Absorption in the Small Intestine

• What is the primary function of the small intestine in digestion?

  To absorb the products of digestion into the bloodstream.
• What are the adaptations of the small intestine for absorption?

  • Long length (around 5 meters)
  • Presence of villi to increase surface area
  • Microvilli on villi for further surface area increase
  • Good blood supply to maintain concentration gradient
  • Thin membrane for short diffusion path
• What enzyme digests starch into simple sugars?

  Amylase.
• How do villi contribute to the absorption process in the small intestine?

  They increase surface area and have a good blood supply to enhance absorption.
• Why is a good blood supply important for the function of the small intestine?

  It maintains a concentration gradient for efficient absorption.
• What role do microvilli play in the small intestine?

  They increase the surface area for absorption even further.
• What is the significance of having a thin membrane in the small intestine?

  It provides a short diffusion path for rapid absorption.
• How are molecules that cannot be absorbed by diffusion taken up in the small intestine?

  They are absorbed by active transport.