Multiple choice Which of these structures is a primary digestive system organ? Transverse Colon Pancreas Gall Bladder Salivary Glands Reveal answer Fill a bubble to check yourself A Correct answer Explanation The alimentary canal (primary organs) includes the mouth, pharynx, esophagus, stomach, small intestine, and large intestine (including the colon). The pancreas, gallbladder, and salivary glands are accessory organs.