What is the main purpose of the circulatory system?

The primary function of the circulatory system is to deliver oxygen and nutrients to the body tissues while simultaneously removing waste products like carbon dioxide and metabolic byproducts. This dual role is essential for maintaining the health and functionality of cells, which require a constant supply of oxygen and nutrients to perform their metabolic processes. The circulatory system achieves this through a network of blood vessels and the action of the heart, ensuring that every part of the body receives what it needs to thrive.

While regulating body temperature, supporting digestion, and providing sensation are important roles of other systems in the body, they are not the main purpose of the circulatory system. The circulatory system's critical role in supporting cellular metabolism and overall bodily functions underscores why the delivery of oxygen and nutrients, along with waste removal, is its foremost responsibility.