What is the primary function of the heart?

The primary function of the heart is to pump blood throughout the body. This action is vital for maintaining the circulation of oxygen-rich blood to the organs and tissues while facilitating the removal of carbon dioxide and other metabolic waste products. The heart operates as a muscular organ with four chambers, working in a coordinated manner to ensure efficient blood flow. This pumping mechanism is crucial for sustaining life, as it delivers essential nutrients and oxygen to the cells while simultaneously supporting the immune system and other bodily functions through blood circulation.

The other options describe important bodily functions that occur within different systems but are not the primary role of the heart. Regulating temperature involves mechanisms related to the hypothalamus and the vascular system; filtering toxins primarily occurs in the kidneys; and oxidizing nutrients is a biochemical process that largely takes place in the mitochondria of cells rather than being a function of the heart itself.