Which system is responsible for transporting substances such as oxygen and nutrients in the body?

The circulatory system is essential for transporting substances throughout the body, including oxygen, nutrients, hormones, and waste products. This system consists of the heart, blood vessels, and blood. The heart pumps oxygen-rich blood from the lungs, where gas exchange occurs, to various tissues and organs. As blood circulates, it delivers vital nutrients and oxygen needed for cellular metabolism and also collects carbon dioxide and other waste products to be expelled from the body.

The digestive system, while crucial for breaking down food and absorbing nutrients, does not directly transport these substances. Instead, it prepares them for absorption into the bloodstream. The respiratory system is primarily involved in the exchange of gases, such as oxygen and carbon dioxide, in the lungs but does not carry these substances throughout the body. The endocrine system regulates various functions in the body through hormones but does not play a direct role in the transportation of oxygen and nutrients. Thus, the circulatory system is specifically designed for this critical role in maintaining homeostasis and supporting overall bodily functions.