Epithelium Flashcards
What 3 distinct areas is the oral mucosa split into?
- Epithelium
- Connective Tissue or lamina propria
- Sub-mucosa
Epithelial Cell shape and structure photo:
How are epithelial cells classified number of layers?
How are epithelial cells classified depeing on shape of cell?
Epithelial cell classification
What can stratified squamous epithelium be divided into?
- Masticatory oral mucosa- (gingival and hard palate)- keratinising
- Lining oral mucosa- (floor of mouth, buccal regions and oesophagus)- non keratinising.
- Specialised (the dorsum of the tongue)- both.
What is the Function of oral mucosa epithelium?
- Protection of underlying tissue
- The different epithelium form lipid based permeability barriers.
- Protect from fluid loss
- Protect from ingress of potentially harmful environmental agents.
What is cell prolieration?
An increase in the number of cells; as a result of cell growth and cell division.
How does a cell divide?
A cell reproduces by performing an orderly sequence of events in which it duplicates its contents and then divides in two.
What is the definition of a ; Growth factor & Transcription factor?
Growth factor- polypeptides that control animal cell growth and differentiation. Usually produced near where they act. Can be stored and released by ECM.
Transcription factor- a protein that regulates the activity of RNA polymerase
What happens with proliferation of Stem cells?
- Not terminally differentiated
- Divide without limit
- When divides, each daughter cell has choice-
What does Differentiation mean?
The process by which cells or tissues undergo change toward a more specialised form or function.
How do cells stop dividing and differentiating?
Equilibrium cells removed from surface and replaced from behind.
Removal of intergrin expression.
What is the Cytoskeleton-definition?
- System of protein filaments in the cytoplasm of a eukaryotic cell that gives the cell shape and the capacity for directed movement.
- Most abundant components: actin filaments, microtubules and intermediate filaments.
What must cells have to be able to do?
- Organise themselves in space and interact mechanically with their environment.
- Be correctly shaped, physically robust and properly structured internally.
- Be able to change shape, move from place to place.
- Be able to rearrange internal components as they grow, divide, adapt to changes.
- Spatial and mechanical functions are developed to high degree in eukaryotic cells.
What are Intermediate filaments?
- Ropelike fibres diameter around 10nm.
- Made of intermediate filament proteins.
- One group forms nuclear lamina.
- Others extend across the cytoplasm giving mechanical strength.
- In epithelial tissue, span the cytoplasm from one cell-cell junction to another, strengthening the entire epithelium.
