What is the primary function of the circulatory system?

The primary function of the circulatory system is to transport essential substances throughout the body, including oxygen, waste products, nutrients, hormones, and heat. This system ensures that cells receive the oxygen they need for cellular respiration while simultaneously transporting carbon dioxide and other metabolic wastes away from those cells to be expelled from the body. Additionally, it plays a critical role in distributing nutrients absorbed from digestion to various tissues and organs, as well as hormones produced by the endocrine system. By maintaining this steady flow, the circulatory system helps regulate body temperature and contributes to homeostasis, including the distribution of heat generated by metabolic processes.

This comprehensive movement of materials is vital for the overall function and health of an organism, making the circulatory system one of the key systems in maintaining life.