Patient Care Technician (PCT) AAH Practice Exam

What do electrical impulses stimulate in the heart?

1. The valves of the heart

2. The chambers of the heart

3. The pericardium

4. The atrioventricular node

The correct answer is: The chambers of the heart

The heart's electrical impulses play a crucial role in coordinating its function, particularly in stimulating the chambers of the heart. The electrical impulses originate in the sinoatrial (SA) node, known as the heart's natural pacemaker, and cause the atria to contract. Following this, the impulses travel to the atrioventricular (AV) node and subsequently lead to the contraction of the ventricles. This sequence of events ensures that the heart pumps blood efficiently throughout the body. While the atrioventricular node is involved in the conduction of these impulses, it is not directly stimulated by the impulses themselves but instead ensures that the electrical signal is transmitted to the ventricles after a slight delay, allowing for proper timing between the contractions of the atria and ventricles. The valves of the heart and the pericardium, while important for heart function, are not primarily stimulated by electrical impulses; rather, they respond to the pressure differences created by the contraction of the chambers. Therefore, the choice that accurately reflects what electrical impulses stimulate in the heart is the chambers, as these structures are directly responsible for the rhythmic contractions necessary for effective blood circulation.