Breathing

• Breathing


  Process our body needs oxygen for, carbon dioxide created as waste product
• Organ


  Group of tissues working together to perform a certain function
• Alveoli


  • Increase surface area of lungs for more gas exchange
  • Have thin walls, only 1 cell thick, for quick diffusion
• Inhalation


  1. Muscles between ribs contract, pulling ribcage up and out

  2. Diaphragm contracts, moving down

  3. Volume inside chest increases

  4. Pressure in chest decreases, drawing air into lungs
• Exhalation


  1. Muscles between ribs relax, pulling ribcage down and in

  2. Diaphragm relaxes, moving up

  3. Volume inside chest decreases

  4. Pressure in chest increases, pushing air out of lungs
• Bell-jar model


  • Rubber diaphragm represents diaphragm
  • Jar represents chest/rib cage
  • Balloons represent lungs
  • Tube represents trachea
• Benefits of bell-jar model: Rubber diaphragm is good representation, can clearly see pressure change drawing air in

  Problem: Ribcage (jar) doesn't move
• Water is pushed out of bottle because it is displaced by the air you are blowing in
• Volume of water pushed out equals amount of air your lungs can hold
• Exercise can increase lung capacity
• Smoking, old age or asthma can decrease lung capacity
• Factors affecting lung volume


  • Increase: Exercise
  • Decrease: Smoking, old age, asthma