Organization and Regional Function of the Alimentary Canal

Organization and Regional Function of the Alimentary Canal
The metazoan alimentary canal can be divided into five major regions: (1) reception, (2) conduction and storage, (3) grinding and early digestion, (4) terminal digestion and absorption, and (5) water absorption and concentration of solids. Food progresses from one region to the next, allowing digestion to proceed in sequential stages (Figures 34-9 and 34-10).

Figure 34-9 Generalized digestive tracts of a vertebrate and an insect, showing the major functional regions of the metazoan digestive system