Final answer:
The liver, gallbladder, and pancreas play vital roles in digestion by secreting and storing substances like bile and pancreatic juice necessary for the chemical breakdown and absorption of nutrients.
Step-by-step explanation:
While food does not pass through the liver, gallbladder, and pancreas, these organs are essential for digestion. The liver is the largest internal organ and it has a dual role in digestion and detoxification, producing bile which is crucial for the emulsification and breakdown of fats in the duodenum. The gallbladder serves as a storage and concentration chamber for bile, releasing it when needed during digestion. Moreover, the pancreas secretes pancreatic juice, which includes a mixture of digestive enzymes and bicarbonate ions that help digest fats, carbohydrates, and proteins into smaller molecules, and it also neutralizes the acidic food coming from the stomach, creating a neutral environment necessary for the function of digestive enzymes in the duodenum.