Gulp: Adventures on the Alimentary Canal

The alimentary canal is the historical term for the human digestive tract. Early anatomists used this term for centuries to describe the pathway food takes through the body. Roach emphasizes this term because she believes it transforms the potentially disturbing reality of digestion into something elegant and peaceful, evoking images of a “tranquil, winding waterway” rather than biological processes (7). The term reflects how early scientists approached the human body like geographical explorers, naming anatomical parts after landscape features such as “the isthmus of the thyroid” and “the isles of the pancreas” (7). In the book’s Introduction, Roach uses the alimentary canal to present the digestive system as an adventure-filled journey.

Amylase is a digestive enzyme found in human saliva that breaks down starches into simple sugars that the body can absorb and use for energy. This enzyme is the primary digestive component in stimulated saliva, regardless of a person’s age. Roach explains that readers can actually taste amylase working when they chew bread, as a sweet flavor emerges from the interaction between saliva and starch. The presence of amylase in saliva demonstrates that digestion begins immediately in the mouth, before food even reaches the stomach.