Understanding the concepts presented in this chapter will enable the student to: 1. Describe the function of the following cellular components of cardiac myocytes: sarcolemma, intercalated disks, transverse (T)-tubules, myofibrils, myofilaments, sarcomeres, sarcoplasmic reticulum, and terminal cisternae. 2. Describe the composition of thick and thin myofilaments in cardiac myocytes. 3. Describe the significance of a functional syncytium within the heart. 4. Describe the steps of excitation–contraction coupling, including the role of T tubules, Ltype calcium channels, trigger calcium, terminal cisternae, ryanodine receptors (calciumrelease channels), troponin-C (TN-C), troponin-I (TN-I), troponin-T (TN-T), actin, myosin heads, adenosine triphosphate (ATP) hydrolysis, and sarco-endoplasmic reticulum calcium adenosine triphosphatase (SERCA) pump
