Oral Mucosa Flashcards
mucous membrane
organ composed of 2 tissues:
epithelium overlying CT (lamina propria and SOMETIMES submucosa)
**much like skin with epidermis, dermis and hypodermis
where are blood vessels in the mucous membrane?
lamina prop/ and maybe submucosa
where are the minor salivary glands in the mucous membrane?
mainly submucosa/ sometimes lam prop
**major salivary gland ducts go through the CT, but are more removed from the oral cavity
what lymphoid tissue is in the oral mucosa?
lingual, palatine and pharyngeal tonsils
what are the functions of oral mucosa?
- barrier (epi>lam) (physical barrier)
- protection (lam>epi)
- ingestions - flexibility and moist surface for chewing and swallowing
antimicrobial capabilities of epithelial cells
beta-defensins are secreted normally but increase in number and types when invasion occurs. They are cysteine rich (+) to bind to negative charges on bacteria
**antimicrob best seen in gingiva
sensory fibers in the oral mucosa compared to the pulp and PDL
pulp (C) and dentin (A delta) and A beta and mainly only feel pain. PDL the C and Adelta fibers feel pain and Abeta is propriocep. In the oral mucosa the A beta does light touch, the Adelta and C do pain and thermal sensation and the A delta MAY do taste??
what kind of epithelium does all the oral mucosa have?
stratified squamous epi
turnover times of epithelium
- *self renewal b/c the deep layers do cells division and the superficial layers migrate, mature and get sloughed off after desmosomes break
- keratinized structures like gingiva have a slower rate than unkerat like B and L mucosa of the cheek, taste buds and junctional epi
is fast turnover good or bad?
both
can speed the healing process, but cells more vulnerable to conditions that affect cell division (ex. chemo)
make up of oral epithelium
-most of the volume is cells (keratinocytes) but also non-ketat like merkel cells, melanocytes and langerhans
merkel cells
sensory, in the basal epithelium
melanocytes
pigment, in basal epithelium - clear
*contains melanin to give oral mucosa color based on the breakdown
langerhans
(dendtritic cells) of immune system, superficial basal epi - clear
difference in layers of the kerat vs. unkerat epi
- keratinized distinct clinical appearance from unkerat
- granular in kerat and intermediate in unkerat
- keratinized layer has no organelles, dehydrated and tougher and the superficial layer has organelles and is flexible
cytokeratins
all epithelial cells (keratinocytes) have cytokeratins
-large family of genes, assembles into intermediate filaments to provide support to the cytoskeleton (2 types)
structure of intermediate filaments
type 1 (acidic) and type II (basic) - 2 major groups -cytokeratins have helical center, non-helic ends that (type I and II cytokeratins expressend in each). Coil into a heterodimer to make an intermediate filament
special property of intermediate filaments in epithelium
resist mechanical forces without breaking
**intracellular component of desmosomes and hemidesmosomes
mutations in cytokeratins
5/14 (basal layer) leads to epidermolysis bullosa
-rare, blistering in response to minor trauma, oral and non oral consequences