Which organs are part of the alimentary canal in the human digestive system?

Step 1: Analyze the question The question asks which option lists only organs that are part of the alimentary canal (the gut). This is the continuous tube through which food actually passes, from mouth to anus.

Step 2: The concept The digestive system has two groups of structures:

• Alimentary canal (food passes through): mouth (buccal cavity), pharynx, oesophagus, stomach, small intestine (duodenum, jejunum, ileum), large intestine (caecum, appendix, colon), rectum, anus.
• Accessory organs (food does NOT pass through; they produce or store secretions): salivary glands, liver, gallbladder, pancreas. The tongue is also usually treated as an accessory structure in the mouth.

Step 3: Check each option

• A. Salivary glands, tongue, pharynx: Salivary glands are accessory organs, and the tongue is an accessory structure. Only the pharynx is part of the canal. Not correct.
• B. Large intestine, appendix, rectum: The large intestine is part of the canal. The appendix is a projection off the caecum, which is part of the large intestine, so it is counted as part of the canal. The rectum is the final part of the canal. All three belong. Correct.
• C. Stomach, liver, gallbladder: The stomach is in the canal, but the liver and gallbladder are accessory organs. Not correct.
• D. Oesophagus, pancreas, small intestine: The oesophagus and small intestine are in the canal, but the pancreas is an accessory gland. Not correct.

Step 4: Answer Option B is the only one in which every organ is part of the alimentary canal.

Tip: To remember the accessory organs, think "S-L-G-P": Salivary glands, Liver, Gallbladder, Pancreas. Food never passes through them. If an option contains any of these, eliminate it right away. This trick removes A, C and D here.