A flagellum is a lash-like appendage that protrudes from the cell body of certain bacterial and eukaryotic cells. The primary role of the flagellum is locomotion, but it also often has function as a sensory organelle, being sensitive to chemicals and temperatures outside the cell. The similar structure in the archaea functions in the same way but is structurally different and has been termed the archaellum. Flagella are organelles defined by function rather than structure. Flagella vary greatly.
The digestive tract includes the esophagus (or food tube), stomach, small intestine/bowel, and colon or large intestine/bowel. It begins at the mouth and ends at the anus. Gut motility is the term given to the stretching and contractions of the muscles in the gastrointestinal (GI) tract.