Final answer:
Intrinsic control of motility and secretion in the GI tract is afforded by the enteric nervous system, which contains two plexuses: the myenteric plexus and the submucosal plexus.
Step-by-step explanation:
Intrinsic control of motility and secretion in the GI tract is afforded by the enteric nervous system. This system contains approximately 100 million motor, sensory, and interneurons that are grouped into two plexuses: the myenteric plexus and the submucosal plexus. The myenteric plexus, located in the muscularis layer of the alimentary canal, is responsible for motility, while the submucosal plexus, located in the submucosal layer, regulates digestive secretions and reacts to the presence of food.