Intercalated discs

Intercalated disc
Cardiac muscle, an intercalated disc can be seen joining cardiomyocytes in magnified section
Latin Discus intercalaris, discus intercalatus
Code Template:TerminologiaHistologica

Intercalated discs are microscopic identifying features of cardiac muscle. Cardiac muscle consists of individual heart muscle cells (cardiomyocytes) connected by intercalated discs to work as a single functional organ or syncytium. By contrast, skeletal muscle consists of multinucleated muscle fibers and exhibit no intercalated discs. Intercalated discs support synchronised contraction of cardiac tissue. They occur at the Z line of the sarcomere and can be visualized easily when observing a longitudinal section of the tissue.

Three types of adhering junctions make up an intercalated disc — fascia adherens, macula adherens and gap junctions.

However, molecular biological and comprehensive studies have shown that intercalated discs consist for the most part of mixed type adherens junctions termed composite junctions or areae compositae (singular area composita). These represent an amalgamation of typical desmosomal and fascia adherens proteins (in contrast to various epithelia).[1][2][3] Thus cardiomyocyte adherens junctions differ from epithelial zonula adherens and desmosomes.

See also

External links

  • eMedicine Dictionary
  • 22502loa — "Ultrastructure of the Cell: cardiac muscle, intercalated disk "

References