Mammalian Lungs

• What is the primary function of all organisms in relation to their environment?

  All organisms exchange gases with their environment.
• What are the key features that enable rapid gas exchange in human lungs?

  • Many alveoli provide a large surface area.
  • Alveoli and capillary walls are one cell thick for short diffusion distance.
  • High concentration gradient maintained by circulation and ventilation.
  • Extensive capillary network around alveoli for large surface area.
• What is the trachea's role in the respiratory system?

  The trachea allows air to travel to the lungs.
• What is the function of the mucus layer in the trachea?

  The mucus traps dust and pathogens preventing them from entering the lungs.
• What are cilia and where are they found?

  Cilia are tiny hairs found on the lining of the airways.
• What is the function of cilia in the airways?

  Cilia waft mucus towards the top of the trachea to remove trapped particles and pathogens.
• How does cystic fibrosis affect mucus in the airways?

  Cystic fibrosis makes mucus sticky, increasing the chance of lung infections.
• What are three properties of gas exchange surfaces?

  Large surface area, thin walls, and a good blood supply.
• How is a large surface area ensured in the lungs?

  By having many alveoli.
• How is the concentration gradient maintained in the lungs?

  By circulation and ventilation.
• What is the role of the alveoli in the lungs?

  The alveoli facilitate gas exchange between air and blood.
• What is the difference between circulation and ventilation?

  Circulation refers to blood flow, while ventilation refers to air movement in and out of the lungs.
• What is the difference between endothelial and epithelial cells?

  Endothelial cells line blood vessels, while epithelial cells cover body surfaces.
• What is diffusion?

  Diffusion is the movement of molecules from an area of high concentration to an area of low concentration.
• Why do alveoli have a short diffusion distance?

  Because the walls of alveoli and capillaries are one cell thick.
• By which process are gases exchanged in the lungs?

  By diffusion.
• How are the lungs adapted for rapid gaseous exchange?

  They have a large surface area, thin walls, and a rich blood supply.
• What is a pathogen?

  A pathogen is a microorganism that can cause disease.
• What is the role of the trachea?

  The trachea allows air to travel to the lungs and traps dust and pathogens.
• How are the alveoli connected to the trachea?

  The alveoli are connected to the trachea through the bronchi and bronchioles.
• What are the benefits of mucus in our airways?

  Mucus traps dust and pathogens, preventing them from entering the lungs.
• What are cilia?

  Cilia are tiny hairs that help move mucus in the airways.
• What is the function of cilia in the respiratory system?

  Cilia help to waft mucus towards the top of the trachea.
• What is a symptom of cystic fibrosis?

  Increased chance of lung infections.
• Why does swallowing mucus reduce the risk of infection?

  Swallowing mucus helps to clear pathogens from the airways.
• What is osmosis?

  Osmosis is the movement of water across a semipermeable membrane.
• What is the structure of water?

  Water is composed of two hydrogen atoms and one oxygen atom (H2O).
• What are the properties of water?

  Water is a solvent, has a high specific heat, and is cohesive and adhesive.
• How can having cystic fibrosis increase the chance of lung infections?

  Sticky mucus in cystic fibrosis traps pathogens, leading to infections.
• How would you correct the statement: "the cell wall of the alveoli is very thin which is why the rate of gas exchange is faster"?

  The alveoli do not have cell walls; they have thin membranes for gas exchange.
• What is Fick's law?

  Fick's law states that the rate of diffusion is proportional to the surface area and concentration gradient.
• Using Fick's law, how are the lungs adapted for gas exchange?

  The lungs have a large surface area and maintain a high concentration gradient for efficient gas exchange.
• What are two properties visible in mammalian lung tissue that make it an efficient gas exchange surface?

  • Large surface area due to many alveoli.
  • Thin walls of alveoli and capillaries for short diffusion distance.
• How do the properties of mammalian lung tissue contribute to gas exchange efficiency?

  • Large surface area allows more gas to be exchanged.
  • Thin walls reduce the distance for diffusion, speeding up the process.