What is an important function of the digestive system?

• A. Absorbing nutrients into the body
• B. Producing hormones that regulate mood
• C. Exchanging gases with the atmosphere
• D. Storing minerals for later use

Answer: (A)

Absorbing nutrients into the body is a central function of the digestive system. After food is broken down, nutrients such as glucose, amino acids, and fatty acids pass through the lining of the small intestine and enter the bloodstream, where they are carried to cells throughout the body. The small intestine’s villi and microvilli greatly increase surface area to make this absorption efficient, ensuring the body gets energy and the building blocks it needs for growth and repair.

Other options don’t fit as the main function: mood regulation is primarily a brain and endocrine process, not a digestive job; exchanging gases with the atmosphere is the domain of the respiratory system; and storage of minerals happens in bones and other tissues, not primarily in the digestive system.