Principles of animal physiology / 2nd ed.

Table Of Contents:
Preface xviii
Acknowledgments xxix

PART ONE THE CELLULAR BASIS OF ANIMAL PHYSIOLOGY 1(246)

Introduction to Physiological Principles 2(18)

Overview 4(1)

Physiology: Past and Present 4(6)

A Brief History of Animal Physiology 4(2)

Subdisciplines in Physiological Research 6(1)

Physiological subdisciplines can be distinguished by the biological level of organization 6(2)

Physiological subdisciplines can be distinguished by the process that generates variation 8(1)

Animal physiology can be a pure or an applied science 8(1)

Box 1.1 Methods and Model Systems August Krogh Models in Animal Physiology 9(1)

Unifying Themes in Physiology 10(10)

Physics and Chemistry: The Basis of Physiology 10(1)

Mechanical theory helps us understand how organisms work 10(1)

Electrical potentials are a fundamental physiological currency 11(1)

Biochemical and physiological patterns are influenced by body size 11(1)

Physiological Regulation 12(1)

Homeostasis is the maintenance of internal constancy 12(1)

Feedback loops control physiological pathways 12(1)

Negative feedback loops maintain homeostasis 13(1)

Positive feedback loops cause explosive responses 13(1)

Phenotype, Genotype, and the Environment 13(1)

A single genotype results in more than one phenotype 14(1)

Acclimation and acclimatization result in reversible phenotypic changes 14(1)

Physiology and Evolution 15(1)

What is adaptation? 15(1)

Not all differences are evolutionary adaptations 16(1)

Evolutionary relationships influence morphology and physiology 16(1)

Summary 17(1)

Synthesis Questions 18(1)

For Further Reading 18(2)

Chemistry, Biochemistry, and Cell Physiology 20(70)

Overview 22(1)

Chemistry 22(13)

Energy 22(1)

Food webs transfer energy 23(1)

Energy is stored in electrochemical gradients 23(1)

Thermal energy is the movement of molecules 24(1)

Chemical Bonds 25(1)

Covalent bonds involve shared electrons 25(1)

Weak bonds control macromolecular structure 26(1)

Weak bonds are sensitive to temperature 27(1)

Properties of Water 27(1)

The properties of water are unique 27(1)

Solutes influence the physical properties of water 28(1)

Solutes move through water by diffusion 29(1)

Solutes in biological systems impose osmotic pressure 29(1)

Differences in osmolarity can alter cell volume 30(1)

pH and the lonization of Water 30(1)

Neutrality is not always at pH 7 31(1)

Acids and bases alter the pH of water 31(2)

Both pH and temperature affect the ionization of biological molecules 33(1)

Buffers limit changes in pH 34(1)

Biochemistry 35(29)

Enzymes 35(1)

Enzymes accelerate reactions by reducing the reaction activation energy 35(1)

Box 2.1 Mathematical Underpinnings Thermodynamics 36(1)

Enzyme kinetics describe enzymatic properties 37(2)

The physicochemical environment alters enzyme kinetics 39(1)

Allosteric and covalent regulation control enzymatic rates 40(1)

Enzymes convert nutrients to reducing energy 40(2)

ATP is a carrier of free energy 42(1)

Proteins 43(1)

Proteins are polymers of amino acids 43(1)

Proteins are folded into three-dimensional shapes 44(1)

Molecular chaperones help proteins fold 45(1)

Carbohydrates 46(1)

Animals use monosaccharides for energy and biosynthesis 46(1)

Complex carbohydrates perform many functional and structural roles 47(1)

Gluconeogenesis builds glucose from noncarbohydrate precursors 48(1)

Glycolysis is a low-efficiency, high-velocity pathway 49(1)

Mitochondria oxidize glycolytic pyruvate and NADH under aerobic conditions 50(1)

Terminal dehydrogenases oxidize NADH under anaerobic conditions 51(1)

Lipids 52(1)

Fatty acids are long aliphatic chains produced from acetyl CoA 52(1)

Fatty acids are oxidized in mitochondrial β-oxidation 53(1)

Fatty acids can be converted to ketone bodies 54(1)

Triglyceride is the major form of lipid storage 54(1)

Phospholipids predominate in biological membranes 55(1)

Steroids share a multiple ring structure 56(1)

Mitochondrial Metabolism 57(1)

The TCA cycle uses acetyl CoA to generate reducing equivalents 57(1)

The ETS generates a proton gradient, heat, and reactive oxygen species 58(1)

The F1F0 ATPase uses the proton motive force to generate ATP 59(1)

Creatine phosphokinase enhances energy stores and transfer 60(1)

Integration of Pathways of Energy Metabolism 60(1)

Oxygen and ATP control the balance between glycolysis and OXPHOS 61(1)

Physical properties of fuels influence fuel selection 61(1)

Box 2.2 Methods and Model Systems Metabolic Rate 62(1)

Fuel selection can be calculated from the respiratory quotient 62(1)

Energetic intermediates regulate the balance between anabolism and catabolism 63(1)

Cell Physiology 64(26)

Membrane Structure 64(1)

The lipid profile affects membrane properties 64(1)

Lipid membranes are heterogeneous 65(1)

Environmental stress can alter membrane fluidity 65(1)

Membranes possess integral and peripheral proteins 66(1)

Transport Across Cellular Membranes 66(1)

Lipid-soluble molecules cross membranes by passive diffusion 66(1)

Membrane proteins can facilitate the diffusion of impermeant molecules 67(1)

Active transporters use energy to pump molecules against gradients 68(1)

Membrane Potential 69(1)

The interior of the membrane is electronegative at rest 69(1)

Ionic concentration gradients and permeability establish membrane potential 69(2)

Potassium plays the major role in establishing membrane potential 71(1)

The Na+/K+ ATPase establishes concentration gradients 71(1)

Changes in membrane permeability alter membrane potential 71(1)

Box 2.3 Mathematical Underpinnings The Goldman Equation 72(1)

Subcellular Organization 72(1)

Mitochondria are the powerhouse of the cell 73(1)

The cytoskeleton controls cell shape and directs intracellular movement 74(1)

The endoplasmic reticulum and Golgi apparatus mediate vesicular traffic 75(2)

The extracellular matrix mediates interactions between cells 77(1)

Physiological Genetics and Genomics 78(1)

Nucleic acids are polymers of nucleotides 78(1)

DNA is a double-stranded α-helix packaged into chromosomes 79(1)

DNA is organized into genomes 80(1)

Transcriptional control acts at gene regulatory regions 80(2)

RNA degradation influences RNA levels 82(1)

Global changes in translation control many pathways 82(1)

Cells rapidly reduce protein levels through protein degradation 82(1)

Protein variants arise through gene duplications and rearrangements 83(1)

Ancient genome duplications contribute to physiological diversity 84(1)

Summary 85(2)

Review Questions 87(1)

Synthesis Questions 87(1)

Quantitative Questions 88(1)

For Further Reading 88(2)

Cell Signaling and Endocrine Regulation 90(52)

Overview 92(1)

The Biochemical Basis of Cell Signaling 93(17)

General Features of Cell Signaling 93(1)

Indirect signaling systems form a continuum 94(2)

The structure of the messenger determines the type of signaling mechanism 96(1)

Peptide Messengers 96(1)

Peptide messengers are released by exocytosis 97(1)

Peptide messengers dissolve in extracellular fluids 97(1)

Peptides bind to transmembrane receptors 98(1)

Steroid Messengers 99(1)

Steroids bind to carrier proteins 99(2)

Box 3.1 Evolution and Diversity Ecdysone: An Arthropod Steroid Hormone 101(1)

Steroids bind to intracellular receptors 102(1)

Biogenic Amines 102(1)

Thyroid hormones diffuse across the membrane 103(1)

Thyroid hormones are hydrophobic messengers 103(1)

Other Classes of Messenger 104(1)

Eicosanoids are lipid messengers 104(1)

Nitric oxide is a gaseous chemical messenger 104(1)

Purines can act as neurotransmitters and paracrines 105(1)

Communication of the Signal to the Target Cell 105(1)

Ligand-receptor interactions are specific 105(1)

Receptor type determines the cellular response 106(1)

Receptors have several domains 106(1)

A ligand may bind to more than one receptor 106(1)

Ligand-receptor binding obeys the law of mass action 107(1)

Receptor number can vary 107(1)

Receptor affinity for ligand can vary 108(1)

Ligand signaling must be inactivated 108(2)

Signal Transduction Pathways 110(12)

Intracellular Receptors 111(1)

Ligand-Gated Ion Channels 112(1)

Signal Transduction via Receptor-Enzymes 112(1)

Receptor guanylate cyclases generate cyclic GMP 113(1)

Receptor tyrosine kinases signal through Ras proteins 114(1)

Receptor serine/threonine kinases directly activate phosphorylation cascades 115(1)

Signal Transduction via G-Protein-Coupled Receptors 116(1)

Box 3.2 Evolution and Diversity G-Protein-Coupled Receptors 117(1)

G proteins can act through Ca2+-calmodulin 118(1)

G proteins can interact with amplifier enzymes 118(1)

Amplifier enzymes alter the concentration of second messengers 118(1)

Guanylate cyclase generates cGMP 118(1)

Phospholipase C generates phosphatidylinositol 119(1)

Cyclic AMP was the first second messenger to be discovered 120(1)

Signal transduction pathways can interact 121(1)

Introduction to Endocrine Systems 122(20)

Feedback Regulation 122(1)

Reflex control mediates long-distance regulation 122(2)

Pituitary hormones provide examples of several types of feedback loops 124(1)

The posterior pituitary secretes neurohormones 124(1)

Oxytocin is involved in a positive feedback loop 125(1)

Hypothalamic neurohormones regulate anterior pituitary hormones 125(1)

Many anterior pituitary hormones participate in third-order pathways 126(1)

Regulation of Glucose Metabolism 126(1)

The actions of insulin illustrate the principle of negative feedback 127(1)

Multiple types of feedback control can regulate blood glucose 127(1)

Insulin and glucagon illustrate the principle of antagonistic control 128(1)

Box 3.3 Applications Cell-to-Cell Communication and Diabetes 129(1)

Hormones can demonstrate additivity and synergism 129(1)

Hyperglycemic hormones control extracellular glucose in arthropods 130(1)

The Vertebrate Stress Response 131(1)

Stressful stimuli activate the sympathetic nervous system 131(1)

The sympathetic nervous system stimulates the adrenal medulla 132(1)

The hypothalamo-pituitary axis stimulates the adrenal cortex 133(1)

The structure of adrenal tissue varies among vertebrates 133(1)

Evolution of Endocrine Systems 133(4)

Summary 137(1)

Review Questions 138(1)

Synthesis Questions 139(1)

Quantitative Questions 139(1)

For Further Reading 140(2)

Neuron Structure and Function 142(54)

Overview 144(1)

Signaling in a Vertebrate Motor Neuron 145(20)

Electrical Signals in Neurons 146(1)

The Goldman equation describes the resting membrane potential 147(1)

Gated ion channels allow neurons to alter their membrane potentials 147(1)

Signals in the Dendrites and Cell Body 148(1)

Box 4.1 Methods and Model Systems Studying Ion Channels 149(1)

Graded potentials vary in magnitude 149(1)

Graded potentials are short-distance signals 150(1)

Graded potentials are integrated to trigger action potentials 151(2)

Signals in the Axon 153(1)

Voltage-gated channels shape the action potential 154(1)

Voltage-gated Na+ channels have two gates 155(3)

Action potentials transmit signals across long distances 158(1)

Vertebrate motor neurons are myelinated 158(1)

Axons conduct action potentials unidirectionally 158(2)

Action potential frequency carries information 160(1)

Signals Across the Synapse 161(1)

Intracellular Ca2+ regulates neurotransmitter release 161(1)

Action potential frequency influences neurotransmitter release 162(1)

Acetylcholine is the primary neurotransmitter at the vertebrate neuromuscular junction 162(1)

Signaling is terminated by acetylcholinesterase 163(1)

Postsynaptic cells express specific receptors 163(1)

Neurotransmitter amount and receptor activity influence signal strength 164(1)

Diversity of Neural Signaling 165(31)

Structural Diversity of Neurons 165(1)

Neurons can be classified based on their function 166(1)

Neurons can be classified based on their structure 167(1)

Neurons are associated with glial cells 168(1)

Diversity of Signal Conduction 169(1)

Voltage-gated ion channels are encoded by multiple genes 169(1)

Box 4.2 Evolution and Diversity The Evolution of Myelin Sheaths 170(1)

Voltage-gated Ca2+ channels can also be involved in action potentials 171(1)

Conduction speed varies among axons 172(1)

The cable properties of the axon influence current flow 172(1)

Intracellular and membrane resistance influence conduction speed 173(2)

Membrane capacitance influences the speed of conduction 175(2)

Giant axons have high conduction speed 177(1)

Box 4.3 Methods and Model Systems The Squid Giant Axon 178(1)

Myelinated neurons evolved in the vertebrates 179(1)

Myelination increases conduction speed 180(1)

Diversity of Synaptic Transmission 180(1)

Electrical and chemical synapses play different roles 180(1)

Chemical synapses have diverse structures 181(2)

There are many types of neurotransmitters 183(1)

Neurotransmitters can be excitatory or inhibitory 184(1)

Neurotransmitter receptors can be ionotropic or metabotropic 185(1)

Acetylcholine receptors can be ionotropic or metabotropic 185(2)

The biogenic amines play diverse physiological roles 187(1)

Neurons can synthesize more than one kind of neurotransmitter 188(1)

Neurotransmitter release varies depending on physiological state 189(1)

Evolution of neurons 190(1)

Only animals have voltage-gated Na+ channels 190(1)

Most organisms use chemicals for cell-to-cell communication 191(1)

Summary 191(1)

Review Questions 192(1)

Synthesis Questions 193(1)

Quantitative Questions 193(1)

For Further Reading 194(2)

Cellular Movement and Muscles 196(51)

Overview 198(1)

Cytoskeleton and Motor Proteins 198(14)

Microtubules 199(1)

Microtubules are composed of α-tubulin and β-tubulin 199(1)

Microtubules show dynamic instability 200(3)

Box 5.1 Evolution and Diversity Thermal Adaptation in Microtubules 203(1)

Microtubule polarity determines the direction of movement 203(1)

Kinesin and dynein move along microtubules 204(1)

Cilia and flagella are composed of microtubules 204(1)

Microfilaments 205(1)

Microfilaments are polymers of actin 206(1)

Actin polymerization can generate movement 207(1)

Actin uses myosin as a motor protein 208(1)

The sliding filament model describes actino-myosin activity 209(1)

Myosin activity is influenced by unitary displacement and duty cycle 210(2)

Muscle Structure and Regulation of Contraction 212(23)

Structure of the Vertebrate Striated Muscle Contractile Apparatus 214(1)

Striated muscle thick and thin filaments are arranged into sarcomeres 214(1)

Myosin II has a unique duty cycle and unitary displacement 215(1)

Sarcomeric organization determines contractile properties of the muscle cell 216(2)

Box 5.2 Genetics and Genomics Muscle Differentiation and Development 218(1)

Contraction and Relaxation in Vertebrate Striated Muscle 218(1)

Thin filament proteins confer Ca2+ sensitivity in striated muscle 219(2)

The troponin-tropomyosin complex influences contraction kinetics 221(1)

Thick filaments also influence contractile properties 222(1)

Muscle contraction can generate force 223(1)

Box 5.3 Mathematical Underpinnings Sarcomeric Changes in Force Generation and Shortening 224(1)

Excitation and EC Coupling in Vertebrate Striated Muscle 224(1)

Muscles are excited by an action potential 225(2)

Myogenic muscle cells spontaneously depolarize 227(1)

Neurogenic muscle is excited by neurotransmitters 227(1)

Tonic muscles have multiple innervations 228(1)

T-tubules enhance action potential penetration into the myocyte 228(1)

Ca2+ for contraction comes from intracellular or extracellular stores 228(1)

DHPR activation induces Ca2+ release from the SR 229(1)

Relaxation follows removal of Ca2+ from the cytoplasm 230(2)

Smooth Muscle 232(1)

Smooth muscle lacks organized sarcomeres 232(2)

Smooth muscle contraction is regulated by both thick and thin filament proteins 234(1)

Latch cross-bridges maintain smooth muscle contraction for long periods 234(1)

Muscle Diversity in Vertebrates and Invertebrates 235(12)

Physiological and Developmental Diversity in Vertebrate Striated Muscle 236(1)

Animals make muscles of different fiber types 236(1)

Individuals alter fiber type in response to changing conditions 236(1)

Sonic muscles produce rapid contractions but generate less force 237(1)

Heater organs and electric organs are modified muscles 238(1)

Invertebrate Muscles 239(1)

Invertebrates possess smooth, cross-striated, or obliquely striate muscle 239(1)

Invertebrate muscles contract in response to graded excitatory postsynaptic potentials 240(1)

Asynchronous insect flight muscles do not use Ca2+ transients 241(1)

Mollusc catch muscles maintain contraction for long periods 242(1)

Summary 243(1)

Review Questions 244(1)

Synthesis Questions 245(1)

Quantitative Questions 245(1)

For Further Reading 245(2)

PART TWO INTEGRATING PHYSIOLOGICAL SYSTEMS 247(455)

Sensory Systems 248(58)

Overview 250(1)

General Properties of Sensory Reception 250(7)

Classification of Sensory Receptors 252(1)

Receptors can be classified based on stimulus location or modality 252(1)

Receptors may detect more than one stimulus modality 252(1)

Stimulus Encoding in Sensory Systems 253(1)

Sensory pathways encode stimulus modality 253(1)

Receptive fields provide information about stimulus location 253(2)

Sensory receptors have a dynamic range 255(1)

There is a trade-off between dynamic range and discrimination 256(1)

Range fractionation increases sensory discrimination 256(1)

Sense organs can have a very large dynamic range 256(1)

Many receptors encode signals logarithmically 256(1)

Tonic and phasic receptors encode stimulus duration 257(1)

Chemoreception 257(8)

The Olfactory System 258(1)

The vertebrate olfactory system can distinguish thousands of odorants 258(1)

Odorant receptors are G protein coupled 259(1)

An alternative chemosensory system detects pheromones 260(1)

Invertebrate olfactory mechanisms differ from those in the vertebrates 261(1)

The Gustatory System 261(1)

Taste buds are vertebrate gustatory receptors 262(1)

Vertebrate taste receptors use diverse signal transduction mechanisms 262(2)

Coding differs between the olfactory and gustatory systems 264(1)

Taste reception differs between vertebrates and invertebrates 264(1)

Mechanoreception 265(15)

Touch and Pressure Receptors 266(1)

Vertebrate tactile receptors are widely dispersed 266(1)

Vertebrate proprioceptors monitor body position 267(1)

Insects have several types of tactile and proprioceptors 267(1)

Equilibrium and Hearing 268(1)

Statocysts are the organ of equilibrium for invertebrates 268(1)

Insects use a variety of organs for hearing 269(1)

Vertebrate organs of hearing and equilibrium contain hair cells 270(1)

Tip links are critical for mechanosensory transduction 271(1)

Hair cells are found in the lateral line and ears of fish 271(2)

Vertebrate ears function in hearing and equilibrium 273(1)

The vestibular apparatus is the organ of equilibrium in vertebrates 273(2)

The inner ear detects sounds 275(1)

In terrestrial vertebrates, hearing involves the inner, middle, and outer ears 275(3)

The inner ear of mammals has specializations for sound detection 278(1)

Box 6.1 Evolution and Diversity Electroreception 279(1)

Outer hair cells amplify sounds 280(1)

The ears can detect sound location 280(1)

Photoreception 280(16)

Photoreceptors 281(1)

The structure of photoreceptor cells differs among animals 281(2)

Mammals have two types of photoreceptor cells 283(1)

Chromophores allow photoreceptors to absorb light 284(1)

The mechanisms of phototransduction differ among organisms 284(1)

The Structure and Function of Eyes 285(3)

The structure of the vertebrate eye relates to its function 288(1)

Box 6.2 Genetics and Genomics Molecular Similarity of Diverse Eyes 289(1)

The lens focuses light on the retina 289(2)

Vertebrate retinas have multiple layers 291(1)

Information from rods and cones is processed differently 292(1)

Signal processing in the retina enhances contrast 292(2)

The brain processes the visual signal 294(1)

Color vision requires multiple types of photoreceptors 295(1)

Thermoreception 296(10)

Box 6.3 Evolution and Diversity The Evolution of Trichromatic Color Vision in Primates 297(1)

Magnetoreception 298(1)

Integrating Systems Sensory Systems and Circadian Rhythms 299(2)

Summary 301(2)

Review Questions 303(1)

Synthesis Questions 303(1)

Quantitative Questions 303(1)

For Further Reading 304(2)

Functional Organization of Nervous Systems 306(42)

Overview 308(1)

Organization of Nervous Systems 308(16)

Evolution of Nervous Systems 309(1)

Bilaterally symmetrical animals exhibit cephalization 310(2)

The vertebrate central nervous system is enclosed in a protective covering 312(1)

The cranial and spinal nerves form synapses in the central nervous system 313(1)

The central nervous system is separated from the rest of the body 314(1)

The vertebrate brain has three main regions 314(1)

Brain size and structure vary among vertebrates 315(1)

Structure and Function of the Mammalian Brain 316(1)

The hindbrain supports basic functions 317(1)

The midbrain is greatly reduced in mammals 318(1)

The forebrain controls complex processes 318(1)

The forebrain controls complex processes 318(1)

The hypothalamus maintains homeostasis 319(1)

Box 7.1 Applications Split-Brain Syndrome 320(1)

The limbic system influences emotions 320(1)

The thalamus acts as a relay station 321(1)

The cortex integrates and interprets information 322(2)

The Peripheral Nervous System 324(8)

Autonomic Pathways 324(2)

The sympathetic and parasympathetic branches act together to maintain homeostasis 326(1)

Autonomic pathways share some structural features 327(1)

The anatomy of the sympathetic and parasympathetic branches differ 328(1)

Box 7.2 Applications Receptor Subtype and Drug Design 329(1)

Some effectors receive only sympathetic innervation 330(1)

The central nervous system regulates the autonomic nervous system 330(2)

Somatic Motor Pathways 332(1)

Integrative Functions of Nervous Systems 332(16)

Coordination of Behavior 333(1)

Reflex arcs control many involuntary behaviors 333(1)

Pattern generators initiate rhythmic behaviors 334(1)

Pattern generators govern swimming behavior in the leech 334(1)

Pattern generators and reflexes are involved in tetrapod locomotion 335(1)

The brain coordinates voluntary movements 336(2)

Learning and Memory 338(1)

Invertebrates show simple learning and memory 338(2)

The hippocampus is important for memory formation in mammals 340(2)

Integrating Systems Stress and the Brain 342(2)

Summary 344(1)

Review Questions 345(1)

Synthesis Questions 345(1)

For Further Reading 346(2)

Circulatory Systems 348(62)

Overview 350(1)

Characteristics of Circulatory Systems 350(16)

Components of Circulatory Systems 350(1)

Circulatory systems use diverse pumping structures 351(1)

Circulatory systems can be open or closed 351(1)

Circulatory systems pump several types of fluids 352(1)

Diversity of Circulatory Systems 352(1)

Most annelids have closed circulatory systems 353(1)

Most molluscs have open circulatory systems 354(1)

All arthropods have open circulatory systems 354(2)

Chordates have both open and closed circulatory systems 356(1)

Closed circulatory systems evolved multiple times in animals 356(1)

The Circulatory Plan of Vertebrates 357(1)

Vertebrate blood vessels have complex walls 358(1)

Wall thickness varies among blood vessels 359(1)

Blood vessels undergo angiogenesis 360(1)

Vertebrate circulatory systems contain one or more pumps in series 360(1)

Box 8.1 Genetics and Genomics Angiogenesis 361(1)

Mammals and birds have completely separated pulmonary and systemic circuits 362(1)

Many tetrapods have incompletely separated pulmonary and systemic circuits 362(1)

The Physics of Circulatory Systems 363(1)

The radius of a tube affects its resistance 363(1)

The total flow is constant across all parts of a circulatory system 363(1)

Box 8.2 Mathematical Underpinnings Poiseuille's Equation 364(1)

Velocity of flow is determined by pressure and cross-sectional area 365(1)

Pressure exerts a force on the walls of blood vessels 366(1)

Hearts 366(18)

Box 8.3 Methods and Model Systems Transcription Factors and Heart Development 367(1)

Arthropod Hearts 368(1)

Vertebrate Hearts 368(1)

The myocardium can be spongy or compact 369(1)

Fish heart chambers are arranged in series 370(1)

Amphibian hearts have three chambers 370(1)

Most reptiles have five heart chambers 370(1)

Birds and mammals have four heart chambers 371(1)

Box 8.4 Evolution and Diversity Shunting in Crocodiles 372(1)

The Cardiac Cycle 373(1)

Fish hearts contract in series 373(1)

The mammalian cardiac cycle is similar to that of fishes 374(1)

Some vertebrate hearts fill actively 375(1)

The right and left ventricles develop different pressures 375(1)

Control of Contraction 375(1)

Pacemaker cells initiate the heartbeat 376(1)

The nervous and endocrine systems can modulate the rate of pacemaker potentials 377(1)

Pacemaker depolarizations can spread via gap junctions 378(1)

Cardiac action potentials have an extended depolarization phase 378(1)

Conducting pathways spread the depolarization across the heart 379(1)

The integrated electrical activity of the heart can be detected with the EKG 380(1)

The heart functions as an integrated organ 381(1)

Cardiac output is the product of heart rate and stroke volume 381(1)

The nervous and endocrine systems can modulate stroke volume 382(1)

End-diastolic volume modulates stroke volume 383(1)

Regulation of Pressure and Flow 384(13)

Regulation of Flow 385(1)

The arterioles control blood distribution 385(1)

Myogenic autoregulation maintains blood flow 385(1)

The metabolic activity of the tissue influences blood flow 385(1)

The nervous and endocrine systems regulate arteriolar diameter 386(1)

Regulation of Pressure 387(1)

The arteries dampen pressure fluctuations 388(1)

Mean arterial pressure is determined by systolic and diastolic pressures 389(1)

The skeletal muscle and respiratory pumps aid venous return to the heart 389(1)

The veins act as a volume reservoir 390(1)

Peripheral resistance influences pressure 390(1)

The baroreceptor reflex is the primary means of regulating MAP 391(1)

The kidneys play a major role in maintaining blood volume 392(1)

Blood pressure can force fluid out of the capillaries 392(2)

The lymphatic system returns filtered fluids to the circulatory system 394(1)

Changes in body position can alter blood pressure and flow 395(1)

Changes in body position can cause orthostatic hypotension 396(1)

Blood 397(13)

Composition of Blood 397(1)

Blood contains proteins 397(1)

Blood contains cells 398(1)

Erythrocytes transport oxygen 398(1)

Vertebrate Blood 399(2)

Integrating Systems The Circulatory System

During Exercise 401(2)

Summary 403(3)

Review Questions 406(1)

Synthesis Questions 406(1)

Quantitative Questions 407(1)

For Further Reading 407(3)

Respiratory Systems 410(60)

Overview 412(1)

Respiratory Strategies 413(9)

The Physics of Respiratory Systems 413(1)

Gases exert a pressure 413(1)

Henry's law describes how gases dissolve in liquids 414(1)

Gases diffuse at different rates 415(1)

Fluids flow from areas of high to low pressure 415(1)

Resistance opposes flow 416(1)

Types of Respiratory Systems 416(1)

Very thin animals can rely on diffusion alone for gas exchange 417(1)

Most animals use one of three major respiratory strategies 418(1)

Gas exchange surfaces are often ventilated 419(1)

Perfusion of the respiratory surface affects gas exchange 419(3)

Ventilation and Gas Exchange 422(21)

Ventilation and Gas Exchange in Water 422(1)

Most molluscs ventilate their gills using cilia 423(1)

Crustacean gills are located on the appendages 424(1)

Echinoderms have diverse respiratory structures 424(1)

Feeding lampreys ventilate their gills tidally 425(1)

Elasmobranchs use a buccal pump for ventilation 426(1)

Teleost fishes use a buccal-opercular pump for ventilation 426(2)

Fish gills are arranged for countercurrent flow 428(1)

Ventilation and Gas Exchange in Air 428(1)

Arthropods use a variety of mechanisms for aerial gas exchange 429(1)

Many insects actively ventilate the tracheae 430(2)

Air breathing has evolved multiple times in the vertebrates 432(1)

Amphibians ventilate their lungs using a buccal force pump 433(1)

Reptiles ventilate their lungs using a suction pump 434(1)

Birds unidirectionally ventilate their lungs 435(2)

The alveoli are the site of gas exchange in mammals 437(1)

Box 9.1 Evolution and Diversity Respiratory Strategies of Aquatic Insects 438(1)

Mammals ventilate their lungs tidally 439(1)

The work required for ventilation depends on lung compliance and resistance 440(1)

Surfactants increase lung compliance 440(1)

Airway resistance affects the work required to breathe 441(1)

Aspiration-based pulmonary systems have substantial dead space 441(1)

Pulmonary function tests measure lung function and volumes 442(1)

Ventilation-perfusion matching is important for gas exchange 442(1)

Gas Transport to the Tissues 443(13)

Oxygen Transport 444(1)

There are three main types of respiratory pigments 444(1)

Respiratory pigments have characteristic oxygen equilibrium curves 445(2)

The shapes of oxygen equilibrium curves differ 447(1)

Blood pH and Pco2 can affect oxygen affinity 448(1)

Temperature affects oxygen affinity 449(1)

Organic modulators can affect oxygen affinity 449(1)

Box 9.2 Evolution and Diversity Root-Effect Hemoglobins and Swim Bladders 450(2)

Carbon Dioxide Transport 452(1)

The carbon dioxide equilibrium curve quantifies carbon dioxide transport 453(1)

Blood oxygenation affects CO2 transport 453(1)

Vertebrate red blood cells play a role in CO2 transport 454(1)

The respiratory system can regulate blood pH 455(1)

Regulation of Vertebrate Respiratory Systems 456(14)

Regulation of Ventilation 456(1)

Chemosensory input influences ventilation 457(1)

Other factors regulate breathing 458(1)

Environmental Hypoxia 458(1)

Fish respond to hypoxia in many ways 459(1)

Air breathers can experience high-altitude hypoxia 459(1)

Box 9.3 Evolution and Diversity Hypoxic Metabolic Suppression 460(2)

Integrating Systems The Physiology of Diving 462(2)

Summary 464(2)

Review Questions 466(1)

Synthesis Questions 466(1)

Quantitative Questions 467(1)

For Further Reading 467(3)

Ion and Water Balance 470(56)

Overview 472(1)

Ion and Water Balance 472(24)

Strategies for Ionic and Osmotic Regulation 473(1)

Most aquatic animals regulate ion and water balance to some degree 473(2)

The environment provides water in many forms 475(1)

Box 10.1 Evolution and Diversity Life Without Water 476(2)

Solutes can be classified as perturbing, compatible, or counteracting 478(1)

Cells transport solutes in and out of the extracellular fluid to control cell volume 479(2)

The Role of Epithelial Tissues 481(1)

The integument is an osmotic barrier 481(2)

Epithelial tissues share four specialized properties that affect ion movements 483(1)

Solutes move across epithelial tissues by paracellular and transcellular transport 484(1)

Fish gills transport ions into and out of the water 485(1)

Digestive epithelia mediate ion and water transfers 486(1)

Reptiles and birds possess salt glands 487(1)

Elasmobranch rectal glands excrete Na+ and Cl-, while retaining urea 488(2)

Nitrogen Excretion 490(1)

Ammonia is produced in amino acid metabolism 490(1)

Ammonia can be excreted across epithelial tissues 491(1)

Birds, reptiles, and insects excrete uric acid 491(1)

Urea is produced in the ornithine-urea cycle 492(1)

Each nitrogenous waste strategy has inherent costs 493(1)

Box 10.2 Genetics and Genomics Evolution of the Urea Cycle 494(1)

The mode of nitrogen excretion can change with development or environmental conditions 495(1)

Cartilaginous fish produce urea as an osmolyte 495(1)

The Kidney 496(30)

Kidney Structure and Function 497(1)

The nephron is the functional unit of the kidney 497(1)

Filtration occurs at the glomerulus 498(1)

The primary urine is modified by reabsorption and secretion 499(2)

Cellular properties differ among regions of the tubule 501(1)

The proximal tubule reabsorbs salts and organic metabolites 502(1)

The loop of Henle mediates sequential uptake of water, then salt 503(1)

The distal tubule mediates K+ secretion, NaCl reabsorption, and hormone-sensitive water recovery 504(1)

The collecting duct regulates ion and water flux 504(1)

Nephrons also contribute to acid-base balance 505(1)

The loop of Henle creates a countercurrent multiplier 505(1)

The vasa recta maintains the medullary osmotic gradient via a countercurrent exchanger 506(1)

Micturition is regulated by reflex and higher pathways 506(1)

Regulation of Renal Function 507(1)

Glomerular filtration pressure is affected by hydrostatic pressure and oncotic pressure 507(1)

Box 10.3 Methods and Model Systems Measuring Glomerular Filtration Rate 508(1)

Intrinsic and extrinsic regulators control GFR 509(1)

Vasopressin alters the permeability of the collecting duct 510(1)

Aldosterone regulates sodium and potassium balance 511(2)

The renin-angiotensin-aldosterone pathway regulates blood pressure 513(1)

Natriuretic peptides also play a role in sodium balance 513(1)

Hypothalamic factors regulate thirst 513(1)

Evolutionary Variation in the Structure and Function of Excretory Systems 514(1)

Invertebrates have primitive kidneys called nephridia 514(1)

Insects use Malpighian tubules and the hindgut for ion and water regulation 515(1)

Chondrichthian kidneys produce hyposmotic urine and retain urea 516(1)

The role of the fish kidney differs in freshwater and seawater 517(1)

The amphibian kidney changes in metamorphosis 517(1)

Terrestrial animals have kidneys that help conserve water 518(1)

Integrating Systems Interaction of the Cardiovascular and Excretory Systems in the Regulation of Blood Pressure 519(2)

Summary 521(1)

Review Questions 522(1)

Synthesis Questions 523(1)

Quantitative Questions 523(1)

For Further Reading 523(3)

Digestion 526(46)

Overview 528(1)

The Nature and Acquisition of Nutrients 528(15)

Nutrients 529(1)

Diets provide energy for activity, growth, maintenance, and reproduction 529(1)

Vitamins and minerals participate in catalysis 530(1)

Inadequate supply of essential amino acids compromises growth 531(1)

Animals require linoleic and linolenic acid in the diet 531(1)

Digestion of specific nutrients requires specific enzymes 531(1)

Symbiotic organisms contribute to animal digestive physiology 532(1)

Box 11.1 Evolution and Diversity Chemolithotrophic Symbionts 533(1)

Nutrients move across the plasma membrane via carriers or vesicles 534(1)

Carbohydrates are hydrolyzed in the lumen and transported by multiple carriers 534(1)

Proteins are broken down into amino acids by proteases and peptidases 535(1)

Lipids are transported in many forms 536(1)

Finding and Consuming Food 537(1)

Animals sense food using chemical, electrical, and thermal cues 538(1)

Box 11.2 Applications Animal Diets and Human Health 539(1)

Simple animals digest food within phagocytic vesicles 540(1)

Feeding structures are matched to diet 540(2)

Bird beaks are composed of keratinized tissue 542(1)

Mammals have bony teeth 543(1)

Integrating Digestion with Metabolism 543(29)

Digestive Systems 543(1)

Box 11.3 Genetics and Genomics Variation in Bird Beaks 544(2)

Gut complexity is linked to the appearance of the coelom 546(1)

The digestive systems of complex animals maximize surface area 547(2)

Specialized compartments increase the efficiency of digestion 549(2)

Salivary glands secrete water and digestive enzymes 551(1)

The stomach secretes acid and mucus 551(1)

Most nutrients are absorbed in the intestines 552(2)

Regulating Feeding and Digestion 554(1)

Hormones control the desire to feed 555(1)

Box 11.4 Mathematical Underpinnings Gut Reactor Theory 556(2)

Hormones and neurotransmitters control secretions 558(1)

Gut motility is regulated by nerves and hormones that act on smooth muscle 559(2)

Metabolic transitions between meals 561(1)

Hormones control postprandial regulation of nutrient stores 562(2)

Prolonged food deprivation can trigger a starvation response 564(1)

Pythons rebuild the digestive tract for each meal 565(1)

Dormant bears recycle nitrogen 565(1)

Integrating Systems Obesity 566(2)

Summary 568(1)

Review Questions 569(1)

Synthesis Questions 570(1)

Quantitative Questions 570(1)

For Further Reading 571(1)

Locomotion 572(52)

Overview 574(1)

Locomotor Systems 574(23)

Muscle Fiber Types 574(1)

Many invertebrates use simple circular and longitudinal muscles to move 575(1)

Fish use two or three fiber types to swim 576(1)

The pattern of locomotor muscle contraction is controlled by motor neurons 577(2)

Tetrapods have a multiplicity of fiber types 579(1)

Locomotor muscles are organized into locomotor modules and functional groups 579(1)

Energy Metabolism 580(1)

Glycolysis and mitochondria support different types of locomotion 581(1)

Mitochondrial content influences muscle aerobic capacity 582(1)

Muscle must recover from high-intensity activity 582(1)

Metabolic transitions accompany prolonged exercise 583(2)

Hormones control fuel oxidation in muscle 585(1)

Perfusion and Oxygen Delivery to Muscle 586(1)

Capillary networks bring oxygen to the vertebrate muscle fibers 587(1)

Vasoactive agents regulate blood vessel diameter 588(1)

Myoglobin aids in oxygen delivery and utilization 588(1)

Skeletal Systems 589(1)

Hard skeletons are made from cellular secretions 589(2)

Vertebrate skeletons are composed of mineralized calcium 591(1)

Skeletal components act as mechanical levers 591(2)

Skeletons can store elastic energy 593(1)

Translating Contraction into Movement 594(1)

Muscles are specialized for force generation or shortening velocity 594(1)

Box 12.1 Methods and Model Systems Animal Athletes 595(1)

Work loops show the balance between positive and negative work 596(1)

Moving in the Environment 597(27)

Gravity and Buoyancy 598(1)

Body composition influences buoyant density 598(1)

Lipid stores increase the buoyancy of zooplankton and sharks 598(1)

Swim bladders are gas-filled sacs that increase buoyancy 599(1)

Fluid Mechanics 600(1)

Reynolds numbers determine turbulent or laminar flow 600(1)

The relative importance of viscous and inertial effects determine Re 601(1)

Streamlining reduces drag 602(1)

Aerodynamics and Hydrodynamics 603(1)

Aerofoils and hydrofoils generate lift 603(1)

Soaring uses lift from natural air currents to overcome gravity 604(1)

Box 12.2 Evolution and Diversity The Origins of Flight 605(1)

Fluid movements can generate propulsion 606(1)

Fin and wing shapes influence fluid movements 607(1)

Terrestrial Life 608(1)

Aquatic animals invaded the land several times 608(1)

Metamorphosis remodels anatomy and physiology for terrestrial locomotion 609(1)

Flightless birds evolved in the absence of terrestrial predators 610(1)

Animals of similar geometry should be able to jump to the same heights 610(1)

Terrestrial animals require strong bones and postural musculature 611(1)

Energetics of Movement 612(1)

Energy demands of movement can be expressed as total costs or mass-specific costs 612(1)

Box 12.3 Genetics and Genomics Artificial Selection of House Mice 613(1)

Velocity of movement affects locomotor costs 614(1)

Animals change style of movement to alter the costs of locomotion 614(1)

Environment determines energetic costs 615(1)

Body size affects costs of locomotion 616(2)

Integrating Systems Migration 618(2)

Summary 620(1)

Review Questions 621(1)

Synthesis Questions 621(1)

Quantitative Questions 621(1)

For Further Reading 622(2)

Thermal Physiology 624(38)

Overview 626(1)

Heat Exchange and Thermal Strategies 627(10)

Controlling Heat Fluxes 627(1)

Water has a higher thermal conductivity than air 628(1)

Convective heat exchange depends on fluid movements 629(1)

Radiant energy warms some animals 629(1)

Evaporation induces heat losses 629(1)

Ratio of surface area to volume affects heat flux 630(1)

Insulation reduces thermal exchange 631(1)

Thermal Strategies 631(1)

Poikilotherms and homeotherms differ in the stability of TB 631(1)

Box 13.1 Evolution and Diversity Lions' Manes Are Hot! 632(1)

Ectotherms and endotherms differ in the source of body thermal energy 633(1)

Heterotherms exhibit temporal or regional endothermy 633(1)

Animals have a characteristic degree of thermotolerance 634(3)

Coping with a Changing Body Temperature 637(10)

Macromolecular Structure and Metabolism 637(1)

Animals remodel membranes to maintain near-constant fluidity 637(1)

Box 13.2 Mathematical Underpinnings Evaluating Thermal Effects on Physiological Processes Using Q10 and Arrhenius Plots 638(2)

Temperature changes enzyme kinetics 640(1)

Evolution may lead to changes in enzyme kinetics 641(1)

Ectotherms can remodel tissues in response to long-term changes in temperature 642(1)

Life at High and Low Body Temperatures 642(1)

Some enzymes display cold adaptation 642(1)

Stress proteins are induced at thermal extremes 643(1)

Ice nucleators control ice crystal growth in freeze-tolerant animals 644(1)

Box 13.3 Methods and Model Systems Heat Shock Proteins in Drosophila 645(1)

Antifreeze proteins can prevent intracellular ice formation 646(1)

Maintaining a Constant Body Temperature 647(15)

Thermogenesis 647(1)

Shivering thermogenesis results from unsynchronized muscle contractions 647(1)

Heat is produced in metabolic futile cycles 648(1)

Membrane leakiness enhances thermogenesis 648(1)

Thermogenin enhances mitochondrial proton leak 649(1)

Regulating Body Temperature 650(1)

A central thermostat integrates central and peripheral thermosensory information 650(1)

Piloerection reduces heat losses 651(1)

Changes in blood flow affect thermal exchange 651(1)

Countercurrent exchangers in the vasculature help retain heat 652(1)

Box 13.4 Mathematical Underpinnings Countercurrent Systems 653(1)

Sweating reduces body temperature by evaporative cooling 653(1)

Panting increases heat loss across the respiratory surface 654(1)

Relaxed endothermy results in hypometabolic states 655(1)

Integrating Systems Immune System and Thermoregulation 656(2)

Summary 658(1)

Review Questions 659(1)

Synthesis Questions 660(1)

Quantitative Questions 660(1)

For Further Reading 660(2)

Reproduction 662(40)

Overview 664(1)

Sexual Reproduction 664(33)

Reproductive Hormones 666(1)

Vertebrates rely on progesterone, androgens, and estrogens 666(1)

Gonadotropins control steroid hormone levels 666(2)

JH and 20HE control development and reproductive physiology of arthropods 668(1)

Sex Determination 669(1)

Asexual reproduction occurs by cloning and parthenogenesis 669(1)

Animals may be simultaneous or serial hermaphrodites 670(1)

Sex is determined in some species by environmental conditions 671(1)

Oogenesis 672(1)

The three main modes of reproduction are ovipary, vivipary, and ovovivipary 672(1)

Ova are produced within follicles of somatic tissue 672(1)

The yolk provides building blocks and metabolic precursors 673(1)

Insect eggs are surrounded by a chorion 674(1)

Egg structure differs in aquatic and terrestrial vertebrates 674(1)

Spermatogenesis and Fertilization 675(1)

Leydig cells and Sertoli cells control spermatogenesis 675(1)

Box 14.1 Evolution and Diversity Pheromones 676(2)

Male copulatory organs increase the efficiency of sperm transfer 678(2)

Sperm alter activity in response to chemokinetic and chemotaxic molecules 680(1)

Females use sperm storage to ensure uninterrupted reproduction 680(1)

Individual sperm can compete for the opportunity to fertilize the egg 680(1)

Some animals delay embryonic development 681(1)

Postfertilization development relies on maternal factors 681(1)

Amniotes produce four extraembryonic membranes early in development 682(1)

The Reproductive Cycle of Mammals 682(1)

Hormones control the ovarian and uterine cycles 683(1)

The follicular phase of ovulation is driven by FSH 683(2)

Ovulation and the luteal phase follow an LH surge 685(1)

The endometrial cycle parallels the ovulatory cycle 685(1)

A placenta forms after a fertilized ovum implants in the uterine wall 686(1)

Contractions of uterine smooth muscle induce parturition 687(1)

Milk is a secretory product of mammary glands 688(1)

Mammary gland secretions include two novel products, casein and lactose 689(1)

Prolactin controls parental behavior 690(1)

Box 14.2 Genetics and Genomics Prolactin 691(1)

Integrating Systems Reproduction and Stress 692(2)

Summary 694(1)

Review Questions 695(1)

Synthesis Questions 695(1)

Quantitative Questions 695(1)

For Further Reading 695(2)

Appendices

Appendix A: The International System of Units 697(2)

Appendix B: Logarithms 699(1)

Appendix C: Linear, Exponential, Power, and Allometric Functions 700(2)
Additional References 702(7)
Glossary 709(24)
Animal Index 733(5)
Subject Index 738(16)
Photo Credits 754