AEMCA Practice Exam

What are the two different types of cells that make up the heart?

1. Auto-rhythmic cells and contractile cells

2. Nodal cells and pacemaker cells

3. Cardiomyocytes and fibroblasts

4. Epithelial cells and smooth muscle cells

The correct answer is: Auto-rhythmic cells and contractile cells

The answer identifies the two primary types of cells that constitute the heart, namely auto-rhythmic cells and contractile cells. Auto-rhythmic cells are responsible for generating electrical impulses that initiate and regulate the heartbeat, effectively controlling the heart's rhythm. These cells are primarily found in specific areas of the heart such as the sinoatrial (SA) node and the atrioventricular (AV) node. They have the unique capability to depolarize spontaneously and create action potentials without requiring external stimuli. On the other hand, contractile cells, also known as cardiomyocytes, are the muscle cells of the heart that execute the contraction needed to pump blood. When stimulated by the electrical signals from the auto-rhythmic cells, these contractile cells shorten and generate force, leading to the heart's pumping action. This coordinated contraction is essential for effective blood circulation throughout the body. The other options present cell types that do not accurately categorize the primary cell types of heart function. Nodal and pacemaker cells are less precise in their descriptions of heart cells as a whole, while cardiomyocytes and fibroblasts would mix contractile cell types with connective tissue cells, which do not fulfill the heart's primary functions of contraction and rhythm