1. Homeostasis Maintain a “steady state” or internal balance regardless of external environment Fluctuations above/below a set point serve as a stimulus; these are detected by a sensor (receptor), sends a signal and triggers a response The response returns the variable to the set point © 2011 Pearson Education, Inc.

3. Negative Feedback “More gets you less.” Return changing conditions back to set point Examples: –Temperature –Blood glucose levels –Blood pH Plants: response to water limitations Positive Feedback “More gets you more.” Response moves variable further away from set point Stimulus amplifies a response Examples: –Lactation in mammals –Onset of labor in childbirth Plants: ripening of fruit

4. Positive or Negative Feedback? Cyclin protein is produced at the beginning of the G2 phase. Cyclin production continues to increase as the cell moves through the G2 phase. Cyclin production reaches is maximum just before the start of the M phase. 4

5. Positive or Negative Feedback? When ATP levels are high in a cell, enzymes involved in glycolysis are allosterically inhibited. This results in a reduction in the amount of ATP produced. 5

6. Do Now: Animals get energy from FOOD Digestion provides monomers required for… ATP synthesis, cellular work, and biosynthesis (growth, repair, reproduction) 6

7. 7 What is thermoregulation? Maintaining of internal temperatures in an organism endotherms and ectotherms 7

8. Are these endotherms or ectotherms? ENDOTHERMS 8

9. Characteristics of Endotherms: Maintain constant internal body temp Generate heat from metabolism (C.R.) Requires more energy Higher Metabolic Rates –Highest in very COLD temps (why?) –Negative feedback mechanism! Birds and Mammals 9

10. Characteristics of Ectotherms Internal temp changes with the environmental temp Get heat from external sources Lower metabolic rates Less food intake Behavioral adaptations Play an impt role All other animals 10

11. Figure 40.10 How does this graph characterize the relationship between environmental temperature and body temperature of endotherms and ectotherms?

12. An organisms metabolic rate is the sum of all energy requiring chemical reactions. How can scientists measure the metabolic rate of organisms? Cell Respiration Rates! Oxygen consumption CO2 production Heat Loss 12

13. Comparing the energy expenditures in various sized endotherms and ectotherms Observations: 13

14. How does the size of an organism affect is metabolic rate? (Comparison of various mammals - ENDOTHERMS) Observations and Predictions 14

15. Five adaptations for thermoregulation: Insulation (skin, feather, fur, blubber) Circulatory adaptations (countercurrent exchange) Cooling by evaporative heat loss (sweat) Behavioral responses (shivering, shade, basking) Adjusting metabolic heat production © 2011 Pearson Education, Inc.

16. 1. Insulation is provided by –hair, –feathers, and –fat layers. 25.3 Thermoregulation involves adaptations that balance heat gain and loss © 2012 Pearson Education, Inc.

17. 2. Circulatory adaptations include –increased or decreased blood flow to skin and –Heat moves from high to low temps between arteries and veins (countercurrent). 25.3 Thermoregulation involves adaptations that balance heat gain and loss © 2012 Pearson Education, Inc.

18. 3. Evaporative cooling may involve –sweating, –panting, or –spreading saliva on body surfaces. 25.3 Thermoregulation involves adaptations that balance heat gain and loss © 2012 Pearson Education, Inc.

19. Figure 25.3_1 Heat dissipation (Via ear flapping) Evaporative Cooling

20. 4. Behavioral responses –are used by endotherms and ectotherms and –include »moving to the sun (basking) or shade, »migrating, and »bathing. 25.3 Thermoregulation involves adaptations that balance heat gain and loss © 2012 Pearson Education, Inc. Color changes

21. 5. Increased metabolic heat production occurs when –Increased cell respiration, –birds and mammals shiver, –organisms increase their physical activity, and –honeybees cluster and shiver. 25.3 Thermoregulation involves adaptations that balance heat gain and loss © 2012 Pearson Education, Inc.

22. Figure 25.3_UN01

23. What are these organisms doing???

24. Torpor and Energy Conservation Torpor is a physiological state in which activity is low and metabolism decreases Save energy while avoiding difficult and dangerous conditions Hibernation: torpor during winter Estivation: summer torpor © 2011 Pearson Education, Inc.

25. Figure 25.3_UN01

26. Circulatory adaptations include –increased or decreased blood flow to skin and –countercurrent heat exchange, with warm and cold blood flowing in opposite directions. 25.3 Thermoregulation involves adaptations that balance heat gain and loss © 2012 Pearson Education, Inc.

27. Figure 25.3_1 Ear flapping to release excess heat; water spray for evaporative cooling

28. Figure 25.3_2 Blood from body core in artery Blood returning to body core in vein Blood from body core in artery Blood returning to body core in vein 35  30  20  10  33  C 27  18  99

29. Figure 40.12 What is countercurrent heat exchange? Animation

30. What is countercurrent heat exchange? Prevents the loss Of a large amount of Heat by transferring Heat from warm Blood to cooler Adjacent blood 30 Animation

31. Which body systems are involved in mammalian thermoregulation? Integumentary (skin) Muscular Circulatory 31

32. Figure 40.16 When body temperature decreases: Shivering and Constriction of Blood Vessels When body temperature increases: Sweating and dilation of blood vessels

33. OSMOREGULATION AND EXCRETION © 2012 Pearson Education, Inc.

34.  Osmoregulation is the homeostatic control of the uptake and loss of water and solutes such as salt and other ions.  Osmosis is one process whereby animals regulate their uptake and loss of fluids. 25.4 Animals balance the level of water and solutes through osmoregulation © 2012 Pearson Education, Inc.

35. 25.4 Animals balance the level of water and solutes through osmoregulation Osmoconformers –have body fluids with a solute concentration equal to that of seawater, –face no substantial challenges in water balance, and –include many marine invertebrates. © 2012 Pearson Education, Inc.

36. 25.4 Animals balance the level of water and solutes through osmoregulation  Osmoregulators have body fluids whose solute concentrations differ from that of their environment, must actively regulate water movement, and include –many land animals, –freshwater animals such as trout, and –marine vertebrates such as sharks. © 2012 Pearson Education, Inc.

37. 25.4 Animals balance the level of water and solutes through osmoregulation  Freshwater fish gain water by osmosis (mainly through gills), lose salt by diffusion to the more dilute environment, take in salt through their gills and in food, and excrete excess water in dilute urine. © 2012 Pearson Education, Inc.

38. Figure 25.4_1 Fresh water Excretion of large amounts of water in dilute urine from kidneys Uptake of salt ions by gills Uptake of some ions in food Osmotic water gain through gills and other parts of body surface

39. Saltwater fish –lose water by osmosis from the gills and body surface, –drink seawater, and –use their gills and kidneys to excrete excess salt. 25.4 Animals balance the level of water and solutes through osmoregulation © 2012 Pearson Education, Inc.

40. Figure 25.4_2 Gain of water and salt ions from food and by intake of seawater Osmotic water loss through gills and other parts of body surface Salt water Excretion of excess ions and small amounts of water in concentrated urine from kidneys Excretion of salt from gills

41. Land animals –face the risk of dehydration, –lose water by evaporation and waste disposal, –gain water by drinking and eating, and –conserve water by reproductive adaptations, behavior adaptations, waterproof skin, and efficient kidneys. 25.4 Animals balance the level of water and solutes through osmoregulation © 2012 Pearson Education, Inc.

42. 25.5 EVOLUTION CONNECTION: A variety of ways to dispose of nitrogenous wastes has evolved in animals Metabolism produces toxic by-products. Nitrogenous wastes are toxic breakdown products of proteins and nucleic acids. Animals dispose of nitrogenous wastes in different ways. © 2012 Pearson Education, Inc.

43. Ammonia (NH 3 ) is –poisonous, –too toxic to be stored in the body, –soluble in water, and –easily disposed of by aquatic animals. 25.5 EVOLUTION CONNECTION: A variety of ways to dispose of nitrogenous wastes has evolved in animals © 2012 Pearson Education, Inc.

44. Urea is –produced in the vertebrate liver by combining ammonia and carbon dioxide, –less toxic, –easier to store, and –highly soluble in water. 25.5 EVOLUTION CONNECTION: A variety of ways to dispose of nitrogenous wastes has evolved in animals © 2012 Pearson Education, Inc.

45. Uric acid is –excreted by some land animals (insects, land snails, and many reptiles), –relatively nontoxic, –largely insoluble in water, –excreted as a semisolid paste, conserving water, but –more energy expensive to produce. 25.5 EVOLUTION CONNECTION: A variety of ways to dispose of nitrogenous wastes has evolved in animals © 2012 Pearson Education, Inc.

46. Figure 25.5 Proteins Ammonia Nitrogenous bases NH 2 (amino groups) Nucleic acids Urea Uric acid Mammals, most amphibians, sharks, some bony fishes Birds and many other reptiles, insects, land snails Most aquatic animals, including most bony fishes Amino acids

47. 25.6 The urinary system plays several major roles in homeostasis The urinary system –forms and excretes urine and –regulates water and solutes in body fluids. In humans, the kidneys are the main processing centers of the urinary system. © 2012 Pearson Education, Inc.

48. Nephrons –are the functional units of the kidneys, –extract a fluid filtrate from the blood, and –refine the filtrate to produce urine. Urine is –drained from the kidneys by ureters, –stored in the urinary bladder, and –expelled through the urethra. 25.6 The urinary system plays several major roles in homeostasis © 2012 Pearson Education, Inc. Animation: Nephron Introduction

49. Figure 25.6 Aorta Kidney The urinary system Inferior vena cava Renal artery (red) and vein (blue) Ureter Urethra Urinary bladder Renal cortex Renal medulla Renal pelvis Ureter The kidney Proximal tubule Bowman’s capsule Tubule Collecting duct To renal pelvis Branch of renal artery Branch of renal vein Renal cortex Renal medulla Capillaries Glomerulus Distal tubule From another nephron Bowman’s capsule Arteriole from renal artery Arteriole from glomerulus Branch of renal vein Loop of Henle with capillary network Detailed structure of a nephron 1 3 2 Orientation of a nephron within the kidney Collecting duct

50. Figure 25.6_1 Aorta Kidney The urinary system Inferior vena cava Renal artery (red) and vein (blue) Ureter Urethra Urinary bladder

51. Figure 25.6_2 Renal cortex Renal medulla Ureter Renal pelvis The kidney

52. Figure 25.6_3 Bowman’s capsule Tubule Collecting duct To renal pelvis Branch of renal artery Branch of renal vein Renal cortex Orientation of a nephron within the kidney Renal medulla

53. Figure 25.6_4 Proximal tubule Glomerulus Distal tubule Collecting Duct From another nephron Bowman’s capsule Arteriole from renal artery Arteriole from glomerulus Branch of renal vein Loop of Henle with capillary network Detailed structure of a nephron Capillaries 1 3 2

54. 25.7 Overview: The key processes of the urinary system are filtration, reabsorption, secretion, and excretion Filtration –Blood pressure forces water and many small molecules through a capillary wall into the start of the kidney tubule. Reabsorption –refines the filtrate, –reclaims valuable solutes (such as glucose, salt, and amino acids) from the filtrate, and –returns these to the blood. © 2012 Pearson Education, Inc.

55. Figure 25.7 Reabsorption SecretionExcretion Urine To renal vein Filtration Nephron tubule Capillary Interstitial fluid H 2 O, other small molecules Bowman’s capsule From renal artery

56. Figure 25.7_1 Filtration Nephron tubule Capillary Interstitial fluid H 2 O, other small molecules Bowman’s capsule From renal artery

57. Figure 25.7_2 ReabsorptionSecretion Excretion Urine To renal vein Capillary Nephron tubule

58. Substances in the blood are transported into the filtrate by the process of secretion. By excretion the final product, urine, is excreted via the ureters, urinary bladder, and urethra. 25.7 Overview: The key processes of the urinary system are filtration, reabsorption, secretion, and excretion © 2012 Pearson Education, Inc.

59. Figure 25.7 Reabsorption SecretionExcretion Urine To renal vein Filtration Nephron tubule Capillary Interstitial fluid H 2 O, other small molecules Bowman’s capsule From renal artery

60. Reabsorption in the proximal and distal tubules removes –nutrients, –salt, and –water. pH is regulated by –reabsorption of HCO 3 – and –secretion of H +. 25.8 Blood filtrate is refined to urine through reabsorption and secretion © 2012 Pearson Education, Inc.

61. High NaCl concentration in the medulla promotes reabsorption of water. 25.8 Blood filtrate is refined to urine through reabsorption and secretion © 2012 Pearson Education, Inc. Animation: Bowman’s Capsule and Proximal Tubule Animation: Collecting Duct Animation: Effect of ADH Animation: Loop of Henle and Distal Tubule

62. Figure 25.8 Bowman’s capsule Blood Nutrients H 2 O NaCl Proximal tubule Some drugs and poisons Cortex Medulla Interstitial fluid Loop of Henle H2OH2O Filtrate composition Reabsorption Filtrate movement Secretion Distal tubule 1 2 NaCl Urea H2OH2O 3 KK HH Collecting duct Urine (to renal pelvis) H2OH2O NaCl HCO 3  H 2 O Salts (NaCl and others) HCO 3  H  Urea Glucose Amino acids Some drugs HCO 3  HH

63. Figure 25.8_1 Blood Filtrate composition Reabsorption Filtrate movement Secretion Bowman’s capsule Nutrients H 2 O NaCl HCO 3  Proximal tubule Some drugs and poisons Cortex Medulla HH H 2 O Salts (NaCl and others) HCO 3  H  Urea Glucose Amino acids Some drugs

64. Figure 25.8_2 Reabsorption Filtrate movement Secretion Nutrients NaCl HCO 3  Some drugs and poisons Cortex Medulla Proximal tubule Interstitial fluid Loop of Henle H2OH2O NaCl Urea H2OH2O Collecting duct Urine (to renal pelvis) Distal tubule H2OH2O NaCl HCO 3  1 3 2 H2OH2O HH H K  

65. Antidiuretic hormone (ADH) regulates the amount of water excreted by the kidneys by –signaling nephrons to reabsorb water from the filtrate, returning it to the blood, and –decreasing the amount of water excreted. Diuretics –inhibit the release of ADH and –include alcohol and caffeine. 25.9 Hormones regulate the urinary system © 2012 Pearson Education, Inc.

66. Kidney failure can result from –hypertension, –diabetes, and –prolonged use of common drugs, including alcohol. A dialysis machine –removes wastes from the blood and –maintains its solute concentration. 25.10 CONNECTION: Kidney dialysis can be lifesaving © 2012 Pearson Education, Inc.

67. Figure 25.9 Line from artery to apparatus Pump Tubing made of a selectively permeable membrane Dialyzing solution Fresh dialyzing solution Used dialyzing solution (with urea and excess ions) Line from apparatus to vein

68. Figure 25.9_1 Line from artery to apparatus Pump Tubing made of a selectively permeable membrane Dialyzing solution Fresh dialyzing solution Used dialyzing solution (with urea and excess ions) Line from apparatus to vein

69. Figure 25.9_2

70. 1.Explain how bear physiology adjusts during dormancy. 2.Describe four ways that heat is gained or lost by an animal. 3.Describe five categories of adaptations that help animals thermoregulate. 4.Compare the osmoregulatory problems of freshwater fish, saltwater fish, and terrestrial animals. You should now be able to © 2012 Pearson Education, Inc.

71. 5.Compare the three ways that animals eliminate nitrogenous wastes. 6.Describe the structure and functions of the human kidney. 7.Explain how the kidney promotes homeostasis. 8.Describe four major processes that produce urine. 9.Describe the key events in the conversion of filtrate into urine. 10.Explain why a dialysis machine is necessary and how it works. You should now be able to © 2012 Pearson Education, Inc.

72. Figure 25.4_UN01

73. Figure 25.UN01 35  33  C 27  30  20  10  99 18 

74. Figure 25.UN02 Freshwater Fish Osmosis Gain Water Drinking, eating Saltwater Fish Land Animal Evaporation, urinary system Drinking Osmosis Excretion Pump in Excrete, pump out Lose Water Salt

75. Figure 25.UN03 Urea

76. Figure 25.UN04 Kidney Ureter Bladder

77. Figure 25.UN05 Homeostasis involves processes of (a) (b) (d) animal may be maintains balance of water and solutes human kidney both done by (c) involves removal of nitrogenous wastes (e) (f) (g) form may be depends on reproduction (where embryo develops) (i) may be endotherm mechanisms include requirements depend on mechanisms mostly (h) heat production, insulation, countercurrent heat exchange ocean, fresh water, land

78. Figure 25.UN06 (a) (b) Bowman’s capsule From renal artery To renal vein Glomerulus Tubule Capillaries Loop of Henle (d) (c) Collecting duct