cell junctions Flashcards
Epithelium:
tissues that line a void in the body
what do epithelial cells tend to rest upon?
basal lamina
Basal lamina
specialized form of extracellular matrix with collagen, elastin, that have been secreted by these cells which they then anchor themselves to.
what are the three classes (by function) of cellular junctions?
- sealing 2. adhesion 3. communiction
what kind of junctions in cells seal things together?
tight junctions
what kind of junction sits just below one other junction, run through cells in bundles of actin filaments, and attaches the cytoplasm to the actin cytoskeleton?
adherens junction
what is the velcro like protein in adherens junctions called?
cadherin
what are all the types of adhesion junctions?
adherins, desmosomes, hemidesmosomes
what do desmosomes do
help hold cells together by linking cell surface to keratin cytoskeleton.
what protein do desmosomes use to do their job
The cell adhesion proteins of the desmosome, desmoglein and desmocollin, are members of the cadherin family of cell adhesion molecules.
hemidesmosomes- what are they are where are they located?
perched on top of the basal lamina, hemidesmosomes are rivet-like structures that attach one cell to the extracellular matrix.
what protein is associated with desmosomes?
keratin
what is a gap junction and what does it do?
alllows the passage of small water soluble ions and molecules in the cytosol. responsible for cellular communication
what are connexons and where are they used?
Gap junctions create a channel for communication by using connexon proteins.
where would you find gap junctions?
Common in cardiac muscle intercalated discs, smooth muscle and other places – allows ion and small signal molecule exchange
