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Nov 23, 2022 · Cardiac muscle fibers are long, branched cells, shaped like cylinders joined end-to-end, with one or two nuclei located centrally. The fibers are separated by collagenous tissue that supports the capillary network of cardiac tissue.
- Medical Content
- 14 min
Cardiac muscle fibers have a single nucleus, are branched, and joined to one another by intercalated discs that contain gap junctions for depolarization between cells and desmosomes to hold the fibers together when the heart contracts.
- OpenStaxCollege
- 2013
However, cardiac muscle fibers are shorter than skeletal muscle fibers and usually contain only one nucleus, which is located in the central region of the cell. Cardiac muscle fibers also possess many mitochondria and myoglobin, as ATP is produced primarily through aerobic metabolism.
- Dilated Cardiomyopathy
- Hypertrophic Cardiomyopathy
- Restrictive Cardiomyopathy
- Arrhythmogenic Right Ventricular Dysplasia
- Transthyretin Amyloid Cardiomyopathy
Dilated cardiomyopathy causes the cardiac muscle tissue of the left ventricle to stretch and the heart’s chambers to dilate.
Hypertrophic cardiomyopathy (HCM) is a genetic condition in which the cardiomyocytes are not arranged in a coordinated fashion and are instead disorganized. HCM can interrupt blood flow out of the ventricles, cause arrhythmias (abnormal electrical rhythms), or lead to congestive heart failure.
Restrictive cardiomyopathy (RCM) refers to when the walls of the ventricles become stiff. When this happens, the ventricles cannot relax enough to fill with an adequate amount of blood.
This rare form of cardiomyopathy causes fatty infiltration in cardiac muscle tissue in the right ventricle.
Transthyretin amyloid cardiomyopathy (ATTR-CM) develops when amyloid proteins collect and form deposits in the walls of the left ventricle. The amyloid deposits cause the ventricle’s walls to stiffen, which prevents the ventricle from filling with blood and reduces its ability to pump blood out of the heart. This is a form of RCM.
Jul 30, 2023 · The sarcolemma of cardiac muscle cells contains voltage-gated calcium channels, specialized ion channels that skeletal muscle does not possess. Cardiac muscle cells contain branched fibers connected via intercalated discs that contain gap junctions and desmosomes.
- 2023/07/30
Aug 8, 2023 · The individual cardiac muscle cell (cardiomyocyte) is a tubular structure composed of chains of myofibrils, which are rod-like units within the cell. The myofibrils consist of repeating sections of sarcomeres, which are the fundamental contractile units of the muscle cells.
Feb 24, 2023 · Intercalated discs are part of the sarcolemma and contain two structures important in cardiac muscle contraction: gap junctions and desmosomes. A gap junction forms channels between adjacent cardiac muscle fibers that allow the depolarizing current produced by cations to flow from one cardiac muscle cell to the next.
