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respiratory structures and organs in animals_56450.ppt
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- 2. RESPIRATION • Why theneed for gas exchange (respiration)? Gas exchange involves uptake of O2 and release of CO2 • What is oxygen used for? Aerobic respiration uses energy of electrons to produce ATP Energy-depleted electrons (and associated proton in H) accepted by O2 to form H2O • Where does CO2 come from? CO2 released when glucose broken down to release electrons in the Kreb’s Cycle
- 3. • Respiration involvesdiffusion RESPIRATION • Respiration requires diffusion of O2 and CO2 across cell membranes • Diffusion of O2 and CO2 is passive • Occurs if different concentrations of O2 or CO2 on either side of membrane
- 4. Aquatic Gas Exchange •Advantage: • Keeping surface moist is no problem • Disadvantage: • O2 concentrations in water are low, especially in warmer and saltier environments
- 5. Terrestrial Gas Exchange •Advantages: • O2 diffuses faster in air • Air contains much more O2 than water • Disadvantage: • Surfaces must be internal to avoid loss of water due to evaporation
- 6. Respiratory Surface • Mustaccommodate diffusion of CO2 out, O2 in • Typically very thin • Always moist or wet • If they dry out, they cannot function
- 7. Protists and LessComplex Animals • Once again, less complex organisms do not need complex organ systems • Gas exchange takes place due to diffusion
- 8. 4 Types ofRespiratory Organs • Skin • Tracheae • Gills • Lungs
- 9. Skin • For skinbreathers, respiratory surface = body covering • Must live in moist or wet places • Must maintain high surface area to volume ratio • Keep body small • Keep body flat • Or both
- 10. Gas Transport: Skin •Gases transported from skin to cells by blood or body fluids
- 11. Insects • Have aseries of openings along their sides called SPIRACLES • Air ducts in insects; Tubes called TRACHEA lead from spiracles to all of the body tissues • Smallest branches = tracheoles have liquid inside • Extend directly to cells, Gas transfer directly to cells! • Open circulatory system does not transport O2 and CO2
- 13. Gills • Respiratory surface= thin filaments • Typically found in aquatic organisms • Fish • Crayfish, crabs, lobsters, • Clams
- 14. Fish • Most fishbreathe with gills – feathery filaments that contain capillaries and a large surface area for gas exchange • They breathe by pumping water through the mouth, over gill filaments and out through slits in the sides of the pharynx • Double Pump System: by decreasing pressure in mouth, water is forced in; by increasing pressure in mouth, water is forced out through the opercula
- 15. Advantages of Gillsto Fish • Because the gills are so VASCULAR and have a large surface area, gas exchange can happen adequately • Increase surface area to volume ratio • Overcome shape, size limitations associated with skin breathers
- 16. Counter Current Exchangein Fish • “Counter-current” = two fluids moving in opposite directions: Water one way and Blood the other way • “Exchange” = transfer of energy or materials
- 17. d flow increasesthe efficiency of ater n from high to low concentration ures gradient exists continually an theoretically approach 100% Why Counter Current?
- 19. Lungs • Biggest animalsEVER (blue whales) have lungs! • This tells us that for very large animals, lungs are better than gills, tracheae, skin
- 20. Bird Lungs • Havecounter-current exchange • Can extract oxygen from air thin enough to kill a human! • One-way flow of air through lung • No “dead air space” left after exhaling
- 21. Air Sacs inBird
- 22. • Basic typesof respiratory systems in animals Respiratory Systems How do organisms ‘solve’ common problems? – Cutaneous (skin) respiration • How to maximize rate of diffusion? – thin skin • What constraints are associated with this system? – Increase surface area with parapodia – cannot get too large – No energetically expensive activities – Use cilia on skin to move water • Phyla Annelida
- 23. • Basic typesof respiratory systems in animals Respiratory Systems How do organisms ‘solve’ common problems? – Direct diffusion through cells • How to maximize rate of diffusion? – thin cell or tissue layers • What constraints are associated with this system? – circulate water across outer surface – cannot be large in size • Phyla Cnidaria – Cannot be involved in energy- consuming activities
- 24. • Basic typesof respiratory systems in animals Respiratory Systems How do organisms ‘solve’ common problems? – External Gills • Phylum Chordata – thin gills • What constraints are associated with this system? – Increase surface area with feather-like arrangement of gills and by using skin as additional respiratory surface – Must be in constant motion or in water current – Tissue delicate and cannot be protected • larval fish and amphibians (also in some adult salamanders) • How to maximize rate of diffusion? – Relatively small body size
- 25. • Basic typesof respiratory systems in animals Respiratory Systems How do organisms ‘solve’ common problems? – Internal (covered) Gills • Phylum Chordata – Buccal cavity (mouth) • Two cavities act together to draw water across surface of gills – Opercular cavity (gill chamber below gill cover or operculum) • Bony fish (Class Osteichthyes) • Internal gills enclosed within body chambers that move water over gills
- 26. • Basic typesof respiratory systems in animals Respiratory Systems How do organisms ‘solve’ common problems? – Internal (covered) Gills – thin gills (blood vessels close to surface of gill) – Increase surface area of gill with feather-like arrangement – Uses counter-current system in gills to increase P • How to maximize rate of diffusion? – Constantly ‘pump’ water across gills with buccal and opercular cavities
- 27. • Basic typesof respiratory systems in animals Respiratory Systems How do organisms ‘solve’ common problems? – Structure of Internal Gills