Lungs & Gas Exchange

• What is the primary function of the lungs in the human body?

  Gas exchange
• What is the name of the tube through which air passes into the lungs?

  Trachea
• What is the function of the cartilage in the trachea?


  It prevents the trachea from collapsing when we inhale
• What are the two smaller tubes that the trachea splits into?

  Bronchi
• What are bronchioles?


  They are smaller tubes that the bronchi subdivide into
• What are the tiny air sacs at the end of bronchioles called?

  Alveoli
• What is the role of alveoli in the lungs?


  They are the sites of gas exchange
• How does oxygen and carbon dioxide move in the alveoli?


  Oxygen diffuses into the bloodstream, and carbon dioxide diffuses out
• What are the adaptations of alveoli for gas exchange?


  • Millions of alveoli provide a huge surface area
  • Very thin walls create a short diffusion path
  • Good blood supply ensures rapid removal of oxygen
• Why is a good blood supply important for alveoli?


  It ensures that oxygen is rapidly removed, maintaining a steep concentration gradient
• How does breathing affect the rate of diffusion in the lungs?

  Breathing brings fresh oxygen into the alveoli and removes carbon dioxide
• What is the effect of high concentration gradients on gas exchange?


  They increase the rate of diffusion