Cell junctions join cells in some biological tissues.
They have long protein chains, The proteins keep connections between neighbouring cells or between a cell and other structures. They also control substance transport outside cell surfaces.
Vertebrates have three main types of cell junction:
- Adherens junctions: holds cells together and provides tissues with structural support. They are common where mechanical stress occurs eg. skin or heart
- Gap junctions: allows for chemical communication between neighbouring cells
- Tight junctions: regulate movement of water and liquids between epithelial layers
