Which Layer of the Heart Has Actin,myosin,and Intercalated Discs

Question

Which layer of the heart has actin,myosin,and intercalated discs?
A) Myocardium
B) Endocardium
C) Epicardium
D) Pericardium

Accepted Answer

Actin and myosin are both contractile proteins that are found in the myocardium, which is the middle layer of the heart. Intercalated discs are specialized cell junctions that connect cardiac muscle cells and allow for synchronized contractions. Therefore, the correct answer is the myocardium (choice A). The other choices are not correct: the endocardium (choice B) is the inner layer of the heart that lines the chambers and heart valves, the epicardium (choice C) is the outer layer of the heart that covers the surface of the heart, and the pericardium (choice D) is the protective sac that surrounds the heart.