oral mucosa structure Flashcards
what types of oral muccosa are there? and where do they line?
- Masticatory mucosa
- (15% of total area)
- Lining mucosa
- (60% of total area)
- Specialised mucosa
- (25% of total area)
what are the layers in epithelium during epithelium renewal?
what cells does the basal layer of epithelium contain? and what functions do they have?
Progenitor –
- amplifying cells for differentiation
Stem cells –
a division to produce a daughter cell and a progenitor
- Stem cells can renew themselves and form progenitor cells for differentiation
what is turnover speed of epithelium controlled by?
- locally produced cytokines/growth factors
describe the basal layer of oral epithelium
- Single layer on basal membrane
- Cuboidal or Columnar
- Interface of epithelia and lamina propria
- Contains most mitotic cells
- Precursor (proliferation and differentiation)
- Stem cells (Less proliferation and producing daughter cells)
- Producing K5 and K14
describe the spinous layer of oral epithelium
- Many cells thick
- Polyhedron like
- Cell proliferation close to basal layer
- Cells connections (Prickles)
- Cells have prickles on cell surface to connect cells
- Tonofibrils attached to desmosomes
- Keratins produced as non-secreted and insoluble proteins (K1, K6, K10, K16)
describe the granular layer of the oral epithelium
keratinised
- >3-5 cells thick
- Cells are flattened
- Highly keratins aggregated with tonofillaments to form tonofibrils bundles
- Intracellular fibre bundles
- Membrane-coating glycolipid form elongated granules
- More Cytokeratins accumulated on cell membranes
- Protein cross linked by TG1, 3 and 5
- Transglutamine 1 , 2 , 5
describe the keratinised layer of the oral epithelium
- Away from nutrients supply
- More flattened dead cells
- Lost cell nuclear and granules
- Full of keratin fibre through out the cells
- Wear off
what keratins are in non-keratinised epeithelium?
K5, K14, K19 and K4, K13
what keratins are in keratinised epithelium?
K5, K14 and K1, K2, K6, K10, K16
compare the composition of keratinised and non-keratinised epithelium?
how are epithelial cells connected?
- tight junctions
- gap junctions
- desmosomes
characteristics of tight junctions
- impermeable junctions
- prevents proteins passing through intercellular space
- uses ocludin, claudin and junctional adhesion molecules to seal intercellular space
characteristics of gap junctions
- has intercellular channels
- allows small molecules to transport to neighbour cells
- channel is made by 6 connecting proteins
characteristics of desmosomes
- connection used in protein anchoring