Which of the following is a digestive system organ?

• A. Stomach
• B. Teeth
• C. Liver
• D. Heart

Answer: (A)

Digestive system organs are parts of the body that directly participate in breaking down food and preparing nutrients for absorption. The stomach is a central hollow organ where both chemical and mechanical digestion occur: it secretes gastric juice, including acid and enzymes, to chemically break down proteins, and its muscular walls churn the contents to mix food into a semi-liquid chyme. This combination of secretion and churning happens right in the digestive tract, making the stomach a primary digestive organ. Teeth help with breaking food apart but are not an organ of the digestive tract itself; they’re structures in the mouth used for mastication. The liver assists digestion by producing bile but is often considered an accessory organ, while the heart belongs to the circulatory system and does not digest food.