What is the primary role of the digestive tract?

The primary role of the digestive tract is to extract and absorb nutrients from the food we consume. The digestive process begins in the mouth, where food is mechanically broken down and mixed with saliva, and continues through the esophagus, stomach, and intestines. In the stomach, food is further digested with the help of digestive juices, breaking it down into smaller molecules.

As food moves into the small intestine, the majority of nutrient absorption occurs. The walls of the small intestine are lined with tiny villi and microvilli that increase the surface area, allowing for efficient absorption of nutrients such as proteins, fats, carbohydrates, vitamins, and minerals into the bloodstream. Once absorbed, these nutrients are transported to cells throughout the body to provide energy, support growth, and maintain bodily functions.

The other options focus on roles that are not the primary function of the digestive tract. Creating hormones typically involves other organs such as the pancreas and endocrine glands. Filtering blood is primarily the function of the kidneys, while regulating body temperature is managed by the body's thermoregulatory systems, including the skin and sweating mechanisms. Thus, extracting and absorbing nutrients remains the main function of the digestive tract.