Cell Junctions

Tight Junction

• no extra cellular space/extra cellular space between cells is blocked

• This enables the epithelia to act as selective barriers

tight junction

Separated the cells into apical and basal compartments

Adherents

• used either cadherins or integrins depending on whether they are linking to other cells or matrix

• Cadherins = cells

• Integrins = matrix

Hemidesmosomes

• look like half a desmosome

• Link to extra cellular matrix

• Include adhesion protein integrins

Desmosomes

• occur in patches on the membrane of cells

• Adhesion molecule cadherin is embedded in the patches

Gap Junction

This junction allows electrical and metabolic coupling of adjacent cells, which coordinates function in large groups of cells

Gap Junction

Forms an intercellular passageway between the membranes of adjacent cells to facilitate the movement of small molecules and ions between the cytoplasm of adjacent cells