cardiac muscle cell regular cardiac myocyte 2010-08-23T11:33:10Z regular cardiac muscle fiber FMA:67967 A cardiac myocyte that is connected to other cardiac myocytes by transverse intercalated discs (GO:0014704) at a regular interval. Cardiac myocytes, also known as cardiac muscle cells, form the majority of the cardiac tissue and are responsible for the contractile function of the heart. These myocytes are columnar-shaped cells with centrally located nuclei, and they exhibit visibly striated cytoplasm due to the organized array of myofibrils, which are composed of filaments of actin and myosin. Cardiac myocytes connect with each other through specialized structures called intercalated discs, facilitating electrical and mechanical continuity and enabling synchronous contraction of the heart. They also possess a high number of mitochondria to meet their high energy demand for continuous heartbeat action. Cardiac myocytes are capable of automaticity, meaning they have the unique ability to spontaneously and rhythmically generate their electrical impulses, a characteristic led by pacemaker cells. The electrical signals initiated and propagated in these cells are responsible for heartbeats. They also respond to the electrical signals transmitted by the autonomic nervous system and chemical signals like hormones. Thus, cardiac myocytes not only participate in maintaining the heart’s function but also play a role in modulating heart rate and strength of contraction in response to the body's changing needs. Consequently, malfunction of these cells leads to serious cardiac diseases such as heart failure and arrhythmias. (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.) regular cardiac muscle cell