Here is a comprehensive summary of the article on cardiac physiology:

Cardiac physiology is the study of the heart's healthy function, focusing on how it acts as a powerful double pump to ensure continuous blood circulation throughout the body. This vital process involves two main circuits: the pulmonary circuit, which collects oxygen from the lungs and releases carbon dioxide, and the systemic circuit, which delivers oxygen and nutrients to the body's cells while gathering waste products. Blood flows in a single direction, moving from the atria to the ventricles and then into major arteries, a path regulated by four specialized heart valves that prevent backflow. Notably, the left ventricle has a thicker, stronger muscle wall, enabling it to generate the high pressure necessary to pump blood through the entire systemic circulation. A unique characteristic of the heart is its autorhythmicity, where specialized pacemaker cells initiate their own electrical impulses, causing the cardiomyocytes to contract in a coordinated manner to effectively pump blood.