Week 9 Learning progressions

• Define boyles law


  PV = K

  The volume of a gas and pressure are inversely proportional at a given temperature.

  ex. when pressure increases, the volume decreases. vice versa
• Respiration is gas exchange
• Internal respiration

  Gas exchange between systemic cells and capillaries

  • drop off O2 and pick up CO2
• External respiration 


  Gas exchange between atmospheric air and capillaries in lungs

  • drop off CO2 and pick up O2
  • Requires ventilation (mechanical process that allows air to come in/out)
  • inspiration = bringing air in
  • Expiration = expelling air
• Respiration DOES NOT equal ventilation
• Internal respiration DOES NOT equal cellular respiration
• Air in/out lungs


  Manipulating volume to change pressure by inhalation and exhalation

  • Volume inc, pressure dec
  • INVERSELY RELATED
• Inspiration

  • Skeletal muscles expand in rib cage
  • Increase volume in lungs
  • Decrease in pressure of lungs, lower than atmospheric pressure
  • Air enters lungs
• Expiration

  • Skeletal muscles relax closing rib cage
  • Volume in lungs decrease
  • Pressure in lungs increase to be higher than atmospheric pressure
  • air expelled from lungs
• We get air in/out of our lungs by changing the volume of our lungs.
• What affects air going in/out of lungs?

  • Skeletal muscles changing volume of rib cage (recruit more skeletal muscles, inc air).
  • Airway diameter
  • Compliance and elastance
  • Surfactant
• Airway diameter

  • Bronchoconstriction = parasympathetic nervous system
  • Prevents pathogens/pulltants from entering
  • Bronchodilation = sympathetic nervous system
• Alveoli 


  Sacs with thin membranes used as a structural/functional unit of external respiration
• Compliance 


  Alveoli are able to expand
• Elastance 


  Alveoli can go back to their original shape and size
• Surfactant


  Chemical secreted by alveoli to break up the adhesive and cohesive properties of H2O so that the alveoli doesn’t collapse.

  • Adhesive - attach to other things
  • Cohesive - H2O attaching to itself
• How can pollution affect respiratory health?

  • Food deserts/lack of fresh produce
  • Stress
  • Diet
  • Exercise