How are the activities of gastrointestinal tract regulated?

The activities of the gastrointestinal tract are under neural and hormonal control for proper
coordination of different parts
(i) The sight, smell and/or the presence of food in the oral cavity can stimulate the secretion of saliva.
(ii) Similarly, gastric and intestinal secretions are also stimulated by neural signals.
(iii) The muscular activities of different parts of the alimentary canal can also be moderated by neural mechanisms (both local and through CNS).
(iv) Hormonal control of the secretion of digestive juices is carried out by local hormones produced by the gastric and intestinal mucosa.