Basic Principles of Animal Form and Function

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Edition Neil Campbell and Jane Reece Lectures by Chris

1 Chapter 40 Basic Principles of Animal Form and Function PowerPoint Lecture Presentations for Biology Eighth Edition Neil Campbell and Jane Reece Lectures by Chris Romero, updated by Erin Barley with contributions from Joan Sharp 1

2 Tissue Structure and Function Different tissues have different structures that are suited to their functions Tissues are classified into four main categories: epithelial connective muscle nervous 2

columnar (like bricks on end), or squamous (like floor tiles) The arrangement of epithelial cells may be simple

3 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 The shape of epithelial cells may be cuboidal (like dice), columnar (like bricks on end), or squamous (like floor tiles) The arrangement of epithelial cells may be simple (single cell layer), stratified (multiple tiers of cells), or pseudostratified (a single layer of cells of varying length) 3

4 Fig. 40-5a Cuboidal epithelium Epithelial Tissue Simple columnar epithelium Pseudostratified ciliated columnar epithelium Stratified squamous epithelium Simple squamous epithelium 4

5 Connective Tissue Connective tissue mainly binds and supports other tissues It contains sparsely packed cells scattered throughout an extracellular matrix The matrix consists of fibers in a liquid, jellylike, or solid foundation 5

6 There are three types of connective tissue fiber, all made of protein: Collagenous fibers provide strength and flexibility Elastic fibers stretch and snap back to their original length Reticular fibers join connective tissue to adjacent tissues 6

7 Connective tissue contains cells, including Fibroblasts that secrete the protein of extracellular fibers Macrophages (or fibrocytes) that are involved in the immune system 7

In vertebrates, the fibers and foundation combine to form six major types of connective tissue: Loose connective tissue binds epithelia to underlying tissues and holds organs in

8 In vertebrates, the fibers and foundation combine to form six major types of connective tissue: Loose connective tissue binds epithelia to underlying tissues and holds organs in place Cartilage is a strong and flexible support material Fibrous connective tissue is found in tendons, which attach muscles to bones, and ligaments, which connect bones at joints 8

9 Adipose tissue stores fat for insulation and fuel Blood is composed of blood cells and cell fragments in blood plasma Bone is mineralized and forms the skeleton To learn as it is here!! 9

10 700 µm 55 µm 30 µm 150 µm 120 µm 100 µm Fig. 40-5c Connective Tissue Collagenous fiber Loose connective tissue Chondrocytes Cartilage Elastic fiber Chondroitin sulfate Nuclei Fibrous connective tissue Adipose tissue Fat droplets Osteon Bone Blood White blood cells Central canal Plasma 10 Red blood cells

muscle, or striated muscle, is responsible for voluntary movement Smooth muscle is

11 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 muscle, or striated muscle, is responsible for voluntary movement Smooth muscle is responsible for involuntary body activities Cardiac muscle is responsible for contraction of the heart 11

12 Fig. 40-5j Muscle Tissue Multiple nuclei Muscle fiber Skeletal muscle 100 µm Sarcomere Nucleus Intercalated disk Cardiac muscle 50 µm Smooth muscle Nucleus Muscle fibers 25 µm 12

13 Nervous Tissue Nervous tissue senses stimuli and transmits signals throughout the animal Nervous tissue contains: Neurons, or nerve cells, that transmit nerve impulses Glial cells, or glia, that help nourish, insulate, and replenish neurons 13

14 Fig. 40-5n Nervous Tissue 40 µm Dendrites Cell body Glial cells Axon Neuron Axons 15 µm Blood vessel 14

15 Table 40-1 Organs: groups of tissues organized to carry out specific function Organ system: group of organs organized to carry out specific function 15

Coordination and Control Control and coordination within a body depend on the endocrine system and the nervous system The endocrine system transmits

16 Coordination and Control Control and coordination within a body depend on the endocrine system and the nervous system The endocrine system transmits chemical signals called hormones to receptive cells throughout the body via blood The nervous system transmits information between specific locations 16

Fig. 40-6 Stimulus Endocrine cell Stimulus Neuron Hormone Signal travels

Signal Axon Signal travels along axon to a specific location.

17 Fig Stimulus Endocrine cell Stimulus Neuron Hormone Signal travels everywhere via the bloodstream. Signal Axon Signal travels along axon to a specific location. Blood vessel Signal Axons Signaling in the endocrine and nervous systems Response (a) Signaling by hormones Response (b) Signaling by neurons 17

18 Homeostasis Organisms use homeostasis to maintain a steady state or internal balance regardless of external environment In humans, body temperature, blood ph, and glucose concentration are each maintained at a constant level 18

Regulating and Conforming Animals manage their internal environment by regulating or conforming to the external environment A regulator uses internal control

19 Regulating and Conforming Animals manage their internal environment by regulating or conforming to the external environment 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 19

Fig. 40-7 Body temperature ( C) 40 River otter (temperature regulator) 30 20

environmental temperatures in an aquatic temperature regulator and an aquatic

20 Fig Body temperature ( C) 40 River otter (temperature regulator) Largemouth bass (temperature conformer) The relationship between body and environmental temperatures in an aquatic temperature regulator and an aquatic temperature conformer Ambient (environmental) temperature (ºC) 20

21 Mechanisms of Homeostasis Mechanisms of homeostasis moderate changes in the internal environment For a given variable, fluctuations above or below a set point serve as a stimulus; these are detected by a sensor and trigger a response The response returns the variable to the set point Animation: Negative Feedback Animation: Positive Feedback 21

Fig. 40-8 A nonliving example of negative feedback: control of room temperature Room temperature decreases Response: Heater turned off Set point: 20ºC

22 Fig A nonliving example of negative feedback: control of room temperature Room temperature decreases Response: Heater turned off Set point: 20ºC Stimulus: Control center (thermostat) reads too hot Room temperature increases Stimulus: Control center (thermostat) reads too cold Response: Heater turned on 22

23 Feedback Loops in Homeostasis The dynamic equilibrium of homeostasis is maintained by negative feedback, which helps to return a variable to either a normal range or a set point Most homeostatic control systems function by negative feedback, where buildup of the end product shuts the system off Positive feedback loops occur in animals, but do not usually contribute to homeostasis 23

24 Concept 40.3: Homeostatic processes for thermoregulation involve form, function, and behavior Thermoregulation is the process by which animals maintain an internal temperature within a tolerable range 24

25 Endothermy and Ectothermy Endothermic animals generate heat by metabolism; birds and mammals are endotherms Ectothermic animals gain heat from external sources; ectotherms include most invertebrates, fishes, amphibians, and nonavian reptiles 25

26 Fig (a) A walrus, an endotherm (b) A lizard, an ectotherm 26

27 Balancing Heat Loss and Gain Organisms exchange heat by four physical processes: conduction, convection, radiation, and evaporation 27

28 Fig Radiation Evaporation Convection Conduction 28

29 Five general adaptations help animals thermoregulate: Insulation Circulatory adaptations Cooling by evaporative heat loss Behavioral responses Adjusting metabolic heat production 29

30 Insulation Insulation is a major thermoregulatory adaptation in mammals and birds Skin, feathers, fur, and blubber reduce heat flow between an animal and its environment 30

31 Circulatory Adaptations (by vascular system) Regulation of blood flow near the body surface significantly affects thermoregulation 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 31

32 The arrangement of blood vessels in many marine mammals and birds allows for countercurrent exchange Countercurrent heat exchangers transfer heat between fluids flowing in opposite directions Countercurrent heat exchangers are an important mechanism for reducing heat loss 32

33 Fig Canada goose Bottlenose dolphin Artery 35ºC Vein 33º Blood flow Vein Artery 30º 27º 20º 18º 10º 9º Countercurrent heat exchangers 33

Cooling by Evaporative Heat Loss and Behavioral Responses Many types of animals lose heat through evaporation of water in sweat Panting increases the cooling effect in birds

34 Cooling by Evaporative Heat Loss and Behavioral Responses Many types of animals lose heat through evaporation of water in sweat Panting increases the cooling effect in birds and many mammals Sweating or bathing moistens the skin, helping to cool an animal down Both endotherms and ectotherms use behavioral responses to control body temperature 34

35 Adjusting Metabolic Heat Production Some animals can regulate body temperature by adjusting their rate of metabolic heat production Heat production is increased by muscle activity such as moving or shivering Some ectotherms can also shiver to increase body temperature 35

Fig. 40-15 Temperature (ºC) 40 PREFLIGHT

36 Fig Temperature (ºC) 40 PREFLIGHT PREFLIGHT WARM-UP FLIGHT Thorax 35 Preflight warm-up in the hawkmoth 30 Abdomen Time from onset of warm-up (min) 36

37 Concept 40.4: Energy requirements are related to animal size, activity, and environment Bioenergetics is the overall flow and transformation of energy in an animal It determines how much food an animal needs and relates to an animal s size, activity, and environment Metabolic rate is the amount of energy an animal uses in a unit of time 37

38 Minimum Metabolic Rate and Thermoregulation Basal metabolic rate (BMR) is the metabolic rate of an endotherm at rest at a comfortable temperature Standard metabolic rate (SMR) is the metabolic rate of an ectotherm at rest at a specific temperature 38

Human Sheep Horse Elephant 1 Cat Dog 10 1 Shrew Rat Mouse Harvest mouse

39 BMR (L O 2 /hr) (log scale) Fig a 10 3 The relationship of metabolic rate to body 10 2 size 10 Human Sheep Horse Elephant 1 Cat Dog 10 1 Shrew Rat Mouse Harvest mouse Ground squirrel (a) Relationship of BMR to body size Body mass (kg) (log scale) 39

Fig. 40-19b BMR (L O2/hr) (per kg) 8 7 6 5 4 Shrew

Harvest mouse 2 1 0 Mouse Sheep Rat Cat Human

1 10 10 2 10 3 Body mass (kg) (log scale) 40 (b)

40 Fig b BMR (L O2/hr) (per kg) Shrew The relationship of metabolic rate to body size 3 Harvest mouse Mouse Sheep Rat Cat Human Elephant Dog Ground squirrel Horse Body mass (kg) (log scale) 40 (b) Relationship of BMR per kilogram of body mass to body size

Fig. 40-20 Annual energy expenditure (kcal/hr) Energy budgets for four animals Endotherms Ectotherm 800,000 Reproduction Basal Thermoregulation (standard) metabolism Growth Activity 340,000

41 Fig Annual energy expenditure (kcal/hr) Energy budgets for four animals Endotherms Ectotherm 800,000 Reproduction Basal Thermoregulation (standard) metabolism Growth Activity 340,000 4,000 8, kg female human from temperate climate 4-kg male Adélie penguin from Antarctica (brooding) kg female deer mouse from temperate North America 4-kg female eastern indigo snake 41

42 42

43 Thank you for your attention and participation! 43

44 You should now be able to: 1. Distinguish among the following sets of terms: collagenous, elastic, and reticular fibers; regulator and conformer; positive and negative feedback; basal and standard metabolic rates 2. Relate structure with function and identify diagrams of the following animal tissues: epithelial, connective tissue (six types), muscle tissue (three types), and nervous tissue 44

45 3. Compare and contrast the nervous and endocrine systems 4. Define thermoregulation and explain how endotherms and ectotherms manage their heat budgets 5. Describe how a countercurrent heat exchanger may function to retain heat within an animal body 6. Define bioenergetics 7. Define metabolic rate and explain how it can be determined for animals 45

Basic Principles of Animal Form and Function

Chapter Fig. - Basic Principles of Animal Form and Function Anatomy Physiology PowerPoint Lecture Presentations for Biology Eighth Edition Neil Campbell and Jane Reece Lectures by Chris Romero, updated