Cardiac muscle is a specialized type of muscle found only in the heart. It is responsible for pumping blood throughout the body, ensuring that oxygen and nutrients reach all organs and tissues. Unlike other muscles, cardiac muscle works involuntarily, meaning we don't have to think about it for it to function. Its unique structure allows it to contract rhythmically and continuously without tiring. This muscle is made up of interconnected cells called cardiomyocytes, which help transmit electrical signals that trigger heartbeats. The sinoatrial node, often referred to as the heart's natural pacemaker, plays a crucial role in regulating the rhythm of cardiac muscle contractions.