CVS Practice Test 2025 – Complete Exam Preparation

The process of myocyte contraction begins with the spread of an action potential, which allows for communication between adjacent cells. This electrical signal travels along the plasma membrane of the myocytes and is crucial for initiating contraction. When the action potential reaches the cell membrane, it opens ion channels, leading to depolarization and allowing ions, such as calcium, to enter the cell.

The choice that indicates the current spreading through gap junctions is a fundamental aspect of cardiac and smooth muscle contraction. Gap junctions enable the rapid transmission of electrical signals between adjacent myocytes, ensuring that the entire muscle tissue contracts in a coordinated manner. This is essential for effective heart function, as it allows for synchronous contraction necessary for pumping blood.

Understanding this initial step highlights the importance of cell communication in muscle physiology, setting the stage for the subsequent events, such as calcium binding to troponin and the interaction between actin and myosin.