The lungs

• What is the primary function of the lungs?

  Gas exchange
• Why do humans need oxygen from the air?

  For respiration in body cells
• What happens to carbon dioxide in the blood?

  It needs to be expelled from the body
• How does air move in and out of the lungs?

  By the action of breathing
• Where are the lungs located in the body?

  In the thorax
• What separates the thorax from the abdomen?

  The diaphragm muscle
• What protects the lungs?

  The ribcage
• What is the function of the trachea?

  To carry air to the lungs
• What do the bronchi split into?

  Bronchioles
• Where does gas exchange occur in the lungs?

  In the alveoli
• How does gas exchange occur in the alveoli?

  By diffusion
• What does the blood contain when it returns to the lungs?

  Lots of carbon dioxide
• What happens to oxygen in the alveoli?

  It diffuses into the blood
• What happens to carbon dioxide in the alveoli?

  It diffuses out to be breathed out
• What occurs when blood reaches body cells?

  Oxygen is released and carbon dioxide is absorbed
• How does oxygen move from blood to body cells?

  By diffusion from high to low concentration
• What are the main structures involved in gas exchange in the lungs?

  • Trachea
  • Bronchi
  • Bronchioles
  • Alveoli
  • Blood capillaries