Chapter 1  REVIEW QUESTIONS

Some of these questions have been taken from other Animal Physiology pages. All questions require answers that fully explain the conditions, causes, and results.

  1. What is physiology?
  2. What are some of the ways an individual’s phenotype can change?
  3. What is the difference between a physiological regulator and a physiological conformer? Give an example of each.
  4. What are the benefits and costs of conformation?
  5.  What are the benefits and costs of regulation?
  6. What is the main the benefit of physiological regulation?
  7. Be able to draw a graph similar to Fig. 1.6 or 1.7 to illustrate conformity and/or regulation. Which graph represents homeostasis? Why
  8. What does Figure 1.7 indicate about salmon?
  9. Who are Claude Bernard and Walter Cannon? What is their importance?
  10. Why does homeostasis require negative feedback control?
  11. Explain and give an example example of a negative feedback loop.
  12. Explain and give an example example of a positive feedback loop.
  13. In physiological systems, why are positive feedback loops of limited duration?
  14. Physiological responses can be categorized as being acute, chronic, or evolutionary. Define each, in terms of what is going on at the molecular (e.g., gene and/or protein) level, and explain why each is occurring.
  15. Is acclimation an acute, chronic, or evolutionary response? Explain why it is this type of response. Explain why it is not each of the other two physiological responses.
  16. What is the difference between a chronic and an evolutionary (adaptation) physiological response? Give an example of each in response to the same physiological challenge.
  17. What is the difference between a chronic and an acute response to environmental conditions? Give an example of each in response to the same physiological challenge.
  18. Explain what is meant by the following two statements. Tibetans have adapted to living in the Himalayan mountains at high elevations. When I go to Tibet to see the Himalayas, I acclimate to living at high elevations.
  19. Figure 1.8 is an example of physiological responses of 24 men to heat and excercise over seven days.
    1. What part of the graph represents the acute response?  Give some examples of acute responses that may have occurred.
    2. What part of the graph represents acclimation.  Is acclimation an example of an accute, chronic, or evolutionary response?  Justify your answer.
    3. Give two examples of the physiological changes (biochemical/cellular) that took place during acclimation that are examples of phenotypic plasticity
    4. At day 7 has an evolutionary response occurred? Explain why or why not.
    5. In Figure 1.8, what part of the graph represents the chronic response?  The acute response?  What happened in terms of physiological response from day 1 to 6 and after day 6?
    6. Explain why Figure1.8 illustrates an example of phenotypic plasticity.Give two examples of the physiological changes (biochemical/cellular) that took place from day 1 to day 7 that are examples of phenotypic plasticity
    7.  

  20. Fig. 1.8
  21. Why were log scales used in figure 1.9 (gestation period versus body mass)?
  22. From the data on this graph, compare actual versus expected gestation period for several species.  Which of these would you find interesting to investigate?  Why?
  23. Calculate the slope of the equation line in Fig. 1.9.  What is the Y intercept for this line?  What is the equation for this line?
    1. Wikipedia on log-log graphs
  24. More questions on Fig. 1.9
  25. What is the difference between an isometric and an allometric relationship between physiological variables?
  26. Why is the surface area to volume ratio important for physiology?  What happens to surface area as volume of a cube or sphere increases?
  27. Explain the significance of the four terms in the equation Y = aMb.
  28. In the equation Y = aMb, what is occurring if b<1, b=1, and b>1.
  29. For values of b< or >1, what is the advantage of plotting variables on log scales for both X and Y?
  30. Why are there allometric changes in structures for different sized organisms?
  31. Why are there allometric changes in the proportions of the limb bones of a mouse and an elephant?
  32. When comparing length to mass with an allometric equation, what is the exponent for isometry?  Explain why.
  33. When comparing are to mass with an allometric equation, what is the exponent for isometry?  Explain why.
  34. When comparing volume to mass with an allometric equation, what is the exponent for isometry?  Explain why.
  35. Why is the relationship of the surface area and volume of different size cubes or spheres isometric, even though surface area to volume scales to the 2/3 power for length or radius? Compare the surface area, volume, and the ratio between the two of different sized cubes.
  36. Define, explain the importance to animal physiology, and give an example of the following.
    1. Acclimation
    2. Acclimatization
    3. Acute Response
    4. Adaptation
    5. Allometry
    6. Chronic response
    7. Evolutionary response
    8. Homeostasis
    9. Isometry
    10. Negative feedback control
    11. Phenotypic plasticity
    12. Positive feedback control
    13. Temperature (or other environmental parameter) conformity
    14. Temperature (or other environmental parameter) regulation

 

    Chapter 7 Energy Metabolism
    REVIEW QUESTIONS

Some of these questions have been taken other Animal Physiology pages.  All questions require answers that fully explain the conditions, causes, and results.

  1. Why do animals need energy?
  2. What is metabolic rate (MR)?
  3. How is direct calorimetry used for measuring the metabolic rate of an animal?  What are its advantages and disadvantages?
  4. The latent heat of melting is 80 cal/gram and 1 calorie = 4.2 Joules. If a 100 gram rat melts 300 grams of ice in 10 hours
    1. What is its total metabolic rate (in Joules/hour)? 
    2. What is its mass specific metabolic rate (in Joules/kg/hour)? 
  5. How is respirometry used for measuring the metabolic rate of an animal?  Why is it called indirect calorimetry?  What are its advantages and disadvantages?
  6. Why can the rate of oxygen consumption often be used to estimate the metabolic rate in many animals?  When is this estimate inaccurate?
  7. Describe how RQ (Respiratory Quotient or Respiratory Exchange Ratio) is calculated.
  8. What information can be learned by determining the RQ?
  9. If RQ =1 (or some other value), what conclusions can be drawn?
  10. Explain the trend in Basal MR (BMR) as a function of body mass.
  11. What is the mathematical relationship between total metabolic rate and mass specific metabolic rate? 
  12. If you weigh 70 kg and your total metabolic rate is 2000 kcal/day, what is your mass specific metabolic rate?
  13. If you weigh 70 kg and your mass specific metabolic rate is 20 kcal/kg/day, what is your total metabolic rate?
  14. If the formula to calculate total metabolic rate (in liters of Oxygen/hour) is
    1. MR = 0.676 * Mb0.75, what is the formula to calculate the  mass specific metabolic rate?
  15. Figure 7.6 compares the food requirements of a rodent and a rhino? 
    1. A 30 g mouse consumes 175 g of food/day.
      1. What is its total metabolic rate?
      2. What is its mass specific metabolic rate?
    2. A 1900 kg rhino consumes 650 kg of food/day.
      1. What is its total metabolic rate?
      2. What is its mass specific metabolic rate?
    3. How much food/day would a rhino have to consume if it had the same mass specific metabolic rate as the rodent?
  16. In Figure 7.7, the Y axis is metabolic rate in Joules/hr. The X axis is body mass in grams..
    1. What is the equation for the dashed line?
    2. Explain what the dashed line would indicate about the relationship between metabolic rate and body mass.
    3. The solid line shows the actual  relationship between metabolic rate and body mass.  Why is it different from the solid line?
    4. metabolic rate
  17. Figure 7.7 shows that total metabolic rate does not increase linearly with body mass.  What does this mean?
  18. Describe and explain what Fig. 7.8 tells us about the relationship between body mass and mass specific metabolic rate in mammals.
  19. How is Fig. 7.8 related to Fig. 7.10a?  Why is Fig. 7.8 parabolic and 7.10 linear?
  20. For Fig. 7.10a,  the Y axis is mass specific metabolic rate in mL O2/g//hr. The X axis is body mass in grams.
    1. Calculate the the slope?.  What does this indicate about the relationship between body mass and metabolic rate? 
    2. mr
  21. Heart size in mammals is directly proportional to body mass (Fig. 7.11).  How do mammals compensate for the allometrically increasing mass specific rate with decreased body mass?  How does this relate to the food requirements of large and small mammals (Figs. 7.6, 7.12)?
  22. Be able to calculate mass specific metabolic rates from a graph that shows total metabolic rates.
  23. Why do smaller mammals have shorter life spans than larger mammals?
  24. What are the ecological consequences of the relationship between metabolic rate and body mass in herbivorous mammals,
  25. According to Rubner's Law, total metabolic rate scales to body mass to the 2/3 power.  Why did physiologists think the slope was correct?
  26. What does figure 7.9 indicate about mass specific metabolic rate across the animal kingdom.  Why did this cause animal physiologists to question some of the original explanations about mass specific metabolic rate?
  27. mr
  28.  How does fractal geometry explain why the slope of the Kleiber equation is 0.75 (Fig. 7.13)?
  • Define, explain the importance to animal physiology, and give an example of the following
    1. Second Law of Thermodynamics
    2. Entropy
    3. Direct Calorimetry
    4. Respirometer
    5. Basal Metabolic Rate
    6. Standard Metabolic Rate
    7. Activity metabolic rate
    8. Metabolic scope
    9. Kleiber's Law
    10. Respiratory Exchange Ratio
    11. Rubner's Law
    12. Metabolic time

    _______________________

     

    The Y axis is MR (kcal/day)

    1. What is the total metabolic rate of the mouse?
    2. What is the total metabolic rate of the horse?
    3. What is the mass specific metabolic rate of the mouse?
    4. What is the mass specific metabolic rate of the horse?
    5. How many rabbits by weight = 1 horse?
    6. How many kcal/day of food will these rabbits will consume to maintain their metabolic rate?
    7. Although all these rabbits weigh the same as one horse, they will consume ____________ times more food (kcal/day) than one horse. (2 points)

     

    The following question is taken from Animal Physiology -- Biology 462, University of Washington. Metabolism II -- Body Size, Endothermy vs. Ectothermy, R. B.Huey

    Typical values for vertebrates, where MR is in ml O2/hour, W in grams. b = slope, a = Y intercept of exponential equation MR = a * Wb

    ______________________________________________________________________________

    Taxon                                        a          b      time (hr) for a 1 g animal to use 10 ml O2
    _____________________________________________________________________________

    Endotherms

    passerine bird (42ºC)                7.5       .72         1.3

    placental mammal(37ºC)           3.8       .75         2.6

    marsupial (35ºC)                       2.3       .75         ? calculate

                average =                      4.5       .74         2.2

    Ectotherms

    lizard (37ºC)                           .42       .82          23.8

    frog (ranid) (25ºC)                   .29       .75       ? calculate

    fish (25ºC)                              .20       .70       50

    beetles (22-25ºC)                   .23       .86       ? calculate

                average =                    0.4       .78       43.5

    ______________________________________________________________________________

    1. Exercise 1: Fill in the "?" values in the table using the allometric values given  (e.g., solve for t)
      1. If W=1, then MR = 10 ml O2 / hr = a*1b*t, 10 = a*1*t
    2. Exercise 2: calculate the times for a 100 g animal of each taxon to use 10 ml O2.
      1.  (If M=100, then MR = 10 ml O2 / hr = a*100b*t)

     

    1. What is the equation for this line? [MR = a * Wb, where MR is the metabolic rate in Kcal/day, and W is the body mass in kg]

     

    1. What is the equation for this line?
    2. What is the TOTAL metabolic rate of a mammal that weighs 1500 g.

     

    1. Reguarding Tusko
      1. If  a 2.6 kg cat receives a dose of 0.26 mg LSD, what is the dose per kg for the cat?
      2.  If Tusko weighs 2600 kg, what is the dosage based on weight alone using the information from the cat?
      3. If  a 70 kg human receives a dose of 0.20 mg LSD, what is the dose for a per kg for the human?
      4. Use the human dosage/kg to calculate the dosage for Tusko.
      5. Based on the cat mass specific metabolic rate (0.53 lO2/kg/h) and the elephant mass specific metabolic rate (0.09 lO2/kg/h), what should tusko's dosage have been?
    2. Another question from Animal Physiology -- Biology 462, University of Washington. Metabolism II -- Body Size, Endothermy vs. Ectothermy, Raymond B.Huey
      1. Researchers had found that a daily dose of 500 mg acrylamide (for life!) induces cancer in rats.
        1. The California Attorney General was alarmed by this finding and wanted to force warning labels on French fries and potato chips, because cooking of these starches produces acrylamide. However, a newspaper article discounted this as a problem because the author felt that (based on the rat data) a human would need to eat 35,000 mg of acrylamide per day to induce cancer. That’s about 180 pounds of French fries per day!
        2. The newspaper reporter’s estimate of 35,000 mg/day was obviously based on scaling by weight. If a rat weighs 1 kg, and a human weighs 70 kg, then 70 * 500 = 35,000 mg.
      2. Compute the daily safe dose if risk scales not with mass but with total metabolic rate  
        1. Metabolic rate for mammals:
        2.  MR = 3.8 W75
        3. Compute the total MR for the 1 kg rat and the 70 kg human
        4. How many times greater is the human's MR versus the rat?
        5. This suggests a safe daily dose of __?  (hint: your answer should be more than 500, but less than 35,000 mg/day)
      3. If instead of the total metabolic rate, what if the safe dose depended on clearance time from the body, where clearance time might (hypothetically) scale with the mass specific metabolic rate and not with body mass.
        1. Mass specific MR for mammals:
        2.  MR/W = 3.8 W-0.25
        3. Compute the total MR for the 1 kg rat and the 70 kg human
        4. How many times greater is the rat's MR/W versus the human?
        5. This suggests a safe daily dose  for humans of __? (hint: your answer should be less than 500 mg/day)
    3. What if dosage depends on both body mass and mass specific metabolic rate.
      1. First,  if the optimal dose for a 100 kg adult is 100 mg, what is the optimal dose for a 10 kg child based on body mass alone?
      2. If the total metabolic rate of a 10 kg child is half that of a 100 kg adult, what is the proper dose based on MR alone?
      3. If  the mass-specific metabolic rate (MR/W) of a 10 kg child is twice as high as that of a 100 kg adult, indicating the child would be metabolizing the drug twice as fast as the adult rendering it ineffective, what is the proper drug dosage for this child based on both weight and MR/W?

    Chapter 10 Thermal Relations
    REVIEW QUESTIONS

    Some of these questions have been taken from other Animal Physiology pages.  All questions require answers that fully explain the conditions, causes, and results.

    1. Fill in the six empty boxes in Fig. 10.1.
    2.  Fig 10.1
    3. Are ectotherms/poikilotherms 'cold-blooded'?
    4. Do ectotherms/poikilotherms have constant or variable body temperatures?
    5. What is the difference between a heterothermic endotherm and a homothermic endotherm?
    6. What is the difference between temperature and heat?
    7. Why are ecologists and other biologists concerned about the affects of global warming (Fig. 10.2, Box 10.1, Figs A,B,C,D)
    8. Discuss and characterize the four major avenues by which an animal exchanges heat with its environment (Fig. 10.3).
    9. Water at 10 degrees C feels colder than air at the same temperature. Why?
    10. Be able to calculate surface area to volume ratios for cubes and spheres.
    11. How does surface area change as volume changes?
    12. Why is surface area to volume important for thermal regulation?
    13. What is the relationship between conduction and convection in relation to heat loss?
    14. How do jackrabbits regulate and control heat loss (Fig. 10.5)?
    15. What do HWA Figs. 10.8a and b indicate about the regulation of body temperature of lizards?  Why is it important that both 10.8a and b are presented?
    16. What is a Q10? How is it calculated?  Why is it physiologically important?
    17. Given the Q10 and the metabolic rate at a particular temperature be able to construct a graph similar to HWA Fig. 10.10.
    18. Be able to calculate the Q10 from figures such as Figs. 10.9, 10.10, 10.11, 10.12.
    19. 10.9
    20. Does a given animal have a single Q10 for all physiological activities and across temperature ranges?   Why would it be advantageous to have a temperature sensitive Q10?
    21. What is being shown in HWA Fig. 10.11?  Why is temperature acclimation important to this species?
    22. compensation
    23. In Fig. 10.12,
      1. What is the acute response to falling temperature? What is the acclimation response?   Why is it termed partial compensation?
      2. Why do lizards acclimated at 33oC has a lower rate of oxygen consumption compared to a lizard acclimated at 16oC?
      3. What physiological changes enable the response shown in Fig 10.12? (Hint, see Fig. 10.14 for two examples.)
      4. What is the difference between the acute response to declining temperature by an ectotherm and the acclimation response  to declining temperature in an ectotherm?  (Fig. 10.12).
    24. What is the difference between an acclimation response and an adaptive response by fishes to different water temperatures (Fig.10.21)?
    25. What do Figs. 10.20 & 10.21 demonstrate about enzyme-substrate affinity in different species of fish that normally live at different water temperatures?
    26. How are extremely low temperatures physiologically detrimental to animals?
    27. What is the major difference in response to cold by ectotherms and endotherms?
    28. What are nucleating agents?  How do they function?
    29. What are cryoprotectants?  How do they function?
    30. What happens to cryoprotectants seasonally in animals exposed seasonally to freezing temperatures (Fig. 10.26)?
    31. What are the two functions of cryoprotectants to protect against cold temperatures?
    32. Nucleating agents can both increase freeze damage and decrease it. What are nucleating agents in general and how might they act to decrease freeze damage?
    33. Explain how some invertebrates and lower vertebrates survive freezing.
    34. Describe the cellular and extracellular processes that enable a frozen wood frog (Fig. 10.27) to survive freezing.
    35. What is the difference between freeze tolerance and freeze avoidance? Which of these two adaptations would an animal use if it needed to be active in cold weather?
    36. Would you expect an animal from an intertidal area to have a greater or lower thermal tolerance range (area) than a benthic animal?   Why?
    37. How do endotherms regulate their body temperature inside the thermal neutral zone?
    38. How do endotherms regulate their body temperature below the thermal neutral zone?
    39. How do endotherms regulate their body temperature above the thermal neutral zone?
    40. Explain Fig. 10.28 carefully.  What is Tlc (lower critical temperature)?  What happens to metabolic rate as ambient temperature drops below Tlc?
    41. In Fig. 10.28, why doesn't metabolic rate change when Ta goes from 38 to 8 degrees (or 8 to 38 degrees)?
    42. Why does the graph line of MR versus Tair in Fig. 10.29a intersect the X axis at Ta = Tb?
    43. What is the relationship between conductance and insulation?  Why?  Explain figure 10.29c.
    44. What mechanisms contribute to thermoregulation within the thermoneutral zone?
    45. What mechanisms contribute to thermoregulation at temperatures above the upper critical temperature? Why does the overall metabolic rate increase above the UCT?
    46. What mechanisms contribute to thermoregulation at temperatures below the lower critical temperature?
    47. What is regional heterothermy? Expplain what is occurring in Figs. 10.32, 10.33, & 10.34.
    48. Describe the roles of counter-current exchange systems in establishing regional heterothermy (Figs. 10.36, 10.38)
    49. Draw and label a picture showing how a countercurrent system in the limb of an arctic mammal works.  (Figs. 10.36, 10.38)
    50. Compare, contrast, and explain the responses to changing temperature of a sloth, a lemming, and a white fox (HWA Fig. 10.41).
    51. How do birds minimize heat loss?
    52. How does huddling behavior help male emperor penguins survive the long periods they must go without food while they incubate eggs?
    53. What is the main mechanism that marine mammals rely on to stay warm in cold water?
    54. What is a rete mirabile. How does it function?
    55. How is circulation in heat exchangers modified to retain heat?
    56. How is circulation in heat exchangers modified to dissipate heat?
    57. How does evaporation work as a cooling mechanism?  What are some of its costs?
    58. Why is using evaporative cooling a dangerous strategy for most desert animals?
    59. How does panting work as a cooling mechanism?  What are some of its costs?  How can costs be reduced?
    60. How do birds lower their body temperature?
    61. Explain and illustrate how nasal countercurrent systems work.
    62. Why is it important for the brain to remain cooler than an overheated body?  How is this done?
    63. How do gazelles keep their brains at a lower body temperature when they are active (be able to draw and explain Fig. 10.37)?
    64. Explain the mammalian physiological specialization to different climates shown in Fig. 10.41.  Explain the relationship between the width of the thermal neutral zone and conductance in tropical versus arctic mammals.
    65. Why do small animals hibernate?  What is the definition of hibernation?
    66. What are the major physiological changes that occur during hibernation?
    67. Explain what is illustrated in Figure Fig. 10.44  What is physiological significance of the distance between the homeothermic and hypothermia lines?
    68. Why do hummingbirds undergo daily torpor?  What physiological changes occur?
    69. Explain how the arrangement of arteries and veins contributes to maintaining constant body temperatures in poikilotherm animals.
    70. Explain how fish maintain body temperatures above ambient water temperatures.  (Fig. 10.45)
    71. Discuss 'endothermy' in large fish such as tuna.  How is it made possible?  Why it needed?  Use illustrations to elucidate your answer.  (Fig. 10.45)
    72. How do tuna manage to keep their power swimming muscles at an elevated temperature?  (Fig. 10.45)
    73. Sphinx moths require muscle temperatures = 35 degrees C for hovering flight.  They can never the less achieve hovering flight when ambient temperatures = 10 degrees C.  How do they manage this? (Fig. 10.48)

     

  • Define, explain the importance to thermal physiology, and give an example f the following
    1. Endothermy
    2. Ectothermy
    3. Poikilothermy
    4. Heterothermy
    5. Homeothermy
    6. Temperature
    7. Heat
    8. calorie
    9. Core body temperature
    10. Heat balance
    11. Conduction
    12. Convection
    13. Evaporation
    14. Radiation
    15. Vasoconstriction
    16. Vasodilation
    17. iBehavioral thermoregulation
    18. Q10
    19. Thermal compensation through acclimation
    20. Thermal compensation through adaptation
    21. Antarctic fish
    22. Nucleating agents
    23. Freeze avoidance species
    24. Freeze tolerant species
    25. Supercooling
    26. Cryoprotectant
    27. Antifreeze molecule
    28. Lethal temperature
  • Define, explain the importance to thermal physiology, and give an example of the following
    1. Homeothermy
    2. Thermal neutral zone
    3. Lower critical temperature
    4. Upper critical temperature
    5. Brown adipose tissue (Fig. 10.31)
    6. Conductance
    7. Countercurrent heat exchanger
    8. Gular flutter  (Fig. 10.30)
    9. Hibernation (Fig. 10.42)
    10. Huddling
    11. Non-shivering thermogenesis
    12. Shivering thermogenesis
    13. Panting
    14. Pyrogen
    15. Regional heterothermy
    16. Carotid rete mirabile
    17. Thermal Map
    18. Hibernation
    19. Daily torpor (Fig. 10.43)
    20. Estivation
    21. Swim muscle rete mirabile (Fig. 10.45)

    Chapter 12 Neurons
    REVIEW QUESTIONS

    1. How are the nervous system and endocrine systems similar? How do they differ?
    2. Describe a simple reflex circuit.
    3. Define: nerve, neuron, axon, and synapse.
    4. Be familiar with the generalized structure of a 'typical' neuron, as shown in fig. 12.2 or 12.4. Be able to label the parts and explain their function.
    5. 12.2
    6. What is the significance of the giant axon of the squid to neural research?
    7. What generates the resting potential in a nerve cell?
    8. What happens to the membrane potential of the squid axon when the axoplasm is removed? Explain why.
    9. What are the relative concentrations of Na+, Cl-, K+, and non-permeating anions inside and outside a neuron? (Fig. 12.12a)
    10. Why is the resting potential of a neuron about -70 mV?
    11. Be able to use a simplified version of the Goldman equation as discussed in lecture to calculate the membrane potential. The following example is given in the text and on the class webpage.
      1. Goldman
      2. [K] out = 20 mM
      3. [K] in = 400 mM
      4. [Na] out = 440 mM
      5. [Na] in = 44 mM
      6. PK=10 and PNa=1
      7. Given the equation, compute the membrane potential Vm
    12. What is the role of the Na+/K+ pump in neuron function? How does it work?
    13. What is the difference between pump (Na+/K+), ligand-gated (Na+ and K+) and leak channels (K+)?
    14. Explain what causes the balance of inflow and outflow of K+ ions across the cell membrane at equilibrium.
    15. Why are both a pump (Na+/K+) and leak channels (Na+ and K+) required to maintain the resting membrane potential?
    16. Explain what graded potentials are. How do they differ from action potentials?
    17. Define the terms polarize, depolarize, repolarize, and hyperpolarize in relation to membrane potential.
    18. How are voltage gated channels important to the propagation of an action potential?
    19. Draw a picture showing the change in voltage potential in the generation of a single action potential. Fully label the graph and the different parts of the action potential curve and the different parts of the action potential curve.
    20. Given an unlabeled version of a figure such as 12.14a, label the axes and the different parts of the action potential curve. Be able to explain what is causing the different membrane potentials.
    21. action potential
    22.  In Fig. 12. 14 or 12.15 label the resting, rising, falling, and recovery phases. Discuss what is going on the K leak channel, voltage gated Na channel and voltage gated K channels in each of the phases and discuss how this relates to the membrane potential at each of these four phases.
    23. Mark on the figure when the Na voltage gated channels are opened.. What does this result in?. Why?
    24. Mark on the above when the Na volatge gated channels are closed but activated and the K voltage gated channels are still open. What does this result in? Why?
    25. The Nernst equattion can be used to the equilibrium potential in millivolts for any particular ion.  For mammals, z = 1.
    26. Nernst
      1. The peak of the action potential is determined by the sodium equilibrium potential.  For mammalian muscle, Na+ (out) = 143 mM; Na+ (in) = 12 mM.  What is the maximum depolarization value?
      2. The trough of the action potential is determined by the potassium equilibrium potential.  For mammalian muscle, K+ (out) = 4 mM; K+ (in) = 155 mM.  What is the greatest hyperpolarization value?
    27. Be able to fully explain Fig. 12.15. Discuss what is going on the K leak channel, voltage gated Na channel and voltage gated K channel in the resting, rising, falling, and recovery phases and how this relates to the membrane potential at each of these four phases.
    28. In Fig 12.14 indicate when hen are the voltage gated Na channels closed. open. inactivated.
    29. Explain the rising and falling phases of the action potential in terms of: sodium and potassium ions, sodium and potassium channels, and the sodium/potassium pump.
    30. What causes polarization? Depolarization? Repolarization? Hyperpolarization?
    31. What meant by the statement that the action potential is an “all-or-none” phenomenon? Explain.
    32.  Explain why APs are called "all-or-none" electrical signals
    33. How does the local anesthetic novacaine affect the generation of an action potential? the general anaesthetic, ether?
    34. Draw a typical action potential on a graph of voltage vs. Time, label the axes, and draw a line to the points where significant changes are going on within the Na+ gate, K+ gate and changes in ion flows.
    35.  What stimulus causes the voltage-gated Na channels to open?
    36. What causes the relative refractory period?
    37. What causes the absolute refractory period?
    38. What effect does the absolute refractory period have on the transmission of action potentials?
    39. On a figure of an action potential such as the one below, label
      1. where the voltage-gated sodium channels are open.
      2. where the voltage-gated sodium channels are iinactivated.
      3. where the voltage-gated sodium channels are closed.
      4. the point where voltage-gated sodium channel first open.
      5. the point where voltage-gated sodium channel are all opened.
      6. the point where voltage-gated sodium channel are first closed.
      7. the point where voltage-gated potassium channel are all opened.
      8. the point where voltage-gated potassium channel are first fully closed. 
      9. where the sodium-potassium pump is most active doing its most important work
      10. the absolute refractory period
      11. the relative refractory period
    40. ap
    41. Be able to draw an action potential over time, and explain how different relative ion permeabilities affect the different voltage changes.
    42. Describe the changes that occur in the membrane and its voltage once threshold is achieved.
    43. What is occurring to the Na+ and K+ voltage gated channels during the rising and overshoot phase?
    44. What is occuring to the Na+ and K+ voltage gated channels during the falling phase?
    45. What is occuring to the K+ voltage gated channels during the undershoot phase?
    46. What is an absolute and relative refractory period and what’s responsible for each?
    47. What are the roles of the Na+ and K+ voltage gated channels in depolarization, repolarization, and hyperpolarization?
    48. When are the Na+ voltage gated channels open? closed? inactivated? What is the result of each state?
    49. How is the action potential propagated along the axon?
    50. Why do action potentials not reverse direction?
    51. What are the Na+ and K+ voltage gated channels doing behind the action potential, at the action potential, and ahead of the action potential on the axon? (Fig. 12.25)
    52. Explain the significance of the refractory periods in insuring that the action potential travels down the axon in only one direction.
    53. Explain the importance of voltage-gated Na+ channel inactivation (closing of the inactivation gate) for an AP and for the absolute refractory period.
    54. If a stimulus to threshold is applied to the middleof an axon, explain what happens.
    55. Explain how an action potential propagates along an axon without decrementing.
    56. What determines the speed of an action potential?
    57. What is the advantage of having large diameter axons? The disadvantage?
    58. How does myelination affect the propagation of an action potential?
    59. What is saltatory conduction? How does it work?
    60. What is multiple sclerosis? Describe its affect on nerve transmission.
    61. How is it possible that the velocity is greater in the mammalian axon of the same diameter as the lamprey axon? Explain with a labeled figure showing how it occurs
    62. For a given conduction velocity, be able to calculate the time it takes to travel a certain distance. From the time and the distance, calculate the conduction velocity.
    63. If the conduction velocity of a mammalian axon is 40 m/sec, how many seconds does it take to travel from your spinal cord to your leg (about 1 m)?
    64. For Fig. 12.26 graphing the relation between conduction velocity and axon diameter, be able to determine the velocity for a given size axon, the size of the axon for a given velocity, and calculate the equation for any of the lines as an exponential equation. Be able to use the equation for values that are not on the graph.
    65. 12.26
    66. Define and explain the importance to nervous system/neuron function of the following. Use diagrams as appropriate in your answers to help explain your written response
      1. Absolute refractory period
      2. Acetlycholine
      3. Acetylcholinesterase
      4. All or none response
      5. Axon
      6. Axon hillock
      7. Cell body
      8. Central Nervous System
      9. Chemical synapse
      10. Conduction with decrement
      11. Conduction without decrement
      12. Dendrite
      13. Depolarization
      14. Ether
      15. Excitable cell
      16. Gated ion channel
      17. Giant axon
      18. Glial cells
      19. Goldmann equation
      20. Graded potential
      21. Hyperpolarization
      22. leak channel
      23. Multiple sclerosis
      24. neuron
      25. neurotransmitter
      26. Nodes of Ranvier
      27. Novacaine
      28. Post synaptic potential
      29. Post synaptic receptor
      30. Relative refractory period
      31. Repolarization
      32. Resting membrane potential
      33. Saltatory conduction
      34. Schwann cell
      35. Signal integration
      36. Sodium Potassium pump
      37. Summation
      38. Synapse
      39. Synaptic cleft
      40. Synaptic vesicle
      41. Threshold potential
      42. Voltage gated channels
        1. Sodium voltage gated channel
        2. Potassium voltage gated channel
        3. Calcium voltage gated channel

     

    REVIEW QUESTIONS

    Chapter 13 SYNAPSES

    1. What is an electrical synapse?  How do they function?  Where do they occur in mammals?
    2. Explain how a signal is transmitted across a chemical synapse. Explain what happens in the presynaptic and postsynaptic cells.
    3. Compare and contrast electrical synapses with chemical synapses, including advantages and disadvantages for each.
    4. What is a neurotransmitter?
    5. What is the difference between an ionotropic receptor and a metabotropic receptor?
    6. For figure 13.6 a, b, c  
    7. chemical synapse
      1. Are the figures showing an ionotropic receptor or a metabotropic receptor? Explain
      2. In Fig. 13.6a label the ion-gated calcium channels. Explain how ion-gated calcium channels are involved in signal transmission at the synapse.
      3. How does the action potential cause a neuron to release neurotransmitters? Label and explain what is occurring in Fig. 13.6 a, b
      4. Label and explain what is occurring in Fig. 13.6 c
    8.   Explain and draw a diagram that showing what causes a  voltage sensitive calcium channel to become activated and then what happens following activation at a nerve terminus. 
    9. What occurs in the postsynaptic cell when a neurotransmitter binds to a metabotropic receptor? (Figs. 13.6d, 13.19)
    10. metabotropic
    11. Explain what is meant by the statement "Metabotropic receptors act via second messengers."
    12. What occurs in the postsynaptic cell when a neurotransmitter binds to an ionotropic receptor? Explain the roles of acetylcholine, acetycholinesterase, ligand gated channels, and Na in this process (Fig. 13.9).
    13. synapse
    14. Figure 13.9 shows a 'Summary of events in chemical synaptic transmission at the vertebrate neuromuscular junction.' Eight steps are shown from the depolarization of the axon terminal (1) to the re-synthesis of acetylcholine (8).  Explain what is occurring at each step (including the cause and the effect).
    15. What is the function of acetylcholinesterase? (Fig. 13.11)
    16. Why don't postsynaptic membranes continue to depolarize after the neurotransmitter binds to its receptor?
    17. Discuss what causes an excitatory postsynaptic potential.  How does this affect the postsynaptic cell?
    18. Discuss what causes an inhibitory postsynaptic potential.  How does this affect the postsynaptic cell?
    19. What  causes the postsynaptic membrane ligand gated receptors to produce an excitatory postsynaptic potential (EPSP).
    20. What  causes the postsynaptic membrane ligand gated receptors to produce an inhibitory postsynaptic potential (IPSP).
    21. Explain the steps involved in the summing of  graded responses to generate an action potential.
    22. What is the difference between temporal summation and spatial summation in the post synaptic cell?
    23. Explain why it is the receptor and not the neurotransmitter that determines whether the postsynaptic membrane produces an EPSP or an IPSP.
    24. Explain how temporal summation or spatial summation triggers a response in the postsynaptic cell.
    25. What is the difference between flaccid paralysis and spastic paralysis?
    26. How do curare, nicotine, and botulism affect the function of acetylcholine?
    27. What would happen if the enzyme Acetylcholenesterase were disabled in your body?
    28. How does nitric oxide affect smooth muscle?
    29. How does Viagara stimulate the postsynaptic cell in a metabotropic synapse?

     

    REVIEW QUESTIONS

    Chapter 14 Biological Clocks

     

  • What is an endogenous rhythm?
  • Explain what happens to human biological clocks when there are no external cues as shown in Figure 14.12.
  • Give some examples of processes that show circadian rhythms (Table 14.3).
  • Explain what is illustrated in figure 14.13 and why it demonstrates circadian rhythms in the chaffinch?  What is the cause of the difference between 14.13a and 14.13b?
  • Discuss the difference between a trained and untrained rhythm, as shown for the flying squirrel in Fig. 14.14.
  • What is a free-running endogenous rhythm?
  • What is a zeitgeber?
  • What is the role of the superchasmatic nuclei in maintaining circadian rhythms?
  • What is the role of the pineal gland in maintaining circadian rhythms?
  • Explain the cellular mechanisms of circadian timekeeping as shown in Fig 14.15a
  • How does the oscillation in clock and cycle protein production affect transcription of the per and cry genes?
  • What is the evidence that the superchiamatic nuclei are involved in maintaining circadian rhythms (see Fig. 14.16)?

     

    Chapter 20 Muscles
    REVIEW QUESTIONS

    1. Label and discuss the function of the following in Fig 20.1b
      1. muscle fiber
      2. sarcolemma
      3. sarcoplasmic reticulum
      4. T-tubule
      5. myofiber
      6. myofibril
    2. Why does skeletal muscle appear to be striated?
    3. What proteins are involved in generation of force by all muscles?  What is their function?
    4. Study and be sure you understand figure 20.1c and d.  What is a vertebrate skeletal (striated) muscle made up of?
    5. Describe the structure of a sarcomere.  Where are sarcomeres found? (Figs. 20.1d, 20.2)
    6. The figure shows a sarcomere of a striated muscle. The letters represent regions of different shading.
    7. sarcomere.
      1.  What causes the light shading of region I?
      2. What causes the shading of region A not including H?
      3. When a skeletal muscle contracts, which regions get shorter? Why?
      4. When a skeletal muscle contracts, which region get longer? Why?
    8. Describe the basic structure and shape of the thick filaments and the thin filaments.  See Figure 20.1e and f.
    9. What are the two binding sites on a myosin head (Fig. 20.4)? What is their function in producing a power stroke?
    10. Describe the interaction between actin, myosin, ADP, and ATP in causing a sarcomere to shorten  (Fig. 20.3).
    11. What causes the thin and thick filaments to slide past one another?  What molecule provides the energy that allows the myosin to swivel and pull on the thin filament to which it binds?
    12. Be able to explain each of the 6 stages shown in Figure 20.5, 'Molecular interactions that underlie muscle contraction.'  Be able to answer questions such as, but not limited to
      1. What happens when ATP binds to the myosin head?
      2. What happens when the ATP dissociates to ADP + Pi?
      3. What happens when the Pi is released from the myosin?
      4. What happens when the ADP is released from the myosin?
      5. muscle
    13. What two additional proteins other than actin make up thin myofilaments and how are these three proteins arranged in a thin myofilament (Fig. 20.6)?
    14. Explain the roles of Calcium, tropomyosin and troponin in the process of muscle contraction  (Fig. 20.6).
    15. Describe the contraction of a muscle fiber, from arrival of the neural action potential to fiber relaxation. Use illustrations to elucidate your answers  (Fig. 20.7).
    16. Explain how an action potential arriving at the presynaptic terminal of a motor neuron triggers contraction of a postsynaptic muscle fiber.
    17. How is an impulse conducted across a neuromuscular junction?
    18. Explain the roles of acetylcholine and ligand-gated Sodium channels in the process of muscle contraction.
    19. Explain the roles of acetylcholine, calcium, motor neurons, neuromuscular junction, sarcoplasmic reticulum, and T-tubules in the process of muscle contraction.
    20. Skeletal muscle excitation includes all the steps from when a motor neuron releases acetylcholine until the sarcomeres begin to contract.  Explain the steps of the excitation phase (an illustration can help with your answer).  Include the following structures/molecules in your answer: action potential, calcium ions, ligand gated channels, sarcolemma,, sarcoplasmic reticulum, , T-tubules, tropomyosin, troponin
    21. Explain how the muscle fiber action potential is spread to reach all of the fibrils within the fiber.
    22. How does an action potential of a neuron trigger the release of Calcium in the muscle cell?
    23. Discuss the roles of actio potentials, t-tubules, dihydropyridine receptors, and ryanodine receptors in the process triggering muscular contraction.
    24. How does muscle relax following contraction?
    25. Why doesn't a muscle continue to contract once the calcium is released?
    26. What occurs during the latent period of muscle contraction? The contraction period? The relaxation period? (Fig. 20.9)
    27. If a muscle contains 10,000 sarcomeres in a series (i.e., end-to-end along its length), and each sarcomere can shorten by 2.5 microns/s, how fast can the muscle shorten?
    28. Describe the summation process shown in figure 20.10.  What is occurring in each of the 5 episodes in the figure?
    29. summation
    30. Differentiate between muscle twitch, wave summation, unfused (incomplete) tetanus, and fused (complete) tetanus.
    31. Describe and explain what is shown in Figure 20.11.  When and why is muscle tension maximized 2.0-2.25 microns?  Why is it less at shorter and greater lengths?
    32.  Describe the basic differences between the three kinds of vertebrate twitch.
    33. What is the difference between slow twitch (slow oxidative) and fast twitch A (fast oxidative glycolytic) muscle fibers?
    34. What is the difference between fast twitch A  (fast oxidative glycolytic) and Fast twitch B (fast glycolytic) muscle fibers?
    35. How do motor units regulate the force of muscle contraction?
    36.  How is it possible for muscles to produce graded responses?
    37. How does smooth muscle differ from skeletal muscle?

    Define and explain the importance to muscle contraction of the following.  Use diagrams as appropriate in your answers to help explain your written response

    1. Acetylcholine
    2. Actin
    3. ADP
    4. ATP
    5. Antagonistic muscle groups
    6. Calcium
    7. Cardiac muscle
    8. Creatine phosphate
    9. Cross-bridge
    10. Cross-bridge cycling
    11. Depolarization
    12. Isometric contraction
    13. Isotonic contraction
    14. Ligand-gated channel protein
    15. Muscle fiber
    16. Muscle fibril
    17. Myosin
    18. Oxygen debt
    19. Rigor mortis
    20. Sarcolemma
    21. Sarcomere
    22. Sarcoplasmic reticulum
    23. Skeletal muscle
    24. Sliding filament model
    25. Smooth muscle
    26. Summation
    27. Tetanus
    28. Transverse tubule
    29. Troponin
    30. Tropomyosin
    31. Twitch

     

    Chapter 22 RESPIRATION 1
    REVIEW QUESTIONS

     Some of these questions have been taken from other Animal Physiology pages. All questions require answers that fully explain the conditions, causes, and results.

    1. What are the functions of respiration?
    2. What is the difference between organismal respiration and cellular respiration?
    3. What are the percentages of oxygen, nitrogen, and carbon dioxide in dry air?
    4. What is the percentage of water vapor in the atmosphere?
    5. At 5,000 meters, the total barometric pressure is 380 mm Hg. What is the partial pressure of  N2?  Of O2?
    6. A gas mixture contains 0.2 mol of N2, 0.4 mol of O2, and 0.1 mol of CO2. For this mixture, what is the percent of each of the three gases?  If the mixture is at STP, what is the partial pressure (in mm) of each gas
    7. How does the solubility of oxygen in water compare with the solubility of carbon dioxide in water?
    8. Henry's Law states that the quantity of a gas that will dissolve in a liquid is proportional to the partial pressure of the gas and its solubility coefficient (its physical or chemical attraction for water), at a given temperature.
      1. Henry's Law: The volume of a gas (Vx) dissolved in a liter of water is Vx = (pX)*(SC) where pX is the partial pressure in atmospheres and SC is the solubility coefficient
      2. At one atmosphere and 37 degrees Celsius, the solubility coefficient for oxygen is 0.024 ml O2/ml H2O. How much oxygen can dissolve in a liter of water at 37 degrees Celsius if the partial pressure of oxygen is 85 mm Hg
      3. At one atmosphere and 20 degrees Celsius, the solubility coefficient for Carbon dioxide is 0.88 ml CO2/ml H2O at one atmospheree. How much CO2 can dissolve in a liter of water at 20 degrees Celsius if the partial pressure of CO2 is 38 mm Hg?
    9. What factors are responsible for rates of diffusion from gas to water? Explain why carbon dioxide will diffuse more rapidly than oxygen from air to water, if both are at the same partial pressure.
    10. How does temperature affect gas solubility?  What effects might this have on organisms?
    11. How does salinity affect gas solubility? What effects might this have on organisms?
    12. How does the difference in diffusion rate of a gas in air versus that of a gas in water affect the structure of respiratory organs (i.e., lungs versus gills)?
    13. Many air-breathing aquatic insects have a "diffusion lung" (Figure 22.3). Explain why an insect that takes down a bubble of normal air survive much longer than an insect that takes down a bubble of pure oxygen. In both cases the water is in equilibrium with the atmosphere above it.  Explain what happens if it takes a bubble of normal air down into water that lacks oxygen.
    14. Explain figure 22.5 (turtle egg incubation).  What does the graph show happened after day 50?  Why?  What does the graph show happened on day 60? How did this affect the eggs?
    15. Box 22.1:  Why is the larval anchovy able to survive without gills or circulatory system?
    16. Box 22.1:  What is the relationship between rates of diffusion and allometric change as the anchovy matures?
    17. Why do larger animals need circulatory systems, while smaller animals do not?
    18. Box 22.2:  Many subterranean mammals such as moles have low metabolic rates to cope with the low oxygen availability in their tunnels.  How are prairie dogs able to obtain enough oxygen to sustain high metabolic rates in their burrows?
    19. Why do larger animals need to supplement diffusion with convective flow to meet their gas exchange needs?
    20. What is the difference between external respiration and internal respiration?  Discuss the roles of convection and diffusion in each. (see Figure 22.7)
    21. Why is the movement from the lungs to the mitochondria an example of an oxygen cascade? (see Fig. 22.8)
    22. Explain what figure 22.8b shows with regard to the movement of oxygen from the air to the mitochondria.
    23. What are some of the advantages of obtaining oxygen from air versus water?  What is the main disadvantage?
    24. Define, explain the importance to respiratory physiology, and give an example of the following
      1. Dalton's Law
      2. Partial pressure of atmospheric gases
      3. Organismal respiration
      4. Cellular respiration
      5. External respiration
      6. Internal respiration
      7. Solubility coefficient
      8. Solubility of carbon dioxide
      9. Solubility of oxygen
      10. Diffusion
      11. Bulk flow
      12. Unidirectional flow
      13. Tidal flow
      14. Oxygen cascade

     

    Chapter 23 - RESPIRATION 2
    REVIEW QUESTIONS

     Some of these questions have been taken other Animal Physiology pages.  All questions require answers that fully explain the conditions, causes, and results.

    1. Discuss the relationship between surface area and volume as it relates to diffusion.
    2. Why can small organisms rely solely on diffusion for gas exchange?
    3. Why do small animals that rely solely on diffusion for respiration tend to be flattened in shape?
    4. What types of organisms tend to rely on cutaneous gas exchange?
    5. Compare air and water as media for respiratory gas exchange.
    6. How do viscosity and density affect the cost of ventilation in water breathing versus air breathing animals?
    7. List and explain the three primary properties of air and water that make respiration in water more difficult than respiration in air.
    8. Why do most terrestrial organisms use bi-directional flow for respiration, while most aquatic organisms use unidirectional flow?
    9. How do the physical properties of air and water dictate the form of the structures animals use for gas exchange?
    10. Why is it that organisms that use water as their respiratory medium are almost never 'warm-blooded?'
    11. Compare and contrast cocurrent, countercurrent, and crosscurrent arrangements of flow between the respiratory medium and blood.
    12. Draw a figure (similar to 23.4a) that shows how cocurrent (parallel) exchange occurs.  Do the same for countercurrent flow (23.4b).  Explain the different results.
    13. What does figure 23.7a indicate about respiratory surfaces within a group of vertebrates?  Why?
    14. What does figure 23.7a indicate about respiratory surfaces between groups of vertebrates?  Why? 
    15. What is the general relationship between respiratory surface area and metabolic rate?
    16. What is the most surprising group of vertebrates plotted in figure 23.7a?  Explain.
    17. Describe the gills of fish and the mechanisms by which water is pumped across the respiratory exchange surface of fish. What is the arrangement between blood flow and the flow of water?
    18. Explain the structural features and mechanisms of fish gills that maximize the extraction of oxygen from water (see fig. 23.10)
    19. Explain how the fact that blood and water flow in opposite directions in the gill of a fish enhances the exchange of oxygen between the water and the blood.
    20. Why is it important that water be moved over the surface of a gill?
    21. What are the general similarities and differences between the structure of gills and lungs?
    22. Why is it that lungs do not make good gills and gills do not make good lungs?
    23. Describe and discuss the breathing cycle in teleost (bony) fish.  (Figure 23.11)
    24. Compare and contrast ram and opercular ventilation in fish.
    25. Compare and contrast the difficulties experienced by aquatic and terrestrial animals in obtaining oxygen. Give an example of the solutions to these problems employed by a terrestrial and aquatic animal.
    26. How do viscosity and density affect the cost of ventilation in water breathing versus air breathing animals?
    27. What is a positive (buccal force) pressure pumps? Which terrestrial vertebrates use it?  Explain briefly it functions.
    28. Explain why in Figure 23.15 (the development of external respiration in the bullfrog) the carbon dioxide excretion curves for skin and lungs differ from the oxygen uptake curves for skin and lungs.
    29. How does the structure of the mammalian lung differ from the reptile lung?  Explain why.
    30. Discuss the mechanics of inhalation and expiration in mammals.
    31. Define the following: Tidal volume, Inspiratory reserve volume, Expiratory reserve volume, Residual volume, Dead Space.
    32. If a mammal's tidal volume is 2 L, its tracheal volume is 80 mL, its anatomical dead space volume is 350 mL, and its breathing frequency is 9 breaths/minute, what is the rate of gas exchange in the alveoli?
    33. Describe how mammals ventilate their lungs (inhalation and exhalation).
    34. Describe the anatomy of the bird respiratory system and the bird lung
    35. What are the unique adaptations of the bird respiratory system that make it work so efficiently?  Explain. 
    36. How is it that the PO2 in the lung of a bird is greater than the PO2 in the lung of a mammal (at same elevation)? (make sure to explain your answer)
    37. Compare and contrast parabronchii and alveoli.
    38. Describe how air is transported through the lungs of a typical bird (Fig. 23.22).  Explain what happens with each inspiration and expiration to move air through the respiratory system.
    39. What advantages do birds seem to gain over mammals by the design of their respiratory system?
    40. Describe and illustrate the tracheal system of insects.
    41. What are tracheae?  What are spiracles?
    42. Explain the basic design of the gas exchange system in insects.  Is the circulatory system involved?  Why or why not?
    43. Outline the differences among the three most sophisticated lungs found in modern animals: the mammalian lung, the avian lung, and the insect tracheal system.
    44. What are the physiological problems if mammals attempted to breathe water (why do we drown and fish don't?)
    45. Define, explain the importance to respiratory physiology, and give an example of the following
      1. Surface area/Volume
      2. Ventilation
      3. Gill
      4. Lung
      5. Unidirectional flow
      6. Tidal flow
      7. Cocurrent flow
      8. Countercurrent flow
      9. Crosscurrent flow
      10. Countercurrent blood flow in fish gills
      11. Buccal pumping
      12. Opercular pumping
      13. Ram ventilation
      14. Cutaneous respiration
      15. Alveoli
      16. Diaphragm
      17. Dead space
      18. Tidal ventilation
      19. Tidal volume
      20. Tracheal system

    Chapter 24 GAS TRANSPORT

    REVIEW QUESTIONS

    1. One could say that a respiratory pigment with relatively low O2 affinity is potentially disadvantageous for loading, but advantageous for unloading. Explain both parts of this statement.
    2. Outline the ways in which mammalian hemoglobin simultaneously plays important roles in O2 transport, CO2 transport, and control of blood pH..
    3. The hemoglobin in mammalian blood is usually thought of simply increasing the amount of oxygen that can be carried by each liter of blood. In a lecture on hemoglobin, a respiratory physiologist made the following statement: "The presence of hemoglobin in the blood also makes possible the rapid uptake of oxygen by the blood as it flows through the lungs." Explain the lecturer's point.
    4. What are the two principal reasons for enclosing oxygen carrying proteins in blood cells?
    5. What is the functional significance of the typical sigmoid shape (Fig. 24.4) of the hemoglobin-oxygen dissociation curve? What is the advantage of the shape of the curve at oxygen partial pressures > 80 mm Hg; < 40 mm Hg.
    6. Using Fig 24.5, show how much more oxygen is released to tissues doing exercise versus tissues at rest.
    7. For Fig. 24.6, how much of a drop in O2 partial pressure is required to cause unloading of 5 vol % O2 if the initial concentration is 20 ml O2 /100 ml? 10 ml O2 /100 ml? Show how you calculated this.
    8. What is the significance of Figure 24.7? Why does the curve for myoglobin have a hyperbolic shape and the curve for hemoglobin a sigmoid shape? Why is the curve for myoglobin to the left of the curve for hemoglobin? What is the physiological significance of this for oxygen transport?
    9. Discuss the interaction between hemoglobin and myoglobin. Illustrate your answer with a graph (e.g., Fig 24.7) showing oxygen dissociation. Use actual numbers from the graph to show how it works.
    10. What is P50, and how is it related to the oxygen affinity of a respiratory pigment?
    11. Draw a hemoglobin-oxygen dissociation curve. What label should be given along the X-axis; the Y-axis? Circle the region of the graph that would be representative of the conditions in a mammalian alveolus of a lung; in a tissue capillary bed. What is the P50 for your graph?
    12. From a single oxygen-hemoglobin (i.e., no Bohr effect) dissociation curve, be able to determine and/or explain what the saturation will be for a given oxygen pressure; the oxygen pressure for a given saturation; the P50; the oxygen pressure and saturation in the respiratory organs; the oxygen pressure and saturation in the deep tissues; the change in oxygen pressure and saturation going from the respiratory organs to the deep tissues; and the change in oxygen pressure and saturation going from deep tissues to the respiratory organs.
    13. What is the Bohr Effect?
    14. Explain why higher temperatures tend to shift the Hb-O2 dissociation curve to the right.
    15. How does blood pH influence the Hb-O2 dissociation curve?
    16. Draw a single oxygen-hemoglobin (i.e., no Bohr effect) dissociation curve for a mammal with correctly labeled X and Y axes (e.g., a figure similar to Fig. 24.5). Blood leaving the lungs carries 20 ml O2 / 100 ml. From this curve, calculate the amount of oxygen that 100 ml of blood will unload to the respiring tissue. Show your work or no credit. Now do same for a graph showing the Bohr Effect (i.e., with two oxygen dissociation curves, (Fig. 24.10).
    17. Fully explain a figure showing the Bohr Effect (e.g., Fig. 24.10). Include information about what each of the two curves represent, what causes them to differ from each other, what is the advantage of each, and give an example of where each of the two is operating. Discuss an actual example with approximate real values of saturation %'s and oxygen pressures to demonstrate the adaptive advantage of this system.
    18. Examine and be sure you understand the graph Figure 24.10. Explain in words what is shown on the y-axis. What is shown on the x-axis? Discuss what each of the two curves represent, what causes them to differ from each other, what is the advantage of each, and give an example of where each of the two is operating. Discuss an actual example with approximate real values of saturation %'s and oxygen pressures to demonstrate the adaptive advantage of this system.
    19. Figs. 24.11 shows hemoglobin saturation curves for pH and CO2  partial pressures.  What causes these different  pH and CO2  values.  What is the advantage of the curves shifting to the left or right (see ig. 24.12)?
    20. Figs. 24.14 shows hemoglobin saturation curves for various temperatures. What is the advantage of the curves shifting to the left or right ? Would you expect to see all of these curves in a mammal?
    21. How does DPG affect the P50 of the blood (e.g. Fig.24.15 and 24.16)? What is the biochemical mechanism?
    22. How and why do humans at high elevations change their DPG levels?
    23. How and why do humans with anemia change their DPG levels?
    24. How and why do pregnant women change their DPG levels?
    25. What is the difference between adult and fetal hemoglobin?  Why is this advantageous?
    26. Fig. 24.20 shows what happens to the hemoglobin when water fleas are transferred to low O2 water.  Explain what kind of physiological changes (acute, chronic, and/or evolutionary) have occurred?  What physiological advantages do these changes cause?
    27. Discuss how and where carbon dioxide is transported in the blood.
    28. What are the chemical reactions that allow increased ability of the blood to transport higher amounts of carbon dioxide at higher partial pressures (Fig 24.21a)?
    29. Explain what is being shown in Figure 24.22a, i.e. the Haldane Effect.
    30. Explain Fig. 24.22b. What is the physiological significance of the Haldane Effect for humans who are exercising?
    31. What is the role of carbonic anhydrase in the deep tissues? In the lungs?
    32. Why is the enzyme carbonic anhydrase so critical for respiratory exchange in the circulatory system?
    33. What is the role of Cl- in CO2 transport in the tissues?  In the lungs?
    34. Define, explain the importance to respiratory physiology, and give an example of the following
      1. Respiratory pigment
      2. Hemocyanin
      3. Hemoglobin
      4. Erythrocyte
      5. Cooperativity
      6. P50
      7. Bohr Effect
      8. DPG (bisphosphoglycerate)
      9. erythropoietin
      10. Haldane effect
      11. Carbonic anhydrase

    CHAPTER 25 Circulation
    REVIEW QUESTIONS

    1.  After reading the chapter complete this homework assignment.
    2. What functions does the circulatory system perform?
    3. Know the path of circulation from the veins through the heart to the arteries.  Be able to label all the features shown in Fig. 25.1.
    4. What is occurring during systole?  During diastole? 
    5. How and why does ventricular pressure differ on the left and right sides of the heart?
    6. Explain what is occurring during the five phases of the heart cycle shown in Figure 25.2.
      1. Atriole systole
      2. Isovolumetric contraction
      3. Ventricular ejection
      4. Isovolumetric relaxation
      5. Ventricular filling
    7. How do atriole systole and ventricular relaxation add to the end diastolic volume?  Which is more important?
    8. At what stage do the atrio-ventricular valves close?  What causes this?
    9. At what stage do the atrio-ventricular valves open?  What causes this?
    10. At what stage do the pulmonary and aortic valves close?  What causes this?
    11. At what stage do the pulmonary and aortic valves open?  What causes this?
    12. Why isn't blood ejected during isovolumetric contraction?
    13. You should know that Cardiac output = (Heart Rate)*(Stroke Volume)
      1. If a normal cardiac output is 6 liters/minute (when the person is at rest), use your resting heart rate to find out the stroke volume.  
    14. From the blood capacity,beat volume, and pulse rate, be able to determine the amount of oxygen being transported by the circulatory system.  For example, use the capacity = 20 ml O2 / 100 ml blood, pulse rate = 60 beats per minute, and the stroke volume = 70 ml
    15. What causes the heart sounds heard with a stethoscope?
    16. What happens when heart muscles depolarize?  Repolarize?
    17. How is heartbeat regulated in mammals?
    18. What is the pacemaker? How does it control heart rate?
    19. Why to the ventricles contract after the atria?
    20. Briefly discuss the processes occurring during the wave of depolarization of the contraction cycle of the heart (Fig. 25.4b).
    21. Explain what is shown in the electrocardiogram of a normal human heart (Fig. 25.6).
    22. What does the P wave signify? The QRS complex? The T wave?
    23. What is the Frank-Starling Law of the heart?  What is its significance?
    24. How do positional effects affect blood pressure (Figure 25.7)?
    25. Blood pressure changes +/- 0.76 mmHg pressure for each cm of elevation or depression.
      1. How long would your neck have to be before your brain would not receive any blood if systolic pressure = 100 mm Hg? 
      2. If your feet are 1.5 m below your heart and if systolic pressure = 120 mm Hg, what is the maximum blood pressure in your toes?
    26. Discuss and explain blood pressure at your feet, heart, and head when you are standing up and when you are lying down.
    27. Compare and contrast blood pressure in a human and a giraffe.
    28. What animal phyla lack circulatory systems?  How do they respire?
    29. Compare and contrast an open and closed circulatory system.
    30. Compare and contrast arteries, veins, and capillaries.
    31. Illustrate and describe the circulatory system of a typical bird or mammal (Fig. 25.10).
    32. Illustrate and describe the general path of flow of blood through the circulatory system of a mammal.
    33. How does the heart of a bird or a mammal differ from that of a typical reptile?  What are the advantages of this arrangement?
    34. How does cross sectional area affect flow rate?
    35. Discuss and explain the changes in cross-sectional area from the arteries to the capillaries to the veins (Figure 25.12a).
    36. Why does blood pressure decrease from the arteries to the capillaries?  Explain Figure 25.12b.
    37. Discuss and illustrate what happens as blood flows through capillaries (Fig. 25.13).
    38. Explain the roles of hydrostatic pressure and osmomotic pressure in the capillaries (Fig. 25.13).
    39. What happens to hydrostatic pressure as blood flows through the capillaries.  What cause the changes?
    40. What happens to osmotic pressure as blood flows through the capillaries.  What cause the changes?
    41. What happens to excess fluid that leaves the capillaries and remains in the interstitial fluids?
    42. Getting blood back to the heart
      1. What is the blood pressure in the venous system?  What causes this? How does it change from the capillaries to the venae cava?
      2. What structures are present in veins that are absent in arteries?
      3. There are two mechanisms that utilize these structure to return blood to the heart. What are the two mechanisms and how do they work?
    43. How does the circulatory system of cephalopods differ from that of other mollusks?  Why?
    44. Illustrate and describe the anatomical arrangement of the heart of a teleost fish or shark (e.g., Fig. 25.14).
    45. Illustrate and describe the circulatory system of a teleost fish (e.g., Fig. 25.14).  Discuss the oxygen and blood pressure changes that occur in the circuit.  How is blood pumped to complete the circuit?
    46. Describe the basic anatomy and pattern of blood flow of the amphibian heart.  How does it differ from the fish heart?
    47. Does deoxygenated and oxygenated blood mix together in the undivided ventricle of amphibians?  Why?
    48. Compare and contrast a typical reptilian heart and the heart of a mammal (or bird).  Explain the significance of the differences.

    Define, explain the importance to the physiology of circulation, and give an example of the following

    1. Diffusion
    2. Systole
    3. Diastole
    4. Cardiac cycle
    5. Isovolumetric contraction
    6. Ventricular ejection
    7. Cardiac output
    8. Stroke volume
    9. Heart murmur
    10. Myogenic
    11. Sinoatrial node
    12. Pacemaker
    13. Atrioventricular node
    14. Electrocardiogram
    15. Starling's Law of the Heart
    16. Interstitial fluid
    17. Blood
    18. Lymph
    19. Closed circulatory system.
    20. Open circulatory system.
    21. Artery
    22. Vein
    23. Capillary
    24. Pulmonary circulation
    25. Systemic circulation
    26. Colloidal osmotic pressure of the capillaries
    27. Hydrostatic pressure of the capillaries
    28. Lymphatic system
    29. Erythrocyte

    CHAPTER 26 Diving Mammals
    REVIEW QUESTIONS

    1. What do Figures 26.2 and 26.3 indicate about the durations and depths of dives by Weddell seals?  Why is this physiologically significant?
    2. Which tissues need the most energy during diving?
    3. Which tissues need the most O2 ?
    4. Compare the blood oxygen stores of terrestrial and marine mammals.  How do they differ in carrying capacity?   Blood volume?
    5. What causes the blood of deep diving mammals to have a higher carrying capacity?
    6. Why does a greater blood volume increase oxygen stores?
    7. Compare and discuss the reasons for the different total as well as the individual lung, blood, and myoglobin oxygen stores of humans, shallow diving mammals, and deep diving mammals.  (see Figure 26.7)
    8. How is oxygen supply maximized in diving mammals?   Where is it stored?
    9. Compare oxygen storage in a marine mammal and a human.  
    10. Outline the pros and cons of carrying lots of air during a dive.
    11. What are the two main advantages for many marine mammals to compress their lungs when they dive (Fig. 26.6).
    12. Why do deep diving marine mammals have relatively small lungs?
    13. The graph below compares lung mass in shallow diving and deep diving whales (Piscitelli et al., 2010, Journal Morphology, 271: 654-673.) Which line is which? Why? Calculate the slope of both lines. Discuss the significance of each slope.
    14. How does the circulatory system respond to extended dives by whales and seals?
    15. How does the pattern of circulation pattern in a marine mammal during a deep dive?  Why?
    16. How can the muscles of marine mammals function if there is no oxygen available for them to contract?
    17. How important is myoglobin storage of oxygen to shallow diving mammals?
    18. How important is myoglobin storage of oxygen to deep diving mammals?
    19. Why (cause and function) do the lungs collapse during a deep dive?
    20. Why is it important to reduce the heart rate during a dive?
    21. What happens to the heart rate of some fish when they jump out of the water? (Box 26.1)  Why is this advantageous?
    22. What does Figure 26.8 show about circulatory patterns in a seal when it undergoes forced or prolonged submergence?
    23. What is produced by anaerobic metabolism in animals?  What potential problems does this cause?  How is this minimized?
    24. Discuss oxygen levels in the blood and muscles during the course of a deep dive (Fig. 26.11a).  What causes the difference between the two? What is the physiological advantage of this difference?
    25. Discuss lactic acid levels in the blood and muscles during the course of a deep dive (Fig. 26.11b). What causes the difference between the two?  What is the physiological advantage of this difference?
    26. Discuss what is happening to lactic acid levels in the blood following a deep dive (Fig. 26.12).  What causes the initial difference?  What causes the two to converge?
    27. Explain what Fig. 26.14 shows about Weddell seals whose dives last less than about 20 minutes.  More than 20 minutes?
    28. Based on the study of O2 needs and stores, the aerobic dive limit of young Weddell seals weighing 140 kg is calculated to be 10 minutes, whereas that for a fully grown 400-kg Weddell seal is calculated to be about 20 minutes.  Why might small individuals in general be expected to have shorter aerobic dive limits than large individuals?
    29. How do Weddel seals minimize lactic acid production during extended dives (Fig. 26.15)
    30. What is decompression sickness (the "bends" ?)
    31. Why is only nitrogen and not carbon dioxide or oxygen that divers have to worry about when breathing compressed air?
    32. Why do deep divers use low oxygen, high helium mixtures of air?
    33. Why do humans get the bends and how does the Weddell Seal avoid the problem?
    34. Why aren't deep diving marine mammals affected by nitrogen narcosis?

    Define, explain the importance to the physiology of diving mammals, and give an example of the following

    1. Hypoxia
    2. Carrying capacity
    3. Total blood stores of oxygen
    4. myoglobin
    5. Diving response
    6. Diving bradycardia
    7. Peripheral vasoconstriction
    8. Oxygen debt
    9. Aerobic dive limit
    10. Decompression sickness or the �bends�
    11. Nitrogen narcosis
    12. Oxygen toxicity

    CHAPTER 27: OSMOREGULATION and EXCRETION
    REVIEW QUESTIONS

     

    1. What is the difference between interstitial  and intracellular fluid?  Why are they usually different?
    2. How are ionoregulation and osmoregulation similar?
    3. What is the difference between ionoregulation and osmoregulation?
    4. What are the benefits of ionoregulation and osmoregulation?
    5. What are the costs of ionoregulation and osmoregulation?
    6. Discuss what is being shown in Figs 27.3a and 27.3b in regard to osmoregulation and osmoconformity.
    7. In figure 27.3c, how are the green crab, mussel, and shrimp responding to changes in salinity.
    8. Why are there no freshwater osmoconformers?
    9. Compare and contrast the advantages and disadvantages of being an osmoconformer versus an osmoregulator.
    10. What are the three sources of water for animals?
    11. What is the disadvantage of drinking salty water?
    12. How do kangaroo rats survive without having to drink water?

    Define, explain the importance to animal physiology, and give an example of the following

    1. Osmoregulation
    2. Ionoregulation
    3. Excretion
    4. Isosmotic animal
    5. Hyperosmotic animal
    6. Hyposmotic
    7. Drinking water
    8. Dietary water
    9. Metabolic water

     

     Chapter 28 Water and Salt Physiology
    REVIEW QUESTIONS 

    1. Fig 28.1 shows water-salt relations in a freshwater animal.  Be able to label and discuss the major sources of movement of salts and water in and out of the organism and the mechanisms (diffusion, etc.) responsible.
    2. Fig 28.8a shows water-salt relations in a freshwater bony fish.  Be able to label and discuss the major sources of movement of salts and water in and out of the organism and the mechanisms (diffusion, etc.) responsible.
    3. Fig 28.8b shows water-salt relations in a marine bony fish.  Be able to label and discuss the major sources of movement of salts and water in and out of the organism and the mechanisms (diffusion, etc.) responsible. .
    4. Fig 28.10 shows wate-salt relations in a marine shark.  Be able to label and discuss the major sources of movement of salts and water in and out of the organism and the mechanisms (diffusion, etc.) responsible.
    5. What are the main osmotic and ionic challenges of freshwater teleosts (advanced bony fish) and how are these challenges met?
    6. What is the role of the integument in osmoregulation?
    7. What osmoregulatory problems do most marine vertebrates face?
    8. What are the main osmotic and ionic challenges of marine teleosts and how are these challenges met?
    9. How do hagfish osmoregulate?
    10. Discuss osmoregulation in the life cycle of sea lampreys.
    11. How do sharks (elasmobranchs) avoid water loss in salt water?
    12. How do marine sharks (elasmobranchs) regulate water and salt?
    13. Explain how Latimeria (the coelacanth) and marine elasmobranchs solve the osmotic problem of a vertebrate in sea water and why their bodies are slightly hyperosmotic
    14. Describe osmoregulation in marine elasmobranchs. How are urea and TMAO important to this process?
    15. Review the strategies for salt and water balance in aquatic animals that live in-between fresh water and the marine environment. What is a hyper-isosmotic regulator; a hyper-hyposmotic regulator?
    16. Why is a teleost fish in the ocean like a desert animal?
    17. Explain osmotic and ion (salt) regulation in marine and fresh water teleosts.
    18. Explain how the salmon is able to osmotically move between fresh water and sea water.
    19. Explain osmotic and ion (salt) regulation in fresh-water amphibians.
    20. Compare and contrast the osmoregulatory strategies used by, marine invertebrates, marine teleosts and freshwater teleosts. For each you must mention the relative osmolarity of their body fluids to that of the environment in which they live.
    21. Cite the greatest advantage and disadvantage of terrestrial life.
    22. Why do amphibians face greater osmotic regulation problems than other terrestrial vertebrates?  How do some frogs and toads minimize this problem?
    23. List the various ways by which water is gained or lost in terrestrial animals.
    24. How do kangaroo rats maintain water balance?  How are they able to survive in hot dry deserts?
    25. Identify how marine reptiles and birds regulate their salt balance.

    Define, explain the importance to animal physiology, and give an example of the following

    1. hyperosmotic regulator
    2. hyposmotic regulator
    3. Chloride cells
    4. Salt glands
    5. Rectal gland
    6. TMAO
    7. urea
    8. Anadromous
    9. Catadromous
    10. Stenohaline
    11. Euryhaline

    Chapter 29 Excretion
    REVIEW QUESTIONS

    1. What are the six main functions of the kidney in maintaining homeostasis?
    2. Draw and label a mammalian nephron. For each division you label, indicate what goes on there in the formation of urine.
    3. Describe the function of Bowman's capsule, proximal convoluted tubule, distal convoluted tubule, loop of Henle, and the collecting duct of a nephron.
    4. What is the advantage of ultrafiltration?  How does it work?
    5. What is 'primary urine', and how does it differ from urine that is eliminated from the body.
    6. How is the pH of the blood regulated by nephrons?
    7. The two main mechanisms in urine formation are ultrafiltration and active pumping. Describe what is meant by each term, and how each contributes to urine formation. What are the main factors that influence the functioning of each mechanism?
    8. How is the osmotic gradient in the kidney produced?
    9. How is the osmotic gradient of the kidney used to produce hyperosmotic urine.
    10. Explain how the different properties of the ascending and descending Loop of Henle are important for urine formation.
    11. How does the structure of the kidney and its nephrons differ in mammals that live in aquatic, mesic, and arid habitats?
    12. What is the vasa recta?  What is its role in urine formation? 
    13. Why is inulin used to measure the glomerular filtration rate.  Give an example of how it works.
    14. What is the glomerular filtration rate when urine production is 0.5 l/hr and the inulin concentration in the urine is 25 times that of the blood?
    15. What is renal clearance?  What are the expected values for substances that are filtered only?  Filtered and resorbed?  Filtered and secreted?
    16. What is the tubular resorption maximum?  What happens when it is exceded?
    17. The normal GFR is 125 ml/min and the normal concentration of blood glucose is 1 mg/ml.  
      1. How many mg/min of glucose are reabsorbed by the kidneys by a person with these values, if there is no glucose in the urine?
      2. The kidney can reabsorb a maximum of 375 mg/ml of glucose.  What would the blood glucose level (in mg/ml) have to exceed before glucose is excreted in the urine? 
      3. Why wouldn't a normal person be expected to excrete glucose, even after eating a sugar-rich meal?
    18. Renal Function
      1. Calculate the GFR in L/hr from the following values
        1. [Inulin] in urine: 2.0 mg/L
        2. [Inulin] in Plasma: 0.02 mg/L
        3. Urine Output: 50 ml/hr
      2. For the same individual, calculate the apparent GFR based on urea
        1. [urea] in urine: 55.0 mg/L
        2. [urea] in Plasma: 0.5 mg/L
        3. Urine Output: 50 ml/hr
      3. Is there a net secretion or reabsorption of Urea in the renal tubules? What is the amount in mg/L?
    19. Describe how ADH can regulate water retention/loss.
    20. How does ADH (antidiuretic hormone) regulate urine osmolarity and volume?
    21. What is the role of ADH (AntiDiuretic Hormone) in regulating urine volume and osmolarity in the mammalian kidney?
    22. How do alcohol and caffeine affect urine production?
    23. What are the three most common nitrogenous end products found in animals?  What are their advantages and the disadvantages with the major three?  Discuss waste of organic carbon, energy loss, water loss, toxicity and water solubility.
    24. Compare and contrast the three main methods of excreting nitrogenous wastes in animals in terms of water conservation.
    25. Why do aquatic organisms that are capable of at least a transient terrestrial existence accumulate urea, instead of ammonia, when on land? What is the advantage of switching between ammonia and urea excretion?
    26. Which major groups of animals excrete uric acid?  What are the two major evolutionary advantages for them in excreting uric acid?
    27. Aquatic birds such as ducks excrete uric acid even though they almost always are near a source of drinking water.  Why?
    28. Discuss the processes and locations involved in water and salt regulation in insects.
    29. If insect Malpighian tubules do not use ultrafiltration, how then do they produce excreta?
    30. Insects excrete nitrogenous wastes from protein metabolism primarily as solid uric acid. How do they produce this solid?

    Define, explain the importance to excretion, and give an example (where appropriate) of the following

    1. Ammonia
    2. Urea
    3. Uric acid
    4. Cloaca
    5. Gout
    6. Renal cortex
    7. Renal medulla
    8. Nephron
    9. Glomerulus
    10. Bowman�s capsule
    11. Proximal convoluted tubule
    12. Loop of Henle
    13. Distal convoluted tubule
    14. Collecting duct
    15. Ultrafiltration
    16. Hydrostatic pressure
    17. Primary urine
    18. Osmotic pressure
    19. Vasa recta
    20. active secretion
    21. active reabsorption
    22. Glomerular Filtration Rate.
    23. Renal clearance
    24. Tubular maximum
    25. Inulin
    26. Antidiuretic hormone
    27. Malpighian tubule

    Chapter 30 Desert Mammals
    REVIEW QUESTIONS

    1. Why is it more difficult for small animals to remain cool under hot desert conditions?
    2. Explain what is illustrated in HWA Fig. 30.1 regarding body mass and evaporation for the upper line (walking animals).
    3. Explain the advantage of being large in a hot environment, i.e., explain the importance of large body size large in a hot environment.
    4. Explain Fig 30.4. Why do wildebeests and zebras have different seasonal distributions than do gazelles?
    5. Compare water gains and losses in a water-dependent versus a water-independent large desert mammal (Fig. 30.6).
    6. Why do many large desert herbivores do most of their feeding around dawn rather than other times of the day?
    7. What are the main advantages of the high amplitude cycles of body temperatures in oryxes during the summer (Figure 3011a)?
    8. Why do camels have higher amplitude daily body temperature cycles when water is not available?
    9. Why do camels have lower amplitude daily body temperature cycles when water is available?
    10. What is the most important reason that camels can lose more body water than humans?
    11. Compare and contrast adaptations for surviving in hot dry climates in small desert mammals such as kangaroo rats and large water independent desert mammals such as Oryx.