[Molecular mechanism of excitation and contraction in cardiac muscle].
The function of the heart is to pump blood in sufficient quantity to satisfy the metabolic requirements of tissues in the body at any given time. There are two ways by which the heart pumps different amounts of blood per unit time; one is the change in frequency of contraction, while the other is the amount of blood ejected during a single contraction (stroke volume). The former is related to the frequency of generation of action potential in the pacemaker cells, while the other is concerned with the change in myoplasmic Ca2+ concentration and the change in Ca(2+)-sensitivity of the contractile system. A number of regulatory mechanisms, with overlaps in their function, are involved in both cases.
Sugi
H
H
Department of Physiology, School of Medicine, Teikyo University.
D000200:Action Potentials; D000255:Adenosine Triphosphate / Q000378:metabolism; D002118:Calcium / Q000378:metabolism / Q000502:physiology; D002135:Calcium-Binding Proteins / Q000502:physiology; D002302:Cardiac Output; D006339:Heart Rate; D006801:Humans; D008875:Middle Aged; D009200:Myocardial Contraction; D009206:Myocardium / Q000378:metabolism; D010766:Phosphorylation; D012519:Sarcoplasmic Reticulum / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D014336:Troponin / Q000378:metabolism; D000099211:Phospholamban
D000255:Adenosine Triphosphate; D002118:Calcium; D002135:Calcium-Binding Proteins; D012964:Sodium; D014336:Troponin; D000099211:Phospholamban