Intercalated disc

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Intercalated disc
Cardiac muscle, an intercalated disc can be seen joining cardiomyocytes in magnified section
Latin Discus intercalaris, discus intercalatus
Code TH H2.
Anatomical terminology

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.

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.


  1. ^ Franke WW, Borrmann CM, Grund C, Pieperhoff S (February 2006). "The area composita of adhering junctions connecting heart muscle cells of vertebrates. I. Molecular definition in intercalated disks of cardiomyocytes by immunoelectron microscopy of desmosomal proteins". Eur. J. Cell Biol. 85 (2): 69–82. doi:10.1016/j.ejcb.2005.11.003. PMID 16406610. 
  2. ^ Goossens S, Janssens B, Bonné S, et al. (June 2007). "A unique and specific interaction between alphaT-catenin and plakophilin-2 in the area composita, the mixed-type junctional structure of cardiac intercalated discs". J. Cell. Sci. 120 (Pt 12): 2126–36. doi:10.1242/jcs.004713. PMID 17535849. 
  3. ^ Pieperhoff S, Barth M, Rickelt S, Franke WW (2010). "Desmosomal molecules in and out of adhering junctions: normal and diseased states of epidermal, cardiac and mesenchymally derived cells". In Mahoney MG, Müller EJ, Koch PJ. "Desmosomes and desmosomal cadherin function in skin and heart diseases-advancements in basic and clinical research". Dermatol Res Pract 2010. doi:10.1155/2010/725647. PMC 2946574. PMID 20885972. 

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