BIO 203 Lecture 21

BIO 203 Lecture 21 - • Aquatic animals – advantage that...

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Lecture 21 – Dilger April 17 th 2007 Respiration Boyle’s law – showed that both animals and flames in a vacuum indicating that air contained something that is required both to maintain life and to keep a candle burning Respiratory surface Site of o2/co2 exchange Surfaces are moist Must be bathed in water to maintain plasma membrane O2 and co2 must dissolve in water before exchange takes place Large surface area needed for exchange Different solutions have evolved depending on size and habitat of animal Coupled respiratory and circulatory systems Very successful strategy that has evolved in animals is a 2 step exchange process involving circulatory system Step 1 – exchange between respiratory medium and circulatory system Step 2 – exchange between circulatory system and interstitial fluid bathing cells Circulatory system acts as a transport system for gases
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Unformatted text preview: • Aquatic animals – advantage that respiratory systems stay moist, but oxygen concentration in water is pretty low, so efficient exchange needed • Gills are out folding (evaginations) of the body surface, could be all over body, or restricted to a local region (crayfish, losters, fish) • Exchange at gills maximized by ventilation – increase water flow over gills – counter-current exchange • Ventilation – any method of increasing contact between the respiratory medium and surface • Paddle-like appendages to push water over gills, and also swimming increases water flow over gills – “ram ventilation” – ventilation • Counter current exchange system – water flows over the lamella opposite to the flow of blood so there is a diffusion gradient and exchange of gases occurs • Read about alveoli and other shit in chapter 42 •...
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This note was uploaded on 04/08/2008 for the course BIO 328 taught by Professor Cabot during the Spring '07 term at SUNY Stony Brook.

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