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25 Cards in this Set
- Front
- Back
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Osmosis |
water moves across area of high [ ] of solute to low [ ] of solute |
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Osmoregulation |
- process of regulating [ ] of solute & h2o - osmolarity: total [ ] of osmotically active particles in solution - hypo-osmotic: low [ ] to another - hyper-osmotic: high [ ] to another - changes in salt [ ] lead to osmosis - water DOES NOT actively transport - moves when change of salt [ ] |
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Excretory System |
1) maintain volume, [ ], composition & extracellular fluids 2) excrete waste |
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Process of Excretion |
1) Filtration 2) Secretion 3) Reabsorption |
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Osmoconformers |
- equilibrate extracellular fluid osmolarity with ocean water - most marine invertebrate are conformers - very salty environment, water moves OUT of body - match environment |
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Osmoregulators |
- maintain extracellular fluid osmolarities lower than seawater - most marine vertebrates - use energy to keep own level |
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Marine Environment for Osmoregulation |
- Environment: very salty - Water Movement: water moves OUT of body - Example: body hypo-osmotic/tonic to enviro - Problem: water loss & salt gain thru gills - Solution: drink seawater, actively transport salt out, produce little urine (want to keep h2o) |
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Freshwater Environment for Osmoregulation |
- Environment: not salty - Water Movement: move INTO body - most freshwater animals have lower osmotic [ ] than marine animals - Example: body hyper-osmotic/tonic to enviro - Problem: water gain & salt loss thru gills - Solution: produce a lot of urine, actively transport salt IN, does not drink
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Terrestrial Environment for Osmoregulation |
- Environment: No Water - Desiccation (extreme dryness) major threat - Many adaptions for minimizing water loss - Example: - Problem: lose water continuously - Solution: body coverage lessen loss, drinking & eating moist food, kidney [ ] urine |
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Nitrogen Excretion |
- proteins & nucleic acid break down, nitrogen turns into ammonia - very toxic - Three ways 1) Ammonia: some animal secrete ammonia directly 2) Urea: some animal convert to less toxic before excretion (needs energy) 3) Uric Acid: some animal convert to less toxic before excretion (needs energy) |
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Ammonia |
- highly soluble in water so mostly aquatic animals; ammonotelic - must be highly diluted - invertebrate: NH3 lost across surface - freshwater: exchange Na+ for NH3 |
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Urea |
- x100k less toxic than NH3 - mammals, amphibians, shark, etc; ureotelic - less water needed to excrete urea - requires energy to produce |
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Uric Acid |
- less toxic than NH3 - insects, snails, birds, reptiles; uricotelic - insoluble in water, creates paste like solids - more energy than urea to produce |
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Excretory Organs |
- Filtration: extracellular fluid filtered to rid of cells & large molecules, driven by blood pressure - Secretion: specialized cell secretes molecule/ion into filtrate - Reabsorption: molecules & water may be reabsorbed |
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Invertebrate Excretory System |
Three Types 1) Protonephridia 2) Metanephridia 3) Malpighian Tubules |
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Protonephridia |
- Flatworm - excrete water & conserve salt - Flame Cell: beating cilia that creates pressure - Tubule: alters composition of extracellular fluid
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Metanephridia |
- Earthworm - Metanephridia: segment that coelomic fluids go into |
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Malpighian Tubules |
- does not use pressure difference - use active transport |
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Kidney |
- Function 1) filter toxin out of blood & transport into urinary bladder 2) water & salt balance - Structure 1) Renal Cortex: outermost 2) Renal Medulla: middle section 3) Renal Pelvis: Inner core
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Nephron |
- Cortex: Peritubular Capillaries - Medulla: Vasa Recta - lined with transport epithelia Structure: 1) Bowmans Capsule (filtration) 2) Proximal & Distal Tubules (Reabsorption) 3) Loop of Henle (Diffusion & Osmosis) Two Types 1) Cortical Nephrons: confined to cortex 2) Juxtamedullary Nephrons: loop of Henle into medulla KEY TO PRODUCE HYPER-OSMOTIC URINE Function: - CREATE A [ ] GRADIENT TO ALLOW WATER & SALT ABSORPTION
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Filtration of Urine |
- Bowman's Capsule: fluid enters - Glomerular: blood enters & create arterial presure to force fluid into proximal tube - Proximal Tube: fluid contains salt, glucose, aa, urea, vitamins & water; transport out of filtrate - Loop of Henle: establishes interstitual fluid [ ] gradient in medulla - Distal Proximal Tubule: selective reabsorbtion - Collecting Duct: water passively diffuse out (thx to henle [ ]), water gets collected by vasa vecta, tail leaky to urea which contributes to [ ] |
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Looope of Henle |
- Descending Limb: permeable ONLY to water, water leaves - Thin Ascending Limb: permeable ONLY to salt, salt leaves - Thick Ascending Limb: permeable ONLY to salt, actively transports salt out
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Regulation |
- amount of water & salt secreted controlled by hormones - Two Types: 1) Antidiruretic Hormone (ADH) 2) Renin-Angiotenisin-Aldosterone (RAAS) |
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ADH |
- responds to osmolarity & blood pressure 1) release antidiuretic hormone 2) insert aquaporins 3) increase water permeability 4) more water reabsorbed - urine volume decreases |
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RAAS |
- responds to reduced blood volume/pressure 1) release enzyme renin 2) convert angiotensinogen -> angiotensin I 3) form angiotensin II or angiotensin - constricts arteriole to increase pressure - release aldosterone to stimulate sodium reabsorption - stimulate thirst, increase water = increase blood volume = increase blood pressure |
