1. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings PowerPoint Lectures for Biology, Seventh Edition Neil Campbell and Jane Reece Lectures by Chris Romero Chapter 40 Basic Principles of Animal Form and Function

2. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Overview: Diverse Forms, Common Challenges Animals inhabit almost every part of the biosphere All animals face a similar set of problems, including how to nourish themselves The comparative study of animals reveals that form and function are closely correlated

3. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings

4. Anatomy is the study of the structure of an organism Physiology is the study of the functions an organism performs

5. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Concept 40.1: Physical laws and the environment constrain animal size and shape Physical laws and the need to exchange materials with the environment place limits on the range of animal forms

6. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Physical Laws and Animal Form The ability to perform certain actions depends on an animal’s shape and size Evolutionary convergence reflects different species’ adaptations to a similar environmental challenge Video: Shark Eating Seal Video: Shark Eating Seal Video: Galápagos Sea Lion Video: Galápagos Sea Lion

7. LE 40-2 Tuna Shark Penguin Dolphin Seal

8. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Exchange with the Environment An animal’s size and shape directly affect how it exchanges energy and materials with its surroundings Exchange occurs as substances dissolved in the aqueous medium diffuse and are transported across the cells’ plasma membranes

9. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings A single-celled protist living in water has a sufficient surface area of plasma membrane to service its entire volume of cytoplasm Video: Hydra Eating Daphnia Video: Hydra Eating Daphnia

10. LE 40-3 Diffusion Mouth Diffusion Two cell layers Single cell Diffusion Gastrovascular cavity

11. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Multicellular organisms with a sac body plan have body walls that are only two cells thick, facilitating diffusion of materials

12. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings More complex organisms have highly folded internal surfaces for exchanging materials

13. LE 40-4 Digestive system Circulatory system Excretory system Interstitial fluid Cells Nutrients Heart Animal body Respiratory system Blood CO 2 Food Mouth External environment O2O2 50 µm A microscopic view of the lung reveals that it is much more spongelike than balloonlike. This construction provides an expansive wet surface for gas exchange with the environment (SEM). 10 µm Inside a kidney is a mass of microscopic tubules that exchange chemicals with blood flowing through a web of tiny vessels called capillaries (SEM). The lining of the small intestine, a digestive organ, is elaborated with fingerlike projections that expand the surface area for nutrient absorption (cross-section, SEM). Unabsorbed matter (feces) Metabolic waste products (urine) Anus 0.5 cm

14. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Most animals are composed of specialized cells organized into tissues that have different functions Tissues make up organs, which together make up organ systems Concept 40.2: Animal form and function are correlated at all levels of organization

15. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Different tissues have different structures that are suited to their functions Tissues are classified into four main categories: epithelial, connective, muscle, and nervous Tissue Structure and Function

16. LE 40-5_1 EPITHELIAL TISSUE Stratified columnar epithelium Simple columnar epithelium Pseudostratified ciliated columnar epithelium Columnar epithelia, which have cells with relatively large cytoplasmic volumes, are often located where secretion or active absorption of substances is an important function. Stratified squamous epithelia Simple squamous epithelia Cuboidal epithelia Basement membrane 40 µm

17. LE 40-5_2 CONNECTIVE TISSUE Collagenous fiber Elastic fiber 120 µm 100 µm Chondrocytes Chondroitin sulfate Cartilage 150 µm Adipose tissue Fat droplets Blood Red blood cells White blood cell 55 µm Plasma Bone Central canal 700 µm Osteon 30 µm Fibrous connective tissue Nuclei Loose connective tissue

18. LE 40-5_3 MUSCLE TISSUE Multiple nuclei 100 µm Skeletal muscle Cardiac muscle Smooth muscle Neuron Muscle fiber Sarcomere Intercalated disk Nucleus 50 µm Nucleus 25 µm Muscle fibers Process Nucleus 50 µm Cell body NERVOUS TISSUE

19. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Epithelial Tissue Epithelial tissue covers the outside of the body and lines the organs and cavities within the body It contains cells that are closely joined

20. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Connective Tissue Connective tissue mainly binds and supports other tissues It contains sparsely packed cells scattered throughout an extracellular matrix

21. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Muscle Tissue Muscle tissue consists of long cells called muscle fibers, which contract in response to nerve signals It is divided in the vertebrate body into three types: skeletal, cardiac, and smooth

22. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Nervous Tissue Nervous tissue senses stimuli and transmits signals throughout the animal

23. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Organs and Organ Systems In all but the simplest animals, tissues are organized into organs In some organs, the tissues are arranged in layers

24. LE 40-6 Lumen of stomach Mucosa: an epithelial layer that lines the lumen Submucosa: a matrix of connective tissue that contains blood vessels and nerves Muscularis: consists mainly of smooth muscle tissue Serosa: a thin layer of connective and epithelial tissue external to the muscularis 0.2 mm

25. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Organ systems carry out the major body functions of most animals

26. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings

27. All organisms require chemical energy for growth, repair, physiological processes, regulation, and reproduction Concept 40.3: Animals use the chemical energy in food to sustain form and function

28. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Bioenergetics, the flow of energy through an animal, limits behavior, growth, and reproduction It determines how much food an animal needs Studying bioenergetics tells us much about an animal’s adaptations Bioenergetics

29. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Energy Sources and Allocation Animals harvest chemical energy from food Energy-containing molecules from food are usually used to make ATP, which powers cellular work After the needs of staying alive are met, remaining food molecules can be used in biosynthesis

30. LE 40-7 External environment Organic molecules in food Animal body Digestion and absorption Nutrient molecules in body cells Carbon skeletons Cellular respiration Biosynthesis: growth, storage, and reproduction Cellular work ATP Heat Energy lost in urine Heat Energy lost in feces

31. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Metabolic rate is the amount of energy an animal uses in a unit of time One way to measure it is to determine the amount of oxygen consumed or carbon dioxide produced Quantifying Energy Use

32. LE 40-8 This photograph shows a ghost crab in a respirometer. Temperature is held constant in the chamber, with air of known O 2 concentration flowing through. The crab’s metabolic rate is calculated from the difference between the amount of O 2 entering and the amount of O 2 leaving the respirometer. This crab is on a treadmill, running at a constant speed as measurements are made. Similarly, the metabolic rate of a man fitted with a breathing apparatus is being monitored while he exercises on a stationary bike.

33. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings An animal’s metabolic rate is closely related to its bioenergetic strategy Birds and mammals are mainly endothermic: Their bodies are warmed mostly by heat generated by metabolism Endotherms typically have higher metabolic rates Bioenergetic Strategies

34. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Amphibians and reptiles other than birds are ectothermic: They gain their heat mostly from external sources Ectotherms generally have lower metabolic rates

35. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Metabolic rates are affected by many factors besides whether an animal is an endotherm or ectotherm Two of these factors are size and activity Influences on Metabolic Rate

36. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Size and Metabolic Rate Metabolic rate per gram is inversely related to body size among similar animals Researchers continue to search for the causes of this relationship

37. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings The basal metabolic rate (BMR) is the metabolic rate of an endotherm at rest The standard metabolic rate (SMR) is the metabolic rate of an ectotherm at rest Activity greatly affects metabolic rate In general, maximum metabolic rate is inversely related to the duration of the activity Activity and Metabolic Rate

38. LE 40-9 A = 60-kg alligator A = 60-kg human Key Existing intracellular ATP ATP from glycolysis ATP from aerobic respiration Time interval 1 second 1 minute 1 hour 1 day 1 week 500 100 50 10 5 1 0.5 0.1 Maximum metabolic rate (kcal/min; log scale) AH A H A H A H A H

39. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Different species use energy and materials in food in different ways, depending on their environment Use of energy is partitioned to BMR (or SMR), activity, homeostasis, growth, and reproduction Energy Budgets

40. LE 40-10 800,000 Endotherms 340,000 Annual energy expenditure (kcal/yr) Basal (standard) metabolism Reproduction Temperature regulation Growth Activity 60-kg female human from temperate climate 4-kg male Adélie penguin from Antarctica (brooding) 4,000 0.025-kg female deer mouse from temperate North America 4-kg female python from Australia 8,000 Ectotherm Total annual energy expenditures. The slices of the pie charts indicate energy expenditures for various functions. Energy expenditures per unit mass (kcal/kgday). Comparing the daily energy expenditures per kg of body weight for the four animals reinforces two important concepts of bioenergetics. First, a small animal, such as a mouse, has a much greater energy demand per kg than does a large animal of the same taxonomic class, such as a human (both mammals). Second, note again that an ectotherm, such as a python, requires much less energy per kg than does an endotherm of equivalent size, such as a penguin. Energy expenditure per unit mass (kcal/kgday) 438 233 36.5 5.5 Python Human Deer mouse Adélie penguin

41. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Concept 40.4: Animals regulate their internal environment within relatively narrow limits The internal environment of vertebrates is called the interstitial fluid and is very different from the external environment Homeostasis is a balance between external changes and the animal’s internal control mechanisms that oppose the changes

42. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Regulating and conforming are two extremes in how animals cope with environmental fluctuations A regulator uses internal control mechanisms to moderate internal change in the face of external, environmental fluctuation A conformer allows its internal condition to vary with certain external changes Regulating and Conforming

43. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Mechanisms of homeostasis moderate changes in the internal environment A homeostatic control system has three functional components: a receptor, a control center, and an effector Mechanisms of Homeostasis Animation: Negative Feedback Animation: Negative Feedback Animation: Positive Feedback Animation: Positive Feedback

44. LE 40-11 Response No heat produced Room temperature decreases Room temperature increases Set point Too hot Set point Heater turned off Too cold Set point Control center: thermostat Heater turned on Response Heat produced

45. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Most homeostatic control systems function by negative feedback, where buildup of the end product shuts the system off In positive feedback, a change in a variable triggers mechanisms that amplify rather than reverse the change

46. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Concept 40.5: Thermoregulation contributes to homeostasis and involves anatomy, physiology, and behavior Thermoregulation is the process by which animals maintain an internal temperature within a tolerable range

47. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Ectotherms include most invertebrates, fishes, amphibians, and non-bird reptiles Endotherms include birds and mammals In general, ectotherms t olerate greater variation in internal temperature than endotherms Ectotherms and Endotherms

48. LE 40-12 River otter (endotherm) Largemouth bass (ectotherm) Ambient (environmental) temperature (°C) 01020 30 40 Body temperature (°C) 30 20 10

49. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Endothermy is more energetically expensive than ectothermy It buffers the animal’s internal temperatures against external fluctuations It also enables the animal to maintain a high level of aerobic metabolism

50. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Modes of Heat Exchange Organisms exchange heat by four physical processes: conduction, convection, radiation, and evaporation

51. LE 40-13 Radiation Evaporation Conduction Convection

52. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Balancing Heat Loss and Gain In thermoregulation, physiological and behavioral adjustments balance heat loss and gain Five general adaptations help animals thermoregulate: – Insulation – Circulatory adaptations – Cooling by evaporative heat loss – Behavioral responses – Adjusting metabolic heat production

53. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Insulation Insulation is a major thermoregulatory adaptation in mammals and birds It reduces heat flow between an animal and its environment Examples are skin, feathers, fur, and blubber In mammals, the integumentary system acts as insulating material

54. LE 40-14 Epidermis Dermis Hypodermis Adipose tissue Blood vessels Hair Sweat pore Sweat gland Muscle Nerve Oil gland Hair follicle

55. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Many endotherms and some ectotherms can alter the amount of blood flowing between the body core and the skin In vasodilation, blood flow in the skin increases, facilitating heat loss In vasoconstriction, blood flow in the skin decreases, lowering heat loss Circulatory Adaptations

56. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Many marine mammals and birds have an arrangement of blood vessels called a countercurrent heat exchanger Countercurrent heat exchangers are important for reducing heat loss

57. LE 40-15 Blood flow Vein Artery Pacific bottlenose dolphin Canada goose Vein Artery 33° 27° 18° 9° 35°C 30° 20° 10°

58. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Some bony fishes and sharks also have countercurrent heat exchangers

59. LE 40-16a Bluefin tuna Body cavity 31° 29° 25° 27° 23° 21°

60. LE 40-16b Vein Artery Skin Capillary network within muscle Blood vessels in gills Heart Artery and vein under the skin Dorsal aorta Great white shark

61. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Many endothermic insects have countercurrent heat exchangers that help maintain a high temperature in the thorax

62. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings

63. Cooling by Evaporative Heat Loss Many types of animals lose heat through evaporation of water in sweat Panting augments the cooling effect in birds and many mammals Bathing moistens the skin, helping to cool an animal down

64. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings

65. Both endotherms and ectotherms use behavioral responses to control body temperature Some terrestrial invertebrates have postures that minimize or maximize absorption of solar heat Behavioral Responses

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67. Adjusting Metabolic Heat Production Some animals can regulate body temperature by adjusting their rate of metabolic heat production Many species of flying insects use shivering to warm up before taking flight

68. LE 40-20 PREFLIGHT WARMUP FLIGHT Abdomen Thorax Time from onset of warmup (min) 4 2 0 40 35 30 25 Temperature (°C)

69. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Mammals regulate body temperature by negative feedback involving several organ systems In humans, the hypothalamus (a part of the brain) contains nerve cells that function as a thermostat Feedback Mechanisms in Thermoregulation

70. LE 40-21 Thermostat in hypothalamus activates cooling mechanisms. Increased body temperature (such as when exercising or in hot surroundings) Body temperature decreases; thermostat shuts off cooling mechanisms. Sweat glands secrete sweat that evaporates, cooling the body. Blood vessels in skin dilate: capillaries fill with warm blood; heat radiates from skin surface. Body temperature increases; thermostat shuts off warming mechanisms. Decreased body temperature (such as when in cold surroundings) Blood vessels in skin constrict, diverting blood from skin to deeper tissues and reducing heat loss from skin surface. Skeletal muscles rapidly contract, causing shivering, which generates heat. Thermostat in hypothalamus activates warming mechanisms. Homeostasis: Internal body temperature of approximately 36–38°C

71. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Adjustment to Changing Temperatures In acclimatization, many animals adjust to a new range of environmental temperatures over a period of days or weeks Acclimatization may involve cellular adjustments or (as in birds and mammals) adjustments of insulation and metabolic heat production

72. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Torpor and Energy Conservation Torpor is a physiological state in which activity is low and metabolism decreases Torpor enables animals to save energy while avoiding difficult and dangerous conditions Hibernation is long-term torpor that is an adaptation to winter cold and food scarcity

73. LE 40-22 Actual metabolism Additional metabolism that would be necessary to stay active in winter Arousals 200 100 0 Body temperature Outside temperature Burrow temperature 35 30 25 20 15 10 5 0 –5 –10 –15 Temperature (°C) JuneAugustOctoberDecemberFebruaryApril Metabolic rate (kcal per day)

74. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Estivation, or summer torpor, enables animals to survive long periods of high temperatures and scarce water supplies Daily torpor is exhibited by many small mammals and birds and seems adapted to feeding patterns