Epithelia Flashcards
What are epithelial cells?
Cells that cover or lone all the body surfaces, tubes and cavitiesCells that form the interfaces between different physiological fluid compartments
What do all epithelial cells stand on?
The basement membrane
What are tumours called if they develop from epithelial cells?
Carcinomas
What connects epithelial cells that are in intimate contact?
Tight junctions
Why do epithelial cells have to undergo rapid division?
Cells are being constantly lost from the surface
What are the three shapes of epithelial cells?
Columnar
Cuboidal
Squamous
What is the columnar shape split into?
Apex- next to the lumen
Base-basal part of the cell
What is unique about squamous epithelial cells?
They have the appearance of a flattened sheet
How can epithelial cells also be structured?
By stratified, more than one layer
What are the benefits of a single layer of epithelial cells?
All cells in direct contact with the lumen and BM
Quicker diffusion or absorption
What are the benefits of a stratified layering?
Greater protection from abrasion, infection or caustic content
What are epithelial cells called if they are in contact with the BM in a stratified system?
Basal
What are epithelial cells called if they are in contact with the lumen in a stratified system?
Apical
How can stratified cells also be arranged?
With a mixture of columns, cuboidal and squamous
Where will you find a simple squamous structure?
Blood vessels