Animals respiratory system

Exchange surfaces
1. Specialised area, adapted so molecules pass easily
2. Large organisms
  1. Small SA:V
    1. Multicellular
      1. Large diffusion distance
        Need more supplies due to more activity
  2. Specialised exchange system
    1. Transport system
  3. Large SA
    1. Thin barrier
      1. Fresh supply/ Removal of molecules
        Conc gradient steep
3. Small organisms
  1. Large SA:V
    1. Don't require many nutrients, due to less activity
Lungs
1. Lots of alvleoli
  1. SA
  2. Partially permeable membrane
    1. Allow CO2 + O2 diffusion
    2. Thin barrier
      1. alveolus wall 1 cell thick
        Squamous cells 1 cell thick + flattened
        Capillaries close contact to alveolus
        RBC squeezed against capillary wall
        Total barrier is only 2 cell thick
      2. Diffusion gradient maintained
        High O2 supply, low O2 on demand side
Components
1. Cartilage
  1. Smooth muscle
    1. Elastic fibres
      1. Goblet cells
        Cilliated epithelium
        Tiny hair like projections
        Wafts mucus into stomach where enzymes destroy it
        Secrete mucus
        Traps tiny particles reducing infection
      2. Smooth muscle relaxes, elastic fibres recoil to original size
        Dilates airway
    2. Contracts which constricts airway - lumen gets smaller
      1. Allergies
  2. Structural role
    1. Supports trachea and bronchi
    2. Prevents collapse when air pressure is low inside
    3. Not complete ring, flexibility
Inhalation
1. Diagphragm contracts, pushes organs down
  1. External intercostal muscles contract and raise ribs
    1. Internal relax
      1. Chest cavity volume increases
        Air moves into lung
Exhalation
1. Diagphram relaxes, pushed up by displaced organs
  1. External intercostal muscles relax and ribs lower
    1. Internal contract
      1. Volume decreases

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Animals respiratory system

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	Erstellt von rachbreen vor etwa 11 Jahre