The Respiratory System (chp.6)

• Breathing


  Physical process that brings O2 into our body & releases CO2 & H2O from our body
• Breathing

  • Inhalation; air in
  • Exhalation; air out
• What are the main components of the breathing system and their functions?

  • Trachea: Brings air in and out
  • Bronchi: Brings air to lungs
  • Bronchioles: Carries air throughout lungs
  • Alveoli: Site of gaseous exchange
  • Diaphragm: Increases lung volume
  • Intercostal muscles: Moves ribs to increase lung volume
• Structure of system

  • Trachea- brings air in and out of the lungs rings of the cartilage, prevents lung collapse, makes sound
  • Bronchi- each bronchus brings air to a lung also has rings and cartilage
  • Bronchioles- divide repeatedly to carry air throughout the lungs to the alveoli
• Structure of breathing system

  • Alveoli- small air sacks surrounded by capillaries, gaseous exchange occurs here
  • Diaphragm- sheet of muscle that contracts to flatten, increasing volume of lungs and this brings air into them
  • Intercostal muscle- between each rib, contracts & moves the ribs up and out. Increasing volume of the lung and bringing air into the lungs.
• Gaseous exchange


  Occurs in alveoli of the lungs, O2 diffuses into the blood stream and CO2 differences out
• Smoking

  • Irritates the lungs cells, causing them to produce excess mucus - less volume
  • Tar from smoke coats cells
  • Lung cells are more likely to catch disease e.g cold
  • Lung cells are more likely to mutate leading to cancer
• Smoking + the heart

  • CO in the smoke goes into the blood
  • Excess mucus decreases lung volume
  • Tar decreases gaseous exchange

  These 3 combine to prevent enough O2 reaching cells of the body, the heart has to beat faster and harder to provide the O2 & this heads to heart strain.