Intercellular Digestion:
1. Digestion occurs in the food vacuoles within cells.
2. Lysosomal enzymes are secreted into the food vacuole.
3. Products of digestion diffuse into the cytoplasm through the vacuolar membrane.
4. Ingestion occurs through pinocytic vesicle,e.g. protozoans, sponges and coelenterates.
Extracellular Digestion:
1. Digestion occurs outside of cells in the lumen of the alimentary canal.
2. Salivary, gastric pancreatic and intestinal enzymes are secreted into the digestive cavity.
3. Digested food materials are absorbed into the blood through gut epithelia.
4. Ingestion occurs through the mouth, e.g. coelenterates to chordates.