BL - Integrating Cells Flashcards
How long can packed red cells be stored at 6 degrees C for?
42 days
What is found between adjacent epithelial cells?
Cell junctions
What is the function of a cell junction?
They ensure that cells are tightly adhered to one another.
What are the three types of cell junction?
Tight junctions, desmosomes and gap junctions
How do tight junctions attach cells together?
They fuse the plasmalemma.
What is the function of a tight junction?
They form an impenetrable barrier so molecules cannot pass between the two cells (and must pass through the cell instead). This allows them to act as a “security guard”.
Give an example of where tight junctions can be found.
In the epithelial lining of the intestine.
True or false - desmosomes are often found very close to tight junctions?
True
Where are desmosomes often found?
Between epithelial cells that often undergo abrasion, eg in the skin.
Which type of cell junction involves proteins that interlock between epithelial cells?
Desmosomes
What is the function of a gap junction?
They allow cells to communicate with each other.
What are connexons?
Small channels (proteins) that allows ions and small molecules to pass between cells so they can communicate.
What is the basement membrane?
The structural site and point of attachment for overlying cells and underlying connective tissue.
In what two ways can cells attach to the basement membrane?
Hemidesmosomes or focal adhesions
What is the difference between a hemidesmosome and a desmosome?
Hemidesmosomes attach cells to the basement membrane, desmosomes attach cells to cells.