Advanced Patient Assessment Practice Exam

What term describes the sudden loss of the negative charge inside the myocardial cells?

1. Depolarization

2. Conductivity

3. Repolarization

4. Automaticity

The correct answer is: Depolarization

The term that describes the sudden loss of the negative charge inside the myocardial cells is depolarization. During depolarization, there is a rapid influx of sodium ions into the cells, which causes the membrane potential to become less negative or even positively charged. This change is crucial for the propagation of electrical impulses in the heart, leading to muscle contraction. In the context of cardiac function, depolarization is the first step in the action potential cycle. It initiates the contractile process of the myocardium, allowing the heart to pump blood effectively. The sequence is vital for the coordinated contraction of the heart chambers, which is essential for proper cardiovascular function. The other terms mentioned have distinct definitions that do not refer to the process of losing the negative charge. Conductivity refers to the ability of cardiac tissue to conduct electrical impulses, which, while related to the concept of depolarization, does not describe the actual loss of that negative charge. Repolarization is the process that follows depolarization, where the cells return to their resting negative state after the contraction. Automaticity is a characteristic of certain cardiac cells that allows them to generate electrical impulses without external stimuli, but it doesn’t refer to the event of charge loss itself.