ALVEOLI: Tiny air sacs where gas exchange occurs
STRUCTURE OF ALVEOLI:
Diagram showing the Structure of Alveoli in Lungs
ADAPTATIONS:
FEATURE
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ADAPTATION
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FOLDED ALVEOLI
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Folded to increase surface area to volume ratio for diffusion of gases, therefore increasing rate of gas exchange
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THIN CELL WALLS
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Thin cell walls (one cell thick) to minimise distance of diffusion of gases, therefore increasing the rate of gas exchange
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DENSE CAPILLARY NETWORK
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Alveoli surrounded by dense capillary network to provide rich blood supply and creates a strong concentration gradient for the diffusion of gases, therefore increasing the rate of gas exchange
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thanks so much love ya
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ReplyDeleteThe biology here is poor.. a feature is an adaptation... a physical thing.. alveoli do not have cell walls and they are not folded so none of the features would get a mark in the exam. The adaptations column shows explanations and adaptations. As a teacher, you need to check your facts
ReplyDeletecorrect, instead you should mention that there are only 5 membranes to diffuse through, keeping a short distance; and should perhaps mention the surfactants that help dissolve the oxygen/carbon dioxide; and the continued ventilation and high blood flow through the capillaries, maintaining a high concentration gradient
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