What is the role of the circulatory system in the human body?

The circulatory system's primary role is to facilitate blood rotation throughout the body. This involves the transport of oxygen, nutrients, hormones, and waste products to and from cells. The heart acts as a pump to circulate blood through a network of vessels, ensuring that every part of the body receives the necessary substances to function effectively. This system also plays a key role in removing carbon dioxide and other waste products from the bloodstream, maintaining homeostasis and overall health.

The other options pertain to different physiological systems. Digestion is managed by the digestive system, which breaks down food and absorbs nutrients. Muscle movement is controlled by the muscular and nervous systems, where signals from the nervous system initiate muscle contractions. Regulation of body temperature is primarily the function of the integumentary system (skin) and the hypothalamus, which manages thermoregulation through processes like sweating and shivering. These systems complement the circulatory system but do not represent its primary function.