12. osmoregulation & excretion - animal...
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Zoology 430: Animal Physiology
12. Osmoregulation & Excretion
1Zoology 430: Animal Physiology
12. Osmoregulation & Excretion
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Zoology 430: Animal Physiology
Water flows freely through cell membranes
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Aquaporin is a channel protein: Big pukas letting H2O through (image below)Channels do not require/use any energy equivalents (ATP)Ions have a harder time getting through membrane (Semi permeable membrane)
In general: Ions “trapped” in cells, water flows through to balance concentration gradient
Aquaporin
Zoology 430: Animal Physiology
Body Solids and Fluids
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Extracellular and Intracellular Ions
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Zoology 430: Animal Physiology
Osmoregulatory strategies
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Free ride? No - must maintain intracellular function - balance.
Expensive?Yes - done by active transport= ATP!, but maintains stable internal environment
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Freshwater 10-50
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Zoology 430: Animal Physiology
Intracellular Ions
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Intracellular solutes - K+ and organic solutes
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Too little water, has to drink salty water
Too much water, has to absorb salt
Zoology 430: Animal Physiology
Tubular Excretion
Blood Flow
Renal Tubule (e.g., Nephron)
Renal Blood Supply
RPF [P]
[P] Renal Plasma Flow
Filtrate
[F] Glomerular Filtration Rate
GFR [F]
Secretion Reabsorption
[U] Urine Flow Rate
UrineUFR [U]
Osmo-conentration
(e.g., glomerulus & Bowman’s Capsule)
(proximal tubule)
(distal tubule)
(collecting duct)
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