Q1.
Look at Fig. 9.4. It is a sketch of a stretched-out alimentary canal. Guess how long it is.
Answer
Most students guess about a metre or two — the answer is far bigger. The small intestine alone is almost 6 metres long, which is nearly twice the height of your classroom. Add the other parts and the whole canal is longer still.
| Part of the alimentary canal | Approximate length | How to picture it |
|---|---|---|
| Small intestine | about 6 m | Twice the height of a classroom; the longest part of the canal |
| Large intestine | about 1.5 m | Shorter than the small intestine, but wider |
Why it happens: such a long tube is folded and coiled to fit inside the abdomen. Length is useful — the longer the food stays in contact with the digestive juices and the absorbing wall, the more completely it is digested and absorbed.
Try This: mark 6 metres on the ground with a measuring tape or a piece of rope and stand beside it. That single length of rope is the small intestine, coiled up inside you.