Respiratory system

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(No Transcript)
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• The tiniest bronchioles branch to the alveoli
  (sing. alveolus) which are tiny, multi-lobed
  air sacs made of simple squamous cells.

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A look at what we have seen so far

• http//www.mhhe.com/biosci/genbio/animation_quizze
  s/graphics/abm3s8a.ram

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And these put together allow us to breath.

• The process of breathing ventilation
• In order to understand the process it is
  important to look at the physics involved.
• http//www.mhhe.com/biosci/genbio/animation_quizze
  s/graphics/abm3s3h.ram
• Us.. McGraw-Hill Online Learning Center
  TestltBLURTgt

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• Tutorial 48.2 Airflow in Mammals ( good review )

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The site of gas exchange is the alveoli

• The process of respiration
• McGraw-Hill Online Learning Center TestltBLURTgt
• Shape of alveoli increase surface area

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• Having this thin wall enables air exchange with
  the equally-thin-walled capillaries of the
  circulatory system.
• Animation Quizzes

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Exchange of gases

• External respiration
• exchange of O2 CO2 between external environment
  the cells of the body
• efficient because alveoli and capillaries have
  very thin walls are very abundant (your lungs
  have about 300 million alveoli with a total
  surface area of about 75 square meters)
• Internal respiration - intracellular use of O2 to
  make ATP - occurs by simple diffusion along
  partial pressure gradients

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Partial pressure

• In summary, gases move from a region of higher
  partial pressure to a region of lower partial
  pressure.
• Animations partial pressure. Keep in mind above
  summary.

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Partial Pressures of O2 and CO2 in the body
(resting)

• Alveoli
• PO2 100 mm Hg
• PCO2 40 mm Hg
• Alveolar capillaries
• Entering the alveolar capillaries
• PO2 40 mm Hg (relatively low because this blood
  has just returned from the systemic circulation
  has lost much of its oxygen)
• PCO2 45 mm Hg (relatively high because the
  blood returning from the systemic circulation has
  picked up carbon dioxide)

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• Because of the differences in partial pressures
  of oxygen carbon dioxide in the systemic
  capillaries the body cells, oxygen diffuses
  from the blood into the cells, while carbon
  dioxide diffuses from the cells into the blood.
• Leaving the systemic capillaries
• PO2 40 mm Hg
• PCO2 45 mm Hg

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How are oxygen carbon dioxide transported in
the blood?

• Oxygen is carried in blood
• 1. bound to hemoglobin (98.5 of all oxygen in
  the blood)
• 2. dissolved in the plasma (1.5)
• Animation Quizzes hemoglobin

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A look from the top of Everest

• A view from the summit of Everest _at_ National
  Geographic Magazine

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Gas exchhange

• Howstuffworks "Gas Exchange"

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• Animation Quizzes gas exchange