cardiac muscle

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Related to Myoblasts, cardiac: Myofiber, Cardiac myocytes

car·di·ac mus·cle

the involuntary muscle comprising the myocardium and walls of the pulmonary veins and superior vena cava, consisting of anastomosing transversely striated muscle fibers formed of cells united at intercalated discs; the one or two nuclei of each cell are centrally located and the longitudinally arranged myofibrils have considerable sarcoplasm around them; connective tissue is limited to reticular and fine collagenous fibers; contraction is rhythmic and intrinsically stimulated.
Synonym(s): muscle of heart

cardiac muscle

n.
The specialized striated muscle tissue of the heart; the myocardium.

car·di·ac mus·cle

(kahr'dē-ak mŭs'ĕl)
The muscle forming the myocardium, consisting of anastomosing transversely striated muscle fibers formed of cells united at intercalated discs.
Synonym(s): muscle of heart.
Cardiac muscleclick for a larger image
Fig. 91 Cardiac muscle . The intercalated discs enable the rapid transmission of excitatory waves across the tissue.

cardiac muscle

a type of vertebrate muscle found only in the HEART, which appears to be halfway between INVOLUNTARY MUSCLE and STRIATED MUSCLE in that its fibres are striated, but contain a single nucleus (see Fig. 91 ). The action of cardiac fibres is to produce strong and rhythmic contractions from within, even when removed from the body (see MYOGENIC CONTRACTION). Unlike striated muscle, cardiac muscle does not become fatigued even though it is repeatedly stimulated. The heartbeat is controlled by the AUTONOMIC NERVOUS SYSTEM.