What is the primary function of the circulatory system?

The primary function of the circulatory system is to transport nutrients and oxygen to body cells. This system plays a critical role in maintaining homeostasis within the body. The heart pumps oxygenated blood from the lungs through the arteries to various tissues and organs where oxygen is delivered, and crucial nutrients are supplied. Alongside oxygen and nutrients, the circulatory system also facilitates the removal of carbon dioxide and metabolic waste products from the cells, helping to maintain a stable internal environment.

While the circulatory system does have secondary roles that relate to temperature regulation, hormone distribution, and immune function, these are not its primary functions. The regulation of body temperature is primarily handled by the integumentary system and involves blood flow adjustments. Hormonal production occurs in glands like the endocrine system, and while the circulatory system is involved in transporting hormones once they are produced, it does not produce them. Similarly, the immune system relies on the circulatory system to transport immune cells and antibodies, but its primary function focuses on nutrient and oxygen transport.