1. Controlling the Internal Environment ThermoregulationOsmoregulationExcretion

2. Thermoregulation Ectothermic Endothermic Poikilothermic Homeothermic

3. Heat Exchange

4. Conduction - direct transfer of heat Convection - transfer of heat by the movement of air or water across a surface Radiation - emission of electromagnetic waves Evaporation - loss of heat from changing a liquid into a gas

5. Body Temp vs. Ambient Temp

6. Thermoregulation Adjustments Adjusting the rate of heat exchange –vasodilation/vasoconstiction –countercurrent heat exchange Cooling by evaporation Behavioral responses Changing the rate of metabolic heat production

7. Endothermic Animals Invertebrates –Large flying insects –Honeybees

8. Endothermic Animals Fish –Bluefin tuna –Swordfish –Great white shark Countercurrent heat exchange

9. Amphibians and Reptiles Most are ectothermic –regulate temperature by behavior

10. Mammals and Birds Contraction of muscles –moving –shivering Nonshivering thermogenesis –triggered by hormones

11. Feedback Mechanisms High body temperature –hypothalamus activates skin blood vessels to dilate and the sweat glands to produce sweat Low body temperature –hypothalamus activates skin blood vessels to constrict and the skeletal muscles to shiver

12. Temperature Range Adjustments Slow changes –acclimatization (enzymes and membranes) Fast changes –heat-shock proteins

13. Metabolic Cycles Torpor Hibernation Aestivation

14. Osmoregulation Osmoconformers vs. Osmoregulators

15. Osmoregulation Marine Fish –hypoosmotic –lose water to environment –must excrete salt –small amounts of urine Freshwater Fish –hyperosmotic –gain water from environment –must take in salt –large amounts of urine

16. Functions of the Excretory System Filtration Reabsorption Secretion Excretion

17. Excretion of Nitrogenous Waste Ammonia Urea Uric Acid

18. Invertebrate Structures Protonephridia (flame cells) network of closed tubules used mostly for osmoregulation found in platyhelminthes, some annelids, mollusk larvae

19. Invertebrate Structures Open tubules surrounded by a nephrostome Osmoregulation and excretion Found in annelids

20. Invertebrate Structures Malpighian Tubules Open into the digestive tract Osmoregulation and excretion Insects and terrestrial arthropods

21. Excretory Systems Origins in Vertebrates Pronephros, Mesonephros, Metanephros

22. Vertebrate Excretory Systems Pronephros –adult hagfish, embryonic fish, amphibians, reptiles, birds, mammals Mesonephros –adult lamprey, fish, amphibians, embryonic reptiles, birds, mammals Metanephros –adult reptiles, birds, mammals

24. The Human Excretory System Kidneys Ureters Urinary Bladder Urethra

26. Blood Filtrate to Urine Bowman’s Capsule and the Glomerulus –(filters the blood) Proximal tubule –reabsorbed (NaCl, Potassium, Water, Nutrients) –secretes ( ammonia) –regulates (pH)

27. Blood Filtrate to Urine Loop of Henle –Descending loop reabsorbed (water) –Ascending loop reabsorbed (NaCl)

28. Blood Filtrate to Urine Distal tubule –reabsorbed (NaCl, Water) –secrete (potassium) –regulate (pH) Collecting duct –reabsorbed (NaCl, Water, Urea)

30. Control of the Kidney Antidiuretic hormone (ADH) –water reabsorption Renin-angiotensin- aldosterone system (RAAS) –water reabsorption Atrialnatiuretic Factor (ANF) –inhibits the release of renin