FUNCTIONS OF THE DIGESTIVE SYSTEM

• Ingestion - the intake of food into the stomach
• Mastication - chewing
• Propulsion - movement of food in the digestive tract; takes 24-36 hours
• Mixing - moving of food back and forth within the digestive tract to mix with digestive secretions and help break it into smaller pieces
• Segmental contractions - mixing contractions that occur in the small intestine
• Secretion - aids the food to move through the digestive tract
• Mucus - lubricates the food and lining of the tract
• Digestion - breakdown of large organic molecules into their component parts

  • Carbohydrates > Monosaccharides
  • Proteins > Amino Acids
  • Triglycerides > Fatty Acids & Glycerol
• 2 types of digestion:

  • Mechanical digestion - mastication and mixing
  • Chemical digestion - accomplished by digestive enzymes
• Absorption - movement of molecules out of the digestive tract into the blood or lymphatic system
• Elimination - removal of waste products by digestion (primarily occurs in large intestine)
• Defecation - the process in which semisolid waste products called feces is eliminated