The gastrointestinal (GD system is regulated in an integrated manner from two control systems.

One level of control is applied by the central nervous and endo­crine systems and is exerted in a manner similar to that for other organ systems. The second level of control is unique to the GI system and is exerted by intrinsic nervous and endo­crine components located within Gl organs. This intrinsic level of control allows the gut to regulate its functions auton­omously based on local conditions, such as the amount and type of food contained in the lumen. Coordination of GI function with the rest of the body is achieved by integration of intrinsic (within the gut) and extrinsic (outside of the gut) influences (Figure 27-1).