National League for Nursing (NLN) Science Practice Exam

Which of the following is not classified as an accessory organ?

1. Liver

2. Pancreas

3. Gallbladder

4. Stomach

The correct answer is: Stomach

The stomach is classified as a primary organ in the digestive system, responsible for the mechanical and chemical breakdown of food. It plays a crucial role in digestion, wherein food is mixed with gastric juices to form chyme, which then moves into the small intestine for further digestion and absorption. In contrast, the liver, pancreas, and gallbladder are considered accessory organs because they do not come into direct contact with the food as it passes through the digestive tract but are essential for aiding digestion. The liver produces bile, necessary for fat emulsification; the pancreas releases digestive enzymes and bicarbonate to aid in digesting carbohydrates, proteins, and fats; and the gallbladder stores and concentrates bile, releasing it into the small intestine when needed. Understanding the distinction between primary and accessory organs in digestion helps clarify their roles and functions in the overall process of digesting food, highlighting why the stomach is not classified as an accessory organ.