cardiomyocyte
(noun)
A cardiac muscle cell (myocyte) in the heart.
(noun)
A cardiac muscle cell (or myocyte) in the heart, which makes up the cardiac muscle tissue.
Examples of cardiomyocyte in the following topics:
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Microscopic Anatomy
- Cardiac muscles are composed of tubular cardiomyocytes, or cardiac muscle cells.
- The cardiomyocytes are composed of tubular myofibrils, which are repeating sections of sarcomeres.
- Intercalated discs are gap junctions that link cardiomyocytes so that electrical impulses (action potentials) can travel between cells.
- In cardiac muscle, intercalated discs connecting cardiomyocytes to the syncytium, a multinucleated muscle cell, to support the rapid spread of action potentials and the synchronized contraction of the myocardium.
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Myocardial Thickness and Function
- The myocardium (cardiac muscle) is the thickest section of the heart wall and contains cardiomyocytes, the contractile cells of the heart.
- The myocardium, or cardiac muscle, is the thickest section of the heart wall and contains cardiomyocytes, the contractile cells of the heart.
- Cardiomyocytes are shorter than skeletal myocytes and have fewer nuclei.
- The myosin head also binds to ATP, the source of energy for cellular metabolism, and is required for the cardiomyocytes to sustain themselves and function normally.
- Cardiomyocytes have a large number of mitochondria, enabling continuous aerobic respiration.
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Layers of the Heart Walls
- It is composed of cardiac muscle cells, or cardiomyocytes.
- Cardiomyocytes are specialized muscle cells that contract like other muscle cells, but differ in shape.
- Due to their continuous rhythmic contraction, cardiomyocytes require a dedicated blood supply to deliver oxygen and nutrients and remove waste products such as carbon dioxide from the cardiac muscle tissue.
- The endocardium may regulate metabolic waste removal from heart tissues and act as a barrier between the blood and the heart muscle, thus controlling the composition of the extracellular fluid in which the cardiomyocytes bathe.
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Mechanism and Contraction Events of Cardiac Muscle Fibers
- Cardiomyocytes are capable of coordinated contraction, controlled through the gap junctions of intercalated discs.
- The mechanism for CIRC is receptors within the cardiomyocyte that bind to calcium ions when calcium ion channels open during depolarization, releasing more calcium ions into the cell.
- An action potential, induced by the pacemaker cells in the sinoatrial (SA) and atrioventricular (AV) nodes, is conducted to contractile cardiomyocytes through gap junctions.
- As the action potential travels between sarcomeres, it activates the calcium channels in the T-tubules, resulting in an influx of calcium ions into the cardiomyocyte.
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The Cardiac Cycle
- The pumping of the heart is a function of the cardiac muscle cells, or cardiomyocytes, that comprise the heart muscle.
- Cardiomyocytes are distinctive muscle cells that are striated like skeletal muscle, but pump rhythmically and involuntarily like smooth muscle; they are connected by intercalated disks exclusive to cardiac muscle .
- Cardiomyocytes are self-stimulated for a period of time; isolated cardiomyocytes will beat if given the correct balance of nutrients and electrolytes.
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Energy Requirements
- Cardiomyocytes contain large numbers of mitochondria, the powerhouse of the cell, enabling continuous aerobic respiration and ATP production required for mechanical muscle contraction.
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Electric Activity in the Heart
- These fibers consist of specialized cardiomyocytes that are able to conduct cardiac action potentials more quickly and efficiently than any other cells in the heart.