Junctions Flashcards
What type of junction seals epithelial sheets?
Occluding / tight
Tight junctions between epithelial cells…
Prevent diffusion of proteins + and ALL ions and large molecules across the epithelium.
Name a protein found within tight junctions.
Occludin
What functions are performed by Tight Junctions of the gut epithelium?
Prevent passage of molecules between cells
Enable specialisation of different regions of the plasma membrane
Hold cells together
Adherens junctions and desmosomes link …
Hemidesmosomes and focal adhesions link …
Cell to cell
Cell to ECM
Transmembranous proteins in anchoring junctions:
… is found in adherens junctions and desmosomes
… is found in hemidesmosomes and focal adhesions
Cadherin
Integrin
What components of the cytoskeleton are linked by the following anchoring junctions:
Adherens junctions + focal adhesions?
Hemidesmosomes + Desmosomes?
Actin
Intermediate filaments
What functions are performed by desmosomes and hemidesmosomes?
Give epithelia mechanical strength
Resist shearing forces
Rivet cells to one another AND the ECM
Adherens junctions link the cytoskeletons of Cardiac muscle cells. True or false?
True!
A type of junction common in cardiac muscle tissue is…
Gap Junction
Gap junctions are made up of proteins of the … family.
The structure formed (called a …) is a transmembranous …
Two of these structures come together to form a … linking the cytoplasm of the two cells.
Connexin
(ConnexON)
Ring
Channel
Which of the following CAN pass through gap junctions?
Ions
Secondary messengers such as cyclic (c)AMP
METABOLITES (sugars, amino acids)
In epithelia containing ion pumping cells, back diffusion is PREVENTED by the presence of…
Tight Junctions
