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Cardiac Muscle Structure. Diagram of cardiac muscle cells indicates characteristic features of this muscle type. The fibers consist of separate cells with
interdigitating processes wherein they are held together. These regions of contact are called the intercalated disks (IDs), which cross an entire fiber
between two cells. The transverse regions of the step-like ID have abundant desmosomes and other adherent junctions, which hold the cells firmly
together. Longitudinal regions of these disks contain abundant gap junctions, which form “electrical synapses” allowing contraction signals to pass from
cell to cell as a single wave. Cardiac muscle cells have central nuclei and myofibrils that are less dense and organized than those of skeletal muscle. Also
the cells are often branched, allowing the muscle fibers to interweave in a more complicated arrangement within fascicles that produces an efficient
Source: Chapter 12. Muscles and Motility, The Big Picture: Medical Biochemistry
contraction mechanism for emptying the heart. [Reproduced with permission from Mescher AL: Junqueira's Basic Histology Text and Atlas, 12th edition,
McGraw-Hill,Citation:
2010.] Janson LW, Tischler ME. The Big Picture: Medical Biochemistry; 2012 Available at: http://mhmedical.com/ Accessed: May 09, 2017
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