ABSTRACT
The human gut has evolved over many thousands of years to provide an efficient system for the extraction of nutrients from a varied diet. Functionally, the gut is divided into a preparative and primary storage region (mouth and stomach), a secretory and absorptive region (the midgut), a water reclamation system (ascending colon), and finally a waste-product storage system (the descending and sigmoid colon regions and the rectum). The organization of the upper gut facilitates the controlled presentation of calories to the systemic circulation
allowing the replete person to perform physical work, undergo social activities, and to go to sleep.
