1. Osmoregulation and Excretion
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Osmoregulation.ppt

2. Animal Life Multicellular organisms Internal circulation
Coordination, information transfer
Structural maintenance
Movement
Maintenance of homeostatic internal environment
Excretion of N waste
Regulation of pH
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Osmoregulation.ppt

3. How neurons conduct impulses:
Membrane potential (in neurons, muscle cells, etc.)
K+ diffuses out, Na+ diffuses in,
Na-K pump moves Na+ out & K+ in.
Cl-, phosphate, protein anions balance cations
“Resting potential” = mV
Imbalance of electrolytes results in serious disorders
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Osmoregulation.ppt

4. Osmoregulation Maintaining osmotic homeostasis
Balancing water and electrolyte concentrations
Maintains cell integrity
Maintains enzyme function
etc.
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Osmoregulation.ppt

5. Osmosis
Diffusion of water from high water concentration to lower water concentration.
Water loss
Water gain
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Osmoregulation.ppt

6. Osmosis Marine fish lose water by osmosis
Actively excrete salt to maintain homeostasis
Freshwater fish gain water by osmosis
Excrete excess water
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Osmoregulation.ppt

7. Nitrogenous wastes
Produced from metabolism of amino acids and nucleic acids
Ammonia
Urea
Uric acid
Guanine
Arachnids
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Osmoregulation.ppt

8. Nitrogenous wastes
Produced from metabolism of amino acids and nucleic acids
Uric acid from birds
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Osmoregulation.ppt

9. Nitrogenous waste & Osmoregulation
Same systems balance water and dispose of nitrogenous wastes
Protonephridia & “flame bulbs” in flatworms
Metanephridia in annelids
Malpighian tubules in arthropods
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Osmoregulation.ppt

10. Humans Body Water 75% of body weight in infant
60% of body weight in adult male
55% of body weight in adult female
Reasons for differences ??
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Osmoregulation.ppt

11. Osmoregulation Fluid compartments” Intracellular fluid
Extracellular fluid
Interstitial (tissue) fluid
Blood plasma
Lymph
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Osmoregulation.ppt

12. Osmoregulation Exchanges among compartments
Intracellular – interstitial
Diffusion, facilitated diffusion, osmosis, active transport
Interstitial fluid (excess)  lymph
Lymph  blood plasma
Plasma  interstitial fluid
Filtration from capillaries carries electrolytes & nutrients to cells
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Osmoregulation.ppt

13. Osmoregulation Regulation of blood plasma regulates all body fluids
Parts of osmoregulation
Filtration
Reabsorption
Secretion
Excretion (disposal)
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Osmoregulation.ppt

14. Kidney Nephron Renal corpuscle Tubule Glomerulus Bowman’s capsule
Proximal convoluted tubule
Loop of Henle
Distal convoluted tubule
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Osmoregulation.ppt

15. Nephron Filtration in renal corpuscle Afferent arteriole
Glomerular capillaries
Podocytes of Bowman’s capsule
Efferent arteriole
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Osmoregulation.ppt

16. Osmoregulation Reabsorption in proximal convoluted tubule
Active transport of Na+
Co-transport of glucose, amino acids, etc.
Cl- follows Na+
Osmosis of water
Diffusion of non-polar molecules
Diffusion of urea
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Osmoregulation.ppt

17. Osmoregulation Loop of Henle
Concentration of salts in medulla of kidney
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Osmoregulation.ppt

18. Osmoregulation
Reabsorption and tubular secretion in distal convoluted tubule
Recovery of NaCl, water,
Reabsorption of HCO3-
Secretion of H+, K+
pH regulation
Sources of metabolic H+
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Osmoregulation.ppt

19. Osmoregulation Collecting duct
Filtrate/urine makes one more pass through medulla
Final reabsorption (or not)
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Osmoregulation.ppt

20. Osmoregulation Antidiuretic hormone (ADH) Causes recovery of water
Absence  excretion of water
Important for water homeostasis
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Osmoregulation.ppt

21. Osmoregulation Diuretics
Ethyl alcohol
Beer, wine, liquor
Inhibits ADH release
Water NOT recovered
Caffeine
Coffee, tea, Coke, etc.
Inhibits Na+ transport
Sodium, water, etc. NOT recovered
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Osmoregulation.ppt

22. Urine Drainage Collecting ducts to Minor calyx Major calyx
Renal pelvis
Ureter
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Osmoregulation.ppt

23. Urine Drainage Ureter to Urinary bladder Detrusor muscle Urethra
Smooth muscle of bladder
Urethra
internal sphincter
external sphincter
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Osmoregulation.ppt

24. Urine Drainage Urethra internal sphincter external sphincter Female
3-4 cm
Anterior to vagina
Male
15-20 cm
Passes through prostate and penis
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Osmoregulation.ppt