Epithelial Cells (Locations, Purposes, Parts, Junctions) Flashcards
Where is epithelial tissue found
Body surface and lining of hollow organs, cavities and ducts, as well as forming certain glands
What are the purposes of epithelial tissue
Limiting or aiding transfer, secretion onto a free surface, protection from abrasion
What are the two different cytoskeleton components
Actin Microfilaments and Keratin Intermediate Filaments
Microfilaments are predominantly composed of…
Actin
Intermediate filaments are predominantly composed of…
Keratin
What do microfilaments do?
Provide shape and strength to the cell and initiate cell movement
What do intermediate filaments do?
Provide shape and strength to the cell and move material around the cytoplasm
How do tight cell junctions hold cells together?
They “stitch” them together near the apical end of the cell with claudin and occludin
Will a tight cell junction allow for ions to pass between cells?
No, they are electrically tight
What are tight cell junctions made out of?
Claudin and Occludin
The gap within an adherence cell junction is spanned by what protein?
Cadherin
____ helps ____ bind to ____ ____in an adherence cell junction
Catenin helps bind Cadherin to Actin Microfilament in an adherence cell junction
A gap cell junction is formed by a combination of six ____ to form one ____ between cells
A gap cell junction is formed by a combination of six connexins to form one connexon/hemichannel between cells
Gap junctions form ___ between cells which allow transfer between cells
Gap junctions form tunnels between cells which allow transfer between cells
Desmosomes cell junctions look like what?
Buttons
The gap within a desmosome cell junction is spanned by what protein?
Cadherin
___ links to ___ ___ ___ in a desmosome cell junction
Cadherin links to keratin intermediate filaments in a desmosome cell junction
Hemidesmosome cell junctions bind to what membrane?
The basement membrane
Hemidesmosome cell junctions look like what?
Buttons
Hemidesmosome cell junctions bind to what cytoskeleton component?
Keratin intermediate filaments
The gap between the basement membrane and a hemidesmosome button are bridged by what?
Integrin
What does a hemidesmosome cell junction bind to in the basement membrane
Laminin
Epithelial cells anchor to the ___
Basement membrane
The basement membrane is comprised of ___ lamina and ___ lamina
Basal lamina and Reticular lamina
The basal lamina is made from proteins supplied by ___
Epithelial cells
Which produce collagen, laminin, proteoglycans, glycoproteins etc.
The reticular lamina is made from fibrous proteins supplied by ___
Fibroblasts in the connective tissue (Which produce fibronectin, collagen etc.)
Do epithelial cells bind to the basal lamina or the reticular lamina?
Basal lamina
Can epithelial tissue contain blood vessels?
No
Can epithelial tissue contain nerves?
Yes
How do epithelial cells gain nutrients and dispel waste?
The nutrients and waste diffuse into and out of epithelial cells through the basement membrane
