The Digestive System 1. Explain the three phases of gastric activity. 2. What is the role of the enterogastric reflex during the intestinal phase of gastric activity? 3. Some substances are absorbed by the small intestine easily through or transport 4. A/an is a nutrient that the body requires in large quantities, whereas a/an. is one that the body requires in much smaller quantities. 5. An nutrient must be supplied by the diet. 6. Glucose is stored by the process of 7. Distension of stretch receptors in the colon stimulates the.