Gas Exchange

• what are adaptations of the alveoli?


  • large SA
  • thin walls for diffusion
  • good blood supply
  • good air ventilation
• where are goblet cells found?


  trachea and bronchi
• what do goblet cells do?


  secrete mucus to trap pathogens
• what does cilia do?


  the mucus trapped by goblet cells is moved up and into the throat by cilia
• what is the function of cartilage?


  • keep the airways open
  • prevent collapse of trachea
  • protects the trachea
• what is the oxygen percentage in inspired air?


  21%
• what is the nitrogen percentage in inspired and expired air?


  78%
• what is the CO2 percentage in inspired air?


  0.04%
• what is the CO2 percentage in expired air?


  4%
• during inspiration..


  diaphragm : contracts

  external intercoastal : contracts

  ribcage : moves upwards and outwards

  thorax : increases

  air pressure : decreases

  I DERTA coco muo id
• during expiration 


  diaphragm : relax

  external intercoastal muscle : relax

  ribcage : downwards and inwards

  thorax cavity : decreases

  air pressure : increases
• why does expired air contain less oxygen?


  oxygen is used up by cells in the body
• why does expired air contain more CO2?


  because CO2 is a waste product of respiration
• what is energy in a living organism used for?

  • protein synthesis
  • cell division
  • active transport
  • muscle contraction
• what are the effects of physical activity on the pH of blood?


  • pH decreases as CO2 is acidic
  • rate of aerobic respiration increases
  • more CO2 enters the blood