Flashcards
Gas Exchange in Mammals
Cards in this deck (5)
- 1What are the steps in the mechanism of gas exchange in mammalian lungs? [6]Nostril
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Nasal Cavity
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Trachea
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Bronchi
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Bronchioles
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Alveoli - 2Why must gases be exchanged in such high volumes in humans? [2]1~ Humans have a small surface area:volume ratio.
2~ Humans are warm blooded and require high metabolic and respiratory rates. - 3How is diffusion made efficient across the alveoli? [4][] Red blood cells are flattened against the wall of the capillaries
[] Breathing/blood flow maintains concentration gradient
[] Alveoli/capillaries have large SA:V ratio
[] Alveoli/capillaries have thin walls - 4Explain, step-by-step, the mechanism of inhalation. [7]~ Internal intercostal muscles relax
~ External intercostal muscles contract
~ Ribs are pulled upwards and outwards
~ The diaphragm flattens
~ The volume of the thorax increases
~Pressure in lungs < Atmospheric pressure
~ Air is forced into the lungs - 5Explain, step-by-step, the mechanism of exhalation. [7]~ Internal intercostal muscles contract
~ External intercostal muscles relax
~ Ribs move downwards and inwards
~ The diaphragm domes
~ The volume of the thorax decreases
~Pressure in lungs > Atmospheric pressure
~ Air is forced out of the lungs
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- AS level Biology (Exchange) Flashcards on Gas Exchange in Mammals, created by Melissa O'Mahony on 06/03/2017.
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- Melissa O'Mahony
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