What is the primary responsibility of the digestive system?

The primary responsibility of the digestive system is the absorption of nutrients. Once food has been mechanically broken down through processes such as chewing and mixing with digestive juices, the smaller molecules of nutrients can be absorbed into the bloodstream. This vital function takes place mainly in the small intestine, where numerous villi increase the surface area for maximum absorption. Nutrients such as carbohydrates, proteins, fats, vitamins, and minerals are transported to cells throughout the body to provide energy and support overall health.

Other functions, such as the secretion of hormones and mechanical digestion, are supportive roles that facilitate the overall process of digestion. The storage of waste, while an important aspect of the system, is more about the excretion process than the primary function of nutrient absorption. Therefore, the correct answer highlights the crucial role the digestive system plays in providing the body with the essential substances it needs to function effectively.