The digestive system functions to absorb which of the following?

• A. All of the above
• B. Carbohydrates
• C. Fats
• D. Proteins

Answer: (A)

The digestive system absorbs all three major macronutrients: carbohydrates, fats, and proteins. Absorption happens mainly in the small intestine, where nutrients move from the gut into the bloodstream or lymphatic system. Carbohydrates are broken down to simple sugars and absorbed into the blood; proteins are digested to amino acids and absorbed into the blood; fats are emulsified and digested into fatty acids and monoglycerides, absorbed by enterocytes, reassembled into triglycerides, and packaged into chylomicrons that travel via the lymphatic system. The large intestine mainly reabsorbs water and electrolytes, not macronutrients. Because the system absorbs carbohydrates, fats, and proteins, all of the above is the best answer.