The Digestive System

• What is meant by a tissue?

  A tissue is a group of cells with a similar structure and function.
• What is meant by an organ?

  An organ is a group of tissues working together for a specific function.
• What is meant by an organ system?

  An organ system is a group of organs that work together to form organisms.
• What are the main components of the digestive system?

  • Mouth
  • Esophagus
  • Stomach
  • Small intestine
  • Large intestine
  • Liver
  • Pancreas
• Why are muscle cells considered specialized?

  Because they contain special protein fibers for contraction and many mitochondria for energy.
• What is the role of enzymes in digestion?

  • Break down large food molecules into smaller molecules
  • Facilitate absorption into the bloodstream
• What are the three main nutrients found in food?

  Carbohydrates, proteins, and lipids (fats).
• Why must large food molecules be digested?

  Because they are too large to be absorbed into the bloodstream.
• What happens to food in the stomach?

  • Digestion of proteins begins
  • Contains hydrochloric acid to aid enzyme function
  • Churning action turns food into a fluid
• What is the function of bile in digestion?

  To speed up lipid digestion and neutralize stomach acid.
• How are small food molecules absorbed in the small intestine?

  • By diffusion
  • By active transport
• What happens to water in the large intestine?

  Water is absorbed into the bloodstream.
• What is the final product released from the body after digestion?

  Feces.
• What are the uses of the products of digestion in the body?

  • Build new carbohydrates
  • Build new lipids
  • Build new proteins
  • Some glucose is used in respiration