What is the primary function of the digestive system?

• A. To absorb nutrients from food
• B. To break down food into nutrients
• C. To regulate metabolic processes
• D. To filter toxins from the bloodstream

Answer: (B)

The primary function of the digestive system is to break down food into nutrients. This process begins in the mouth and continues through the esophagus, stomach, and intestines, where food is mechanically and chemically broken down into smaller, absorbable components.

From the moment food is ingested, digestive enzymes and acids act on it to transform complex molecules into simpler ones. This breakdown is crucial because nutrients such as carbohydrates, proteins, and fats need to be reduced to their building blocks—simple sugars, amino acids, and fatty acids—before they can be absorbed into the bloodstream.

Although absorbing nutrients from food is a key aspect of the digestive system's role, it is a subsequent step that follows the breakdown of food. The regulation of metabolic processes and filtering toxins are functions performed by other systems in the body, such as the endocrine system and the liver, respectively. Therefore, while the digestive system is important for nutrient absorption, its primary role centers on the breakdown of food, making the correct choice focused on that fundamental process.