Function: spontaneous rhythmic contraction.
Composition: contractile proteins: actin, myosin, tropomyosin, troponin and others; myoglobin, glycogen, calcium ions...
Origin: visceral sheath of splanchnotom, mesoderm.
Function: cardiac contracting cells
Cardiac conducting cells, Purkinje cells, pacemaker cells
Function: generation and conduction of impulses.
Location: sinoatrial node (pacemaker), atrioventricular node, atrioventricular (His) bundle, Purkinje fibers
Function: contraction and secretion of Atrial Natriuretic Peptide.
Location: left and right cardiac atrium.