In some animal tissues the cell-cell adhesions which are set up during the embryonic development are followed by the forming of intercellular junctions. Cell junctions are large, complex structures which are built by the cooperating activities of many separate molecules. Parts of the desmosomes The plaque region lies just under the plasma membrane on either side of the junction.
Intermediate filaments extend from the plaque for some distance into the underlying cytoplasm.
They could be from one of two types, cytokeratin or vimentin. The membranes of the cells sharing the desmosome are parallel and separated by a regular distance in the region of the junction. This space, called the core of the desmosome, is filled with filaments and granular molecules. Half desmosomes, also referred to as hemidesmosomes , occur where cells are anchored to extracellular materials. They also appear along the plasma membrane in cells which are grown in tissue culture, where they anchor cells to the glass or plastic substrate which they are grown on.