial mucosa and floor of mouth
What are the clinical implications of the lining mucosa?
incisions more likely to gap and need to be sutured. injections are less painful
Which structures are thin and have keratinized epi, exterior skin, vermillion zone, or labial mucosa?
exterior skin and vermillion zone
What type of glands are found in the following: exterior skin, vermillion zone, and labial mucosa?
exterior skin - sweat glands
vermillion zone - no sweat or mucous glands
labial mucosa - mucous glands
Which mucosa has fewer collagen fibers and more elastic fibers, the masticatory or lining mucosa?
lining,mucosa has more collage fibers and fewer elastic fibers
What are the clinical implications of the masticatory mucosa?
incisions don’t gape, may not require suturing, injections are more painful
The sulcular and junctional epithelium are part of the ___.
periodontium
The sulcular epithelium is part of the ___ gingiva which faces the tooth and generally has ____ epithelium.
free; non-keratinized
T/F. The junctional epithelium is highly permeable leading it susceptible to inflammation.
True.
Which junctional epitelium has type IV and VII epithelium, external (JE/lamina propria) or internal (JE/tooth)?
internal
Collagen components of the ___ ___ provide direct connection to collage of lamina propria.
basal lamina
Consistent with it’s origin from ___ ___ ___, JE expressed a protein initially associated with ameloblasts.
reduced enamel epithelium
T/F. The “col” is also characterized by JE.
True.
T/F. Despite its specialized nature, JE can regenerate relatively rapidly and around dental implants.
True.
How does the vascular supply get to the gingiva?
superior alveolar / palatine AND inferior alveolar/buccal/mental/sublingual feed into the PDL, interdental septa and oral mucosa then to the gingiva
