Intercalated discs or lines of Eberth 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
syncytium. By contrast, skeletal muscle consists of
multinucleated muscle fibers and exhibits no intercalated discs. Intercalated discs support synchronized contraction of cardiac tissue in a wave-like pattern so that the heart can work like a pump.[1] They occur at the Z line of the
sarcomere and can be visualized easily when observing a longitudinal section of the tissue.
Desmosomes prevent separation during contraction by binding
intermediate filaments, anchoring the cell membrane to the intermediate filament network, joining the cells together. [2][3]
Gap junctions connect the cytoplasms of neighboring cells electrically allowing
cardiac action potentials to spread between cardiac cells by permitting the passage of ions between cells, producing
depolarization of the heart muscle.[3][2]
All of these junctions work together as a single unit called the area composita.[2]
^ This article incorporates
text available under the
CC BY 4.0 license. Betts, J Gordon; Desaix, Peter; Johnson, Eddie; Johnson, Jody E; Korol, Oksana; Kruse, Dean; Poe, Brandon; Wise, James; Womble, Mark D; Young, Kelly A (June 8, 2023). Anatomy & Physiology. Houston: OpenStax CNX. 10.7 Cardiac muscle tissue.
ISBN978-1-947172-04-3.
^
abcdeZhao, G; Qiu, Y; Zhang, HM; Yang, D (January 2019). "Intercalated discs: cellular adhesion and signaling in heart health and diseases". Heart Failure Reviews. 24 (1): 115–132.
doi:
10.1007/s10741-018-9743-7.
PMID30288656.
S2CID52919432.
^Page 38 in: Giorgio Baroldi (2004). The Etiopathogenesis of Coronary Heart Disease: A Heretical Theory Based on Morphology, Second Edition. CRC Press.
ISBN9781498712811.
^
abPage 55 in: Vittorio Fineschi, Giorgio Baroldi, Malcolm D. Silver (2016). Pathology of the Heart and Sudden Death in Forensic Medicine. CRC Press.
ISBN9781420006438.{{
cite book}}: CS1 maint: multiple names: authors list (
link)
^
abFineschi, Vittorio; Karch, Steven B.; D'Errico, Stefano; Pomara, Cristoforo; Riezzo, Irene; Turillazzi, Emanuela (2005). "Cardiac pathology in death from electrocution". International Journal of Legal Medicine. 120 (2): 79–82.
doi:
10.1007/s00414-005-0011-8.
ISSN0937-9827.
PMID16078070.
S2CID24759863.
External links
Histology image: 22502loa – Histology Learning System at Boston University — "Ultrastructure of the Cell: cardiac muscle, intercalated disk "