What are cardiomyocytes?

Cardiomyocytes are specialized muscle cells that make up the myocardium, which is the muscular middle layer of the heart wall. These cells are responsible for the heart's ability to contract and pump blood throughout the body. Cardiomyocytes contain sarcomeres, which are the fundamental units of muscle contraction, and they exhibit unique characteristics such as intercalated discs that allow for coordinated contractions and efficient communication between cells. Their ability to generate electrical impulses and contract in a synchronized manner is essential for maintaining a regular heartbeat and overall cardiovascular health.

In contrast, the other options refer to different types of cells with distinct functions: connective tissue cells do not provide the contractile properties necessary for heart function; nerve cells are involved in transmitting signals that regulate heart rate but are not responsible for contraction; and endothelial cells are specialized cells that line blood vessels but do not contribute to the heart's muscular properties.