What is the primary function of the digestive system?

The primary function of the digestive system is to break down nutrients for absorption. This system is responsible for converting the food we eat into smaller, absorbable components, such as carbohydrates, proteins, fats, vitamins, and minerals. The process begins in the mouth, continues in the stomach, and is completed in the intestines where these nutrients are absorbed into the bloodstream and made available to the body for energy, growth, and repair. By efficiently breaking down food, the digestive system ensures that the body receives the essential nutrients it needs to operate effectively.

In contrast, the other choices relate to different functions of the body: supplying oxygen is primarily a function of the respiratory system; coordinating bodily responses involves the nervous system; and regulating hormone levels primarily falls under the endocrine system. These functions are crucial for overall health but do not pertain to the main role of the digestive system.