How do vertebrates get the oxygen they need, or even manage without it for shorter or longer periods of time? How do they sense oxygen, how do they take it up from water or air, and how do they transport it to their tissues? Respiratory system adaptations allow numerous vertebrates to thrive in extreme environments where oxygen availability is limited or where there is no oxygen at all. Written for students and researchers in comparative physiology, this authoritative summary of vertebrate respiratory physiology begins by exploring the fundamentals of oxygen sensing, uptake and transport in a textbook style. Subsequently, the reader is shown important examples of extreme respiratory performance, like diving and high altitude survival in mammals and birds, air breathing in fish, and those few vertebrates that can survive without any oxygen at all for several months, showing how evolution has solved the problem of life without oxygen.
Author(s): Göran E. Nilsson
Publisher: Cambridge University Press
Year: 2010
Language: English
Pages: 352
Half-title......Page 3
Title......Page 5
Copyright......Page 6
Contents......Page 9
Contributors......Page 11
Preface......Page 13
Abbreviations......Page 15
Part I General Principles......Page 19
1 Introduction: why we need oxygen......Page 21
1.1 Oxygen and cellular energy......Page 23
1.2 The brain: the first organ to suffer......Page 24
1.4 Oxygen-independent ways of making ATP......Page 28
References......Page 30
2.1 Introduction......Page 32
2.2.2 Reactive oxygen species......Page 34
2.2.4 Adenosine and its phosphates......Page 36
2.3.1.1 The globin family of heme proteins......Page 37
2.3.1.2 Cytochromes......Page 40
2.3.2 Prolyl and asparaginyl hydroxylases, and the function of hypoxia-inducible factor......Page 41
2.4 Transduction systems for oxygen effects......Page 46
2.4.1.1 Examples of rapid oxygen-dependent responses in which oxygen sensing plays a primary role: regulation of hemoglobin–oxygen affinity......Page 47
2.4.1.2 Examples of rapid oxygen-dependent responses in which oxygen sensing plays a primary role: regulation of ventilation I......Page 48
2.4.1.3 Examples of rapid oxygen-dependent responses in which oxygen sensing plays a primary role: regulation of ventilation II......Page 51
2.4.2 Oxygen-dependent gene expression......Page 52
References......Page 55
3.1 Introduction......Page 67
3.2 Structure of the gill: integrating design and function......Page 68
3.3 Basic principles of O2 transfer across the gill......Page 72
3.3.1 Gill remodeling and the osmorespiratory compromise......Page 75
3.4 Sensing of the environment and regulation of O2 uptake at the gill......Page 79
3.5 Blood O2 transport......Page 82
3.5.1 Regulation of blood gas transport......Page 85
3.5.2 Interspecific variation in blood gas transport......Page 90
3.6.1 Rainbow trout......Page 96
3.6.2 Starry flounder......Page 98
References......Page 99
4.1 Introduction......Page 113
4.2 General models for O2 uptake and transport......Page 114
4.2.1 The oxygen-transport cascade......Page 115
4.3.1 Overview of lung ventilation in vertebrates......Page 117
4.3.2 Variation in lung structure in vertebrates......Page 118
4.3.3 Ventilation and the composition of lung gases......Page 119
4.3.4 Pulmonary oxygen uptake through diffusion......Page 120
4.3.5 Gas-exchange efficiency......Page 122
4.3.6 Gas-exchange inefficiency (deviation from ideal models)......Page 123
4.3.8 Ventilation/perfusion heterogeneity......Page 125
4.3.9 Hypoxic pulmonary vasoconstriction......Page 127
4.4 Convection of oxygen by the cardiovascular system......Page 129
4.4.1 The role of cardiac shunts......Page 130
4.5 Increased oxygen demand......Page 132
4.6 Phanerozoic Eon and the evolution of the vertebrate oxygen-transport system......Page 138
References......Page 139
Part II Special Cases......Page 147
5.1 Hypoxia in the aquatic environment......Page 149
5.1.2 Critical thresholds......Page 152
5.2 Maintenance of oxygen delivery......Page 157
5.2.2 Gill plasticity in response to hypoxia......Page 159
5.2.3 Ventilatory and circulatory adjustments......Page 161
5.3 Defense of the hypoxic brain......Page 165
5.4 The fish heart in hypoxia......Page 166
5.5 Hematological adaptations to hypoxia......Page 167
5.6 Reducing energy expenditure......Page 171
5.7 Hypoxic tissue damage......Page 174
5.8 Hypoxia tolerance and size......Page 175
References......Page 180
6.2 Oxygen and water......Page 192
6.3.2 Circumstances of air breathing in fishes......Page 194
6.4.1 Phylogeny......Page 196
6.4.2 The paleoatmosphere and air breathing in fishes......Page 197
6.4.3 Diversity of air-breathing fishes......Page 198
6.4.4 The lung and the respiratory gas bladder......Page 199
6.4.5 Lung and gas bladder homology......Page 200
6.4.6 Epithelial complexity......Page 203
6.4.7 Other ABOs: air breathing beyond the respiratory gas bladder......Page 204
5 Case studies of hypoxia and air breathing in fishes......Page 206
6.5.1 Case study 1. Transition to air breathing: the loricariid model......Page 208
6.5.1.1 Behavior, morphology and evolution......Page 209
6.5.1.2 Physiology and biochemistry of air breathing......Page 210
6.5.2.1 Morphology......Page 213
6.5.2.2 Comparative morphology and respiration......Page 214
6.5.2.3 Hypoxia effects......Page 216
6.5.2.4 Estivation......Page 217
6.5.3.1 Gillichthys......Page 220
6.5.3.2 Odontamblyopus......Page 221
6.5.3.3 Mudskippers and their allies......Page 222
6.5.3.4 Hypoxia and mudskippers......Page 224
Appendix A: New findings about air-breathing in fishes......Page 227
Family Mormyridae......Page 228
Family Cichlidae......Page 229
Family Gobiidae......Page 230
References......Page 231
7.1 Introduction......Page 240
7.2 Oxygen stores......Page 241
7.2.2 Spleen storage of RBCs......Page 242
7.2.4 Myoglobin......Page 243
7.3 Respiratory sensitivity to asphyxia......Page 244
7.4 Oxygen economy during experimental and long-duration natural dives......Page 245
7.4.1.2 Heart......Page 247
7.4.1.4 Liver and intestines......Page 248
7.4.1.5 Muscle......Page 249
7.4.1.6 Lung......Page 251
7.4.3 Hypometabolism during diving......Page 252
7.4.4 Body cooling during diving......Page 253
7.4.5 Size matters......Page 254
7.4.7 Protection from respiratory acidosis......Page 255
7.5 Short voluntary dives......Page 256
7.6 Central nervous integration of the physiological responses to diving......Page 258
7.7.1 Enhanced potential for anaerobic metabolism......Page 259
7.7.3 Mechanisms of metabolic arrest......Page 260
7.7.5 Mechanisms of channel arrest......Page 263
7.7.7 Tolerating the consequences of hypoxia: antioxidant defense......Page 264
7.8 Brain function during diving-induced hypoxia......Page 265
7.8.1 The capacity for cerebral anaerobic metabolism in diving animals......Page 267
7.8.2 Cerebral metabolic depression in diving?......Page 268
7.8.3 Neuroglobin as a possible neuroprotective factor in diving mammals......Page 270
References......Page 271
8.2 The high-altitude environment......Page 283
8.3 Vertebrate diversity at high altitude......Page 285
8.3.2 Birds......Page 286
8.4.1 Mammals......Page 287
8.4.1.1 Deer mice......Page 289
8.4.1.2 Fetal llamas......Page 290
8.4.2 Birds......Page 291
8.4.3 Ectotherms......Page 292
8.5.1 Humans climbing to extreme altitude......Page 294
8.5.2 Birds flying over Mount Everest......Page 297
8.6.1.1 Acute mountain sickness......Page 298
8.6.1.2 Highltitude cerebral edema......Page 299
8.6.2.1 High-altitude pulmonary edema......Page 300
8.6.2.3 Ascites in domestic chickens......Page 301
8.6.3.1 Chronic mountain sickness......Page 302
8.7.1 Oxygen conservation......Page 303
8.7.2 Efficient gas exchange in the lung and tissues......Page 304
8.7.3 High hemoglobin-oxygen affinity......Page 305
References......Page 307
9.1 Introduction......Page 318
9.2 Activity level and metabolism in anoxia......Page 321
9.3 Metabolic adaptations: ethanol production or lactate buffering......Page 325
9.4 Brain activity in anoxia......Page 328
9.5.1 Direct sensing of energy deficiency......Page 329
9.5.2 Ion channels......Page 332
9.5.3 Neurotransmitters......Page 335
9.6 Conclusions......Page 338
References......Page 340
Index......Page 347
