Which system controls the steady circulation of blood through the body?

The circulatory system is responsible for the steady circulation of blood throughout the body. It comprises the heart, blood vessels, and blood, playing a crucial role in transporting oxygen, nutrients, and hormones to cells while removing waste products like carbon dioxide. This system ensures that all body tissues receive adequate blood supply to function properly.

While the respiratory system is essential for gas exchange, providing oxygen to the blood and removing carbon dioxide, it does not control the circulation of blood itself. The digestive system is involved in the breakdown of food and nutrient absorption, but it is not directly responsible for blood circulation. The nervous system influences heart rate and blood vessel constriction but mainly serves as a control and communication network for the entire body rather than being the primary system governing blood circulation. Therefore, the circulatory system is the correct choice, as it directly manages the flow of blood needed for various bodily functions.