| Which differentiated cell type is used |
| Label |
cardiac muscle cell |
| Link |
http://purl.obolibrary.org/obo/CL_0000746 |
| Description |
Cardiac muscle cells are striated muscle cells that are responsible for heart contraction. In mammals, the contractile fiber resembles those of skeletal muscle but are only one third as large in diameter, are richer in sarcoplasm, and contain centrally located instead of peripheral nuclei.; This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies only to some subtypes and species, and so should not be considered definitional.
Cardiac muscle cells, also known as cardiomyocytes or cardiac myocytes, are specialized cells that form the heart tissue. These cells are elongated, branched, and contain a single centrally located nucleus. Their anatomy is composed primarily of densely packed myofibrils, which are protein structures that consist of sarcomeres - the fundamental units of muscle contraction. Cardiac muscle cells are united at their ends through specialized junctions known as intercalated discs, which allow the heart to contract in a unified, powerful and rhythmic way.
Functionally, cardiac muscle cells are responsible for the heart's consistent pumping action that circulates blood throughout the body. Unlike most cells in the body, cardiac muscle cells spontaneously depolarize and generate action potentials without external stimulation. This unique trait stems from the presence of ion channels in the cells' membrane that allow a cyclic flow of ions across the membrane, which create the electrical impulses necessary for heart contraction. The spread of these electrical signals from one cardiac muscle cell to another - facilitated by the interconnected network made by the intercalated disks - results in a synchronized contraction of the heart muscle.
Unlike skeletal muscle cells which can tire and need rest, cardiac muscle cells have to work ceaselessly throughout the entire lifespan, without the opportunity for rest, to ensure continuous circulation of blood. This is made possible through the high volume of mitochondria and a constant supply of oxygen from coronary circulation. In conclusion, cardiac muscle cells, through their unique structure and vital functionality, play a pivotal role in sustaining life by providing the means for blood to reach every cell in the body.; This class encompasses the muscle cells responsible for heart* contraction in both vertebrates and arthropods. The ultrastucture of a wide range of arthropod heart cells has been examined including spiders, horseshoe crabs, crustaceans (see Sherman, 1973 and refs therein) and insects (see Lehmacher et al (2012) and refs therein). According to these refs, the cells participating in heart contraction in all cases are transversely striated. Insects hearts additionally contain ostial cells, also transversely striated muscle cells, but which do not participate in heart contraction. |
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