specialised exchange surfaces

• What are specialized exchange surfaces?

  Parts of an organism for substance exchange
• What are the main specialized exchange surfaces in humans?

  Alveoli and Villi
• What is the function of alveoli?

  To exchange oxygen and carbon dioxide
• Where are alveoli located?

  At the ends of the bronchioles
• What do Villi do in the small intestine?

  Help absorb nutrients like glucose
• What specialized exchange surfaces do plants have?

  Root hair cells and leaves
• What is the role of root hair cells?

  To absorb water and mineral ions
• How do leaves function as exchange surfaces?

  They absorb carbon dioxide from the air
• What are the common features of specialized exchange surfaces?

  • Large surface area
  • Very thin surfaces
  • Permeable to exchanged substances
  • Good blood supply
  • Good supply of external medium
• Why is a large surface area important for exchange surfaces?

  It allows more molecules to diffuse simultaneously
• Why are exchange surfaces usually very thin?

  To shorten the diffusion distance
• How does a good blood supply benefit exchange surfaces?

  It maintains a concentration gradient
• What is the role of the external medium in exchange surfaces?

  It provides substances needed for exchange
• What are the five main features of specialized exchange surfaces?

  1. Large surface area
  2. Very thin surfaces
  3. Permeable to exchanged substances
  4. Good blood supply
  5. Good supply of external medium
• Why do we need to breathe in and out constantly for alveoli?

  To maintain a high concentration of oxygen
• How does a concentration gradient facilitate diffusion?

  It allows substances to move from high to low concentration