What are the four functions of the digestive system?

Motility: Mechanical breakdown and mixing of ingested nutrients by smooth muscle movements, passage of nutrients through the digestive tract, and elimination of undigested or unabsorbed residues from the body.Secretion: Release of enzymes, hormones, and other substances that take part in digestion.Digestion: Chemical reduction of ingested nutrients into particles, then into molecules small enough to cross the lining of the gut and reach the internal environment of the body.Absorption: Passage of digested nutrients from the gut lumen into the blood or lymph, which distributes them throughout the body.