ISSA Nutritionist Practice Exam 2025 – Comprehensive All-In-One Guide to Exam Mastery!

The circulatory system is fundamentally responsible for the transportation of blood and nutrients throughout the body. This system consists of the heart, blood vessels, and blood itself. The heart pumps blood, which carries oxygen and essential nutrients to various tissues and organs, ensuring that they function optimally. Additionally, the circulatory system helps remove waste products from the metabolism of cells, including carbon dioxide, facilitating the overall balance and health of the body.

In contrast, the respiratory system focuses on gas exchange, including the intake of oxygen and the expulsion of carbon dioxide, but does not transport nutrients. The excretory system is primarily concerned with waste removal from the body, like urination, while the nervous system is responsible for transmitting signals and coordinating bodily functions rather than transporting blood or nutrients. Thus, the circulatory system is the correct choice as it plays a crucial role in providing sustenance and maintaining metabolic processes throughout the body.