Why is diffusion alone enough to supply the needs of single-celled organisms?
1: The metabolic activity is usually low, so the oxygen demands and carbon dioxide production is relatively low.
2: The surface area to volume ratio is large. The smaller the organism, the greater the volume ratio and less distance diffusion occurs over
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What are the 4 main characteristics of exchange surfaces?
1: Increased surface area
2: Thin layers
3: Good blood supply
4: Ventilation
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What are the 3 important features of the nasal cavity?
1: Large surface area - good blood supply
2: A hairy lining - secretes mucus to trap dust and bacteria
3: Moist surfaces - increases the humidity of the incoming air
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What is the trachea?
It is the main airway carrying clean, warm, moist air from the nose down into the chest.
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What is the structure of the trachea?
It is a wide tube supported by incomplete rings of strong flexible cartilage, which prevent it from collapsing.
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what is the function of the smooth muscle in the walls of the bronchioles?
When the smooth muscle contracts, the bronchioles constrict and when it relaxes, the bronchioles dilate, which changes the amount of air reaching the lungs.
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Other cards in this set
Card 2
Front
What are the 4 main characteristics of exchange surfaces?
Back
1: Increased surface area
2: Thin layers
3: Good blood supply
4: Ventilation
Card 3
Front
What are the 3 important features of the nasal cavity?
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