noun, plural: cell junctions
Intercellular connections between adjacent cells, resulting in varying degrees of fusion and specialized functions of animal tissues
Cell junctions are intercellular connections between the plasma membranes of adjacent cells of animal tissues. They are formed by multiprotein complexes that provide contact between adjacent cells or between a cell and the extracellular matrix. There are three major types of cell junctions: (1) tight junctions, (2) gap junctions, and (3) anchoring junctions (e.g. desmosomes).
Tight junctions are a type of cell junction formed between epithelial cells of vertebrates wherein the outer layers of two adjacent cells fuse, thereby serving as a barrier to the passage of fluid between cells.
Gap junctions are cell junctions characterized by the intercellular channel that is formed between neighboring cells that allow direct communication between cells. Small molecules, ions, and electrical impulses are allowed to move between cells without passing the outside of cells.
Anchoring junctions are cell junctions that are anchored to one another and attached to components of the extracellular matrix. Examples of anchoring junctions are desmosomes, hemidesmosomes, and adherens junctions. They are important in keeping the cells together and structural cohesion of tissues.
- intercellular junction
- intercellular bridge