Chapter 5: Gas Exchange

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Created by
Aarush Sanghavi

Cards (10)

  • The Gaseous Exchange System
    The Diagram
  • Ventilation 

    Differences in air pressure caused by breathing
    Intercostal muscles (external and internal) and diaphragm
  • Inhalation (Breathing in)

    External intercostal muscles contract
    Internal intercostal muscles relax
    Raise ribs upwards and outwards
    The diaphragm contracts and flattens
  • Pressure when inhaling
    The volume inside thorax increases → pressure inside thorax decreases
    Atmospheric pressure > pressure inside thorax
    Air moves into the lungs
    Lungs inflate
  • Exhalation (Breathing out)
    External intercostal muscles relax
    Internal intercostal muscle contract
    Lower ribs downwards and inwards
    Muscle in the diaphragm relaxes
    The diaphragm bulges up due to pressure from organs below
  • Pressure when exhaling
    The volume inside thorax decreases → pressure inside thorax increases
    The pressure inside thorax > atmospheric pressure
    Air forced out of lungs
  • Gas Exchange in Unicellular Oxygen
    Rely on Diffusion alone
  • Diffusion definition
    Net movement of molecules or ions, from a place with a higher concentration to a place with a lower concentration down a concentration gradient as a result of random movement
  • Gas Exchange in larger organisms
    Require a Gas exchange system
    Gas exchange takes place in alveoli
  • How does Gas Exchange happen
    When air is inhaled close inhalationThe action of breathing in., oxygen diffuses from the alveoli into the blood to be used for respiration by the body's cells.