B2.9 Specialised exchange surfaces

• What are specialized exchange surfaces?

  Parts of an organism for substance exchange
• What is the main aim of the video?

  To explain common features of exchange surfaces
• 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
• What does it mean for exchange surfaces to be permeable?

  They allow substances to diffuse across
• 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
• Why do we need a good supply of air in alveoli?

  To maintain a high concentration of oxygen
• 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
• Who is the presenter of the video?

  Amadeus
• What does the learning platform offer?

  Videos, practice questions, and progress tracking
• Is the learning platform free?

  Yes, it is completely free
• Where can you find the link to the lesson?

  In the description down below
• How are the videos arranged for the subject?

  In a playlist
• What is an exchange surface?

  A part of an organism over which substances are exchanged with the environment 
• Where are alveoli found?

  Lungs
• The small protrusions of the lining of the small intestines are called villi. These have a large surface area which increases the area over which we can absorb nutrient molecules.
• Root hair cells absorb water and mineral ions from the soil.
• State and explain three features that most exchange surfaces have in common. 

  • Feature 1 - Large surface area

  >Lots of molecules can diffuse across at the same time

  • Feature 2 - Surfaces are very thin

  >Substances only have to diffuse a short distance

  • Feature 3 - Surfaces are permeable 

  > Substances are able to pass through the surface
• State and explain two features that animal exchange surfaces have in common. 

  • Feature 4 - Good blood supply (good supply of 'internal medium')

  > Maintains a strong concentration gradient as blood is constantly replaced

  • Feature 5 - Good supply of 'external medium'

  >Maintains a strong concentration gradient as the air or food etc is constantly replaced
• What is the first feature of alveoli that aids in gas exchange?

  Lots of alveoli provide a large surface area
• Why does having many alveoli benefit gas exchange?

  It allows many molecules to diffuse simultaneously
• What is the second feature of alveoli that enhances gas exchange?

  Surfaces are very thin, only 1 cell thick
• How does the thinness of alveoli surfaces aid in diffusion?

  It allows substances to diffuse a short distance
• What is the third feature of alveoli that facilitates gas exchange?

  Surfaces are permeable
• Why is permeability important for alveoli surfaces?

  It allows oxygen and carbon dioxide to diffuse
• What is the fourth feature of alveoli that supports gas exchange?

  Good blood supply
• How does a good blood supply benefit alveoli?

  It maintains a strong concentration gradient
• What is the fifth feature of alveoli that enhances gas exchange?

  Good supply of air
• Why is a good supply of air important for alveoli?

  It maintains a strong concentration gradient
• How does the replacement of air in the alveoli affect gas exchange?

  It ensures a constant supply of oxygen-rich air
• Which adaptation in plants contributes to the efficient exchange of gases?

  The flattened shape of their leaves