Sturkie's Avian Physiology

Sturkie’s Avian Physiology
Copyright
Dedication
Contributors
1. The importance of avian physiology
	1.1 Specific examples of the importance of avian physiology
		1.1.1 Physiology and poultry production
		1.1.2 Physiological ecology and birds, marine, freshwater, and terrestrial
	1.2 Conclusions
	References
2. Avian genomics
	2.1 Introduction
	2.2 Genome
		2.2.1 Size
		2.2.2 Karyotype
	2.3 Genome assemblies
		2.3.1 Chicken legacy genomes
		2.3.2 Future chicken genome assembly
		2.3.3 Genes
		2.3.4 Transposons and endogenous viral elements
		2.3.5 Genome browsers
	2.4 Connecting genome sequence to phenotype
		2.4.1 Connecting genotype to phenotype
		2.4.2 Genome wide association study
		2.4.3 Resequencing
		2.4.4 Annotation
		2.4.5 CRISPR
	2.5 Conclusions
	References
3. Transcriptomic analysis of physiological systems
	3.1 Introduction
	3.2 Early efforts
	3.3 Nervous system
	3.4 Endocrine system
	3.5 Reproductive system
	3.6 Immune system
	3.7 Muscle, liver, adipose, and gastrointestinal tissues
	3.8 Cardiovascular system
	3.9 Hurdles and future developments
	References
4. Avian proteomics
	4.1 Introduction
	4.2 Protein identification and analysis
		4.2.1 Historical to current techniques
	4.3 Quantitative proteomics
	4.4 Structural proteomics
	4.5 Application of proteomics in avian research
		4.5.1 Proteomics of egg physiology, embryonic development, and reproduction
		4.5.2 Proteomics of behavior and plumage
		4.5.3 Proteomics of performance and physiology
		4.5.4 Proteomics of disease, myopathy, and infection
			4.5.4.1 Disease proteomics
			4.5.4.2 Proteomics of muscle myopathy
			4.5.4.3 Proteomics of infections
		4.5.5 Proteomics of avian welfare
	4.6 Conclusions
	References
	Further reading
5. Avian metabolomics
	5.1 Introduction to metabolomics
	5.2 Methods of metabolomics
		5.2.1 Instrumentation
			5.2.1.1 Nuclear magnetic resonance spectroscopy
			5.2.1.2 Mass spectrometry
				5.2.1.2.1 Separation
				5.2.1.2.2 Identification—targeted versus untargeted mass spectrometric analysis
				5.2.1.2.3 Data processing
		5.2.2 Data analysis and interpretation
	5.3 Applications of metabolomics to avian physiology
		5.3.1 Growth and efficiency
		5.3.2 Consequences of selection
			5.3.2.1 Accretion of excess body fat
			5.3.2.2 Muscle myopathies
			5.3.2.3 Ascites syndrome
			5.3.2.4 Heat stress/stress
		5.3.3 Mechanisms of antibiotic growth promoters
		5.3.4 Toxicology
	5.4 Conclusions
	References
6. Mitochondrial physiology—Sturkie's book chapter
	6.1 Overview of mitochondria
		6.1.1 Introduction
		6.1.2 Physical description
		6.1.3 Mitochondrial and nuclear DNA interaction for assembly and function
		6.1.4 The respiratory chain and adenosine triphosphate synthesis
			6.1.4.1 Ubiquinone (coenzyme Q)
			6.1.4.2 Cardiolipin
		6.1.5 Assessing mitochondrial function
			6.1.5.1 Polarographic method
			6.1.5.2 Flux analysis
		6.1.6 Mitochondrial role in apoptosis
	6.2 Mitochondrial inefficiencies, oxidative stress, and antioxidants
		6.2.1 Electron transport defects and oxidative stress
			6.2.1.1 Reactive oxygen species
			6.2.1.2 Identification of site-specific defects in electron transport
			6.2.1.3 Nitric oxide and reactive nitrogen species
			6.2.1.4 DNA damage and respiratory chain complex activities
			6.2.1.5 Specific protein targets of mitochondrial reactive oxygen species
			6.2.1.6 Mitochondrial reactive oxygen species generation in avian species
		6.2.2 Mitochondrial uncoupling and attenuation of oxidative stress
		6.2.3 Antioxidants
	6.3 Signal transduction and reverse electron transport
		6.3.1 Low mitochondrial reactive oxygen species levels
		6.3.2 Cellular nutrient utilization
		6.3.3 Macrophage function
		6.3.4 Ischemia-reperfusion injury
		6.3.5 Muscle differentiation
		6.3.6 Aging and longevity
	6.4 Matching energy production to energy need
		6.4.1 Mitochondrial dynamics
		6.4.2 Mitochondrial biogenesis
		6.4.3 Adenosine monophosphate–activated protein kinase
		6.4.4 Sirtuins
	Acknowledgments
	References
7. Evolution of birds
	7.1 Introduction
	7.2 The dinosaur–bird transition
		7.2.1 Theropod dinosaurs
		7.2.2 Feathers first
		7.2.3 Taking wing
		7.2.4 Archaeopteryx, the first bird?
		7.2.5 Flight in Archaeopteryx
	7.3 The Mesozoic avifauna
		7.3.1 Basal birds
		7.3.2 Enantiornithes: the opposite birds
		7.3.3 Cretaceous Ornithuromorpha: forerunners of modern birds
	7.4 Assembling the modern bird
		7.4.1 Freeing the tail for flight
		7.4.2 Perfecting the wing
		7.4.3 Neuroanatomy
		7.4.4 Respiration and vocalization
		7.4.5 Teeth and beaks
		7.4.6 Digestive system
	7.5 Reproduction and development
		7.5.1 Sexual dimorphism
		7.5.2 Eggs
		7.5.3 Nesting
		7.5.4 Development and growth
	7.6 The rise of modern birds
		7.6.1 The shallow Cretaceous roots of crown birds
		7.6.2 Survival and extinction
		7.6.3 An explosive Paleogene radiation
	7.7 The shape of modern bird diversity
		7.7.1 Palaeognathae
		7.7.2 Galloanserae
		7.7.3 Neoaves
	7.8 The impact of humans on birds
	Acknowledgments
	References
8. Domestication of poultry
	8.1 Introduction
	8.2 Domestication
		8.2.1 Chickens
		8.2.2 Turkeys
		8.2.3 Ducks
		8.2.4 Geese
		8.2.5 Other domesticated birds
	8.3 Conclusions
	References
9. The avian somatosensory system: a comparative view
	9.1 Introduction
	9.2 Body somatosensory primary afferent projections in different species
		9.2.1 Spinal cord
		9.2.2 Brainstem
	9.3 Ascending projections of the dorsal column nuclei
	9.4 Telencephalic projections of thalamic nuclei receiving somatosensory input
	9.5 Somatosensory primary afferent projections from the beak, tongue, and syrinx to the trigeminal column
		9.5.1 The principal sensory trigeminal nucleus
		9.5.2 Nucleus of the descending trigeminal tract
	9.6 Nucleus basorostralis
	9.7 The meeting of the spinal and trigeminal systems
	9.8 The somatosensorimotor system in birds
	9.9 Somatosensory projections to the cerebellum
	9.10 Magnetoreception and the trigeminal system
	9.11 Summary and conclusions
	References
10. Avian vision
	10.1 Introduction
	10.2 What vision does?
	10.3 Variations in avian vision
	10.4 Variations in eyes
	10.5 Bird eyes: function, structure, and variations
		10.5.1 The optical system
			10.5.1.1 Variation in the optical systems of bird eyes
		10.5.2 Vision under water
		10.5.3 The image analysis system
			10.5.3.1 Photoreceptors and visual pigments
			10.5.3.2 Variation in the image analysis systems of bird eyes
			10.5.3.3 Variation in the distribution of receptor types
			10.5.3.4 Variation in the densities of receptor types
	10.6 The visual fields of birds
	10.7 Spatial resolution in birds
	10.8 Contrast sensitivity
	10.9 Closing remarks
	References
11. Avian hearing
	11.1 Introduction: what do birds hear?
	11.2 Outer and middle ear
		11.2.1 No specialized outer ear structures except in owls
		11.2.2 The single-ossicle middle ear
		11.2.3 Internally coupled middle ears
	11.3 Basilar papilla (cochlea)
		11.3.1 General morphology and physiology
		11.3.2 Hair cell types: a remarkable example of evolutionary convergence in birds and mammals
		11.3.3 Hair cell regeneration: birds never lose their hearing
		11.3.4 Cochlear specializations: auditory foveae, infrasound hearing
		11.3.5 Auditory nerve: what the ear conveys to the brain
	11.4 The auditory brain
		11.4.1 Basic organization of auditory pathways
		11.4.2 The generation of an auditory space map in the barn owl
		11.4.3 Developmental plasticity: auditory space is calibrated by vision
		11.4.4 The special processing of birdsong
		11.4.5 Echolocating birds
	11.5 Summary
	References
12. Chemesthesis and olfaction
	12.1 Chemical senses
	12.2 Chemesthesis
	12.3 Neural organization
		12.3.1 Peptides involved in pain perception
		12.3.2 Responses to chemicals
		12.3.3 Structure-activity relationships
		12.3.4 Transient receptor potential channels
	12.4 Olfaction
		12.4.1 Olfactory morphology, neural architecture, and transduction of chemical signals
		12.4.2 Olfactory bulb size, olfactory acuity, and genomics of olfactory receptors
		12.4.3 Laboratory detection thresholds, discrimination, and seasonal change
		12.4.4 Odor detection during development
		12.4.5 How do birds use olfactory cues?
	12.5 Summary
	References
13. Taste in birds
	13.1 Introduction
		13.1.1 What is taste?
		13.1.2 Taste perception
			13.1.2.1 Role of taste
			13.1.2.2 The five taste modalities
		13.1.3 Anatomy of taste buds
			13.1.3.1 Taste buds
			13.1.3.2 Morphology
			13.1.3.3 Types of taste buds
			13.1.3.4 Taste buds markers in chickens
			13.1.3.5 Taste bud number and distribution
				13.1.3.5.1 Distribution in different vertebrates
				13.1.3.5.2 Distribution in birds
			13.1.3.6 Afferent nerves from the taste buds
			13.1.3.7 Changes in taste buds during growth and development
		13.1.4 Taste receptors
			13.1.4.1 Overview
			13.1.4.2 Caveat on taste receptors
			13.1.4.3 Taste receptor type 1 receptors (tas1r family)
		13.1.5 Sweet taste
			13.1.5.1 Overview
			13.1.5.2 Sweet preferences in birds
			13.1.5.3 The sweet dilemma
			13.1.5.4 Evolutionary considerations of Tas1r2
		13.1.6 Umami taste
			13.1.6.1 Overview
			13.1.6.2 Umami preference test in birds
		13.1.7 Taste receptor type 2 receptors
		13.1.8 GPCRs' taste signal transduction
			13.1.8.1 Overview
			13.1.8.2 Sequencing of taste receptor type 2 receptors (TAS2R) in birds
				13.1.8.2.1 TAS2R1 and TAS2R2
				13.1.8.2.2 Other TAS2R genes
				13.1.8.2.3 Evolutionary aspects of taste receptor type 2 receptors
		13.1.9 Bitter taste
			13.1.9.1 Overview
			13.1.9.2 Agonists of bitter receptors (TAS2R)
			13.1.9.3 Ecological influence on bitter taste
		13.1.10 Salt and sour taste
			13.1.10.1 Salt taste receptor in birds
			13.1.10.2 Salty preferences tests
			13.1.10.3 Sour taste receptor in birds
			13.1.10.4 Sour preferences tests
		13.1.11 Fatty acid taste
		13.1.12 Extra gustatory taste in birds
			13.1.12.1 Overview
			13.1.12.2 Gene expression of taste receptors and signaling molecules in extra-gustatory tissues in chicken
			13.1.12.3 Effect of tastants on gene expression
		13.1.13 Measuring taste perception in birds: aversion or preference testing
			13.1.13.1 Methods for taste perception tests
			13.1.13.2 Preference tests in birds
			13.1.13.3 In vivo versus in vitro thresholds
		13.1.14 Conclusions
	References
14. Avian nociception and pain
	14.1 Introduction
		14.1.1 What is pain and what is it for?
		14.1.2 Why does pain matter?
	14.2 What evidence is required to demonstrate the capacity for pain?
		14.2.1 What is needed for nociception?
			14.2.1.1 Transduction, transmission, and modulation of nociceptive information
			14.2.1.2 Nocifensive responses
		14.2.2 What is needed for pain?
			14.2.2.1 Higher brain processing of nociceptive inputs
			14.2.2.2 Complex behavioral responses
	14.3 Conclusions
	References
15. Magnetoreception in birds and its use for long-distance migration
	15.1 Introduction
	15.2 Magnetic fields
	15.3 The Earth's magnetic field
	15.4 Changing magnetic fields for experimental purposes
	15.5 Birds use information from the Earth's magnetic field for various behaviors
		15.5.1 Orientation and navigation
	15.6 The magnetic compass of birds
	15.7 Do birds possess a magnetic map?
	15.8 Interactions with other cues
	15.9 How do birds sense the Earth's magnetic field?
	15.10 The induction hypothesis
	15.11 The magnetic-particle–based hypothesis
	15.12 The light-dependent hypothesis
	15.13 Irreproducible results and the urgent need for independent replication
	15.14 Where do we go from here?
	References
16. The avian subpallium and autonomic nervous system
	16.1 Introduction
	16.2 Components of the subpallium
		16.2.1 Dorsal somatomotor basal ganglia
			16.2.1.1 Structures
			16.2.1.2 Functions
		16.2.2 Ventral viscerolimbic basal ganglia
			16.2.2.1 Structures
			16.2.2.2 Functions
		16.2.3 Extended amygdaloid complex: central extended amygdala and medial extended amygdala
			16.2.3.1 Central extended amygdala
				16.2.3.1.1 Structures
				16.2.3.1.2 Functions
			16.2.3.2 Medial extended amygdala
				16.2.3.2.1 Structures
				16.2.3.2.2 Functions
		16.2.4 Basal telencephalic cholinergic and noncholinergic corticopetal system
			16.2.4.1 Structures
			16.2.4.2 Functions
		16.2.5 Septum and septal neuroendocrine systems
			16.2.5.1 Divisions and structures
				16.2.5.1.1 Lateral septal division
				16.2.5.1.2 Medial septal division
				16.2.5.1.3 Septohippocampal septal division
				16.2.5.1.4 Caudocentral septal division
			16.2.5.2 Functions
				16.2.5.2.1 Septal-hypothalamic-pituitary-gonadal neuroendocrine system
				16.2.5.2.2 Septal-hypothalamic-pituitary-adrenal neuroendocrine system
				16.2.5.2.3 Other functions related to structures within the septum
		16.2.6 Preoptic area
			16.2.6.1 Structures
			16.2.6.2 Functions
	16.3 Components of the autonomic nervous system
		16.3.1 Sympathetic nervous system
		16.3.2 Parasympathetic nervous system
	16.4 Integration of the subpallium and ANS in complex neural circuits in birds: two examples involving vasoactive intestinal pol ...
		16.4.1 The social behavior network
		16.4.2 Poikilostasis or shifts in homeostasis: an hypothesis involving the visceral forebrain system
			16.4.2.1 Regulation of annual cycles of avian species
			16.4.2.2 Some current metabolic and behavioral issues with breeding stock of broilers and turkeys
	16.5 Summary and conclusions
	Acknowledgments
	References
	Further reading
17. Blood
	17.1 Introduction
	17.2 Plasma
		17.2.1 Circulating electrolytes
		17.2.2 Circulating nutrients and other small organic molecules
			17.2.2.1 Plasma concentrations of glucose
			17.2.2.2 Plasma concentrations of fatty acids
			17.2.2.3 Plasma concentrations of lactate
			17.2.2.4 Uric acid and urea
			17.2.2.5 Circulating antioxidants
			17.2.2.6 Carotenoids
		17.2.3 Plasma proteins
			17.2.3.1 Extracellular fluid
			17.2.3.2 Albumin
			17.2.3.3 Globulins
			17.2.3.4 Specific proteins including vitamin and cation binding proteins
				17.2.3.4.1 Ceruloplasmin
				17.2.3.4.2 Retinol-binding protein
				17.2.3.4.3 Transferrin
				17.2.3.4.4 Proteins protecting against tissue damage from hemoglobin
				17.2.3.4.5 Hormone binding proteins
				17.2.3.4.6 Sex hormone–binding protein
				17.2.3.4.7 Thyroid hormones/transthyretin
				17.2.3.4.8 Transcortin (corticosteroid bonding globulin)
			17.2.3.5 Gamma globulins
			17.2.3.6 Enzymes
			17.2.3.7 Yolk precursors
	17.3 Erythrocytes
		17.3.1 Structure of the erythrocyte
			17.3.1.1 Nucleus
			17.3.1.2 Plasma and nuclear membranes
				17.3.1.2.1 Lipid composition
				17.3.1.2.2 Carbohydrates in the erythrocyte plasma membrane
				17.3.1.2.3 Proteins in the erythrocyte plasma membrane
			17.3.1.3 Microtubules
			17.3.1.4 Mitochondria
		17.3.2 Erythrocyte chromatin and transcription
			17.3.2.1 Transcription and translation
			17.3.2.2 Stress and erythrocyte DNA
			17.3.2.3 Telomeres
		17.3.3 Metabolism of erythrocytes
			17.3.3.1 Mitochondrial functioning in avian erythrocytes
			17.3.3.2 Enzymes in erythrocytes
		17.3.4 Number of avian erythrocytes and packed cell volume
		17.3.5 Production
		17.3.6 Erythropoietin
		17.3.7 Lifespan
		17.3.8 Hemoglobin
			17.3.8.1 Hemoglobin genes
			17.3.8.2 Adaptations of hemoglobin to flight at high altitudes
			17.3.8.3 Glycation of hemoglobin
			17.3.8.4 Hemoglobin and nutrition
		17.3.9 Carbonic anhydrase
			17.3.9.1 Intracellular pH
		17.3.10 Transporters in erythrocyte plasma membrane
			17.3.10.1 Anion transporter
			17.3.10.2 Sodium and potassium transport
		17.3.11 Glucose
			17.3.11.1 Amino acids and urea
		17.3.12 Hormonal effect on erythrocytes
		17.3.13 Effect of stressors of erythrocytes
		17.3.14 Avian erythrocytes and the innate immune system
	17.4 Blood gases
	17.5 Leukocytes
		17.5.1 Number of leukocytes
		17.5.2 Heterophils
			17.5.2.1 Structure
			17.5.2.2 Function
				17.5.2.2.1 Heterophils and phagocytosis
				17.5.2.2.2 Heterophils and cytokines
				17.5.2.2.3 Heterophils and antimicrobial peptides
				17.5.2.2.4 Toll-like receptors and heterophils
				17.5.2.2.5 Stressors and heterophil functioning
			17.5.2.3 Number
			17.5.2.4 Production
		17.5.3 Lymphocytes
			17.5.3.1 Structure
			17.5.3.2 Function
			17.5.3.3 Numbers
		17.5.4 Eosinophils
			17.5.4.1 Structure
			17.5.4.2 Function
			17.5.4.3 Number
		17.5.5 Monocytes
			17.5.5.1 Structure
			17.5.5.2 Function
			17.5.5.3 Number
			17.5.5.4 Production
		17.5.6 Basophils
			17.5.6.1 Structure
			17.5.6.2 Function
			17.5.6.3 Number
		17.5.7 Heterophil: lymphocyte ratios
	17.6 Thrombocytes
		17.6.1 Structure
		17.6.2 Function
		17.6.3 Number
		17.6.4 Production
		17.6.5 Thrombopoietin
	17.7 Other cells types in avian plasma
		17.7.1 Reticulocytes
		17.7.2 Mott cells
		17.7.3 Natural killer cells
	17.8 Parasites and blood cells
	17.9 Clotting
	References
	Further reading
18. The cardiovascular system
	18.1 Introduction
	18.2 Heart
		18.2.1 Gross structure and function
			18.2.1.1 Functional anatomy
			18.2.1.2 Heart size
			18.2.1.3 Cardiac chambers
			18.2.1.4 Valves
			18.2.1.5 Coronary circulation
		18.2.2 Cardiac variables
		18.2.3 Fine structure and cardiac electrophysiology
			18.2.3.1 Fine structure
			18.2.3.2 Excitation–contraction coupling
			18.2.3.3 Conduction system
			18.2.3.4 Electrophysiology
	18.3 General circulatory hemodynamics
	18.4 The vascular tree
		18.4.1 Arterial system
			18.4.1.1 Gross anatomy
			18.4.1.2 Functional morphology of the arterial wall
			18.4.1.3 Relationship between arterial pressure and flow
		18.4.2 Capillary beds
			18.4.2.1 Gas exchange
			18.4.2.2 Microvascular fluid exchange
			18.4.2.3 Distribution of blood flow at rest
		18.4.3 Venous system
			18.4.3.1 Functional development of venous system
			18.4.3.2 Capacitance function
			18.4.3.3 Physiological role of veins in exercise and submersion
			18.4.3.4 Renal portal system
		18.4.4 Embryonic shunts
	18.5 Control of the cardiovascular system
		18.5.1 Control systems
		18.5.2 Control of peripheral blood flow
			18.5.2.1 Mechanism of vascular reactivity
			18.5.2.2 Autoregulation
			18.5.2.3 Humoral factors
				18.5.2.3.1 Chemical factors
				18.5.2.3.2 Locally released vasoactive agents
				18.5.2.3.3 Circulating agents
			18.5.2.4 Neural control
				18.5.2.4.1 Systemic arterial innervation
				18.5.2.4.2 Systemic venous innervation
				18.5.2.4.3 Pulmonary vessel innervation
				18.5.2.4.4 Autonomic pathways
		18.5.3 Control of the heart
			18.5.3.1 Catecholamine effects on the heart
			18.5.3.2 Neural control
				18.5.3.2.1 Sympathetic innervation
					18.5.3.2.1.1 Anatomy
					18.5.3.2.1.2 Sympathetic control
				18.5.3.2.2 Parasympathetic innervation
					18.5.3.2.2.1 Anatomy
					18.5.3.2.2.2 Parasympathetic control
						18.5.3.2.2.2.1 Dromotropic effects
						18.5.3.2.2.2.2 Chronotropic effects
						18.5.3.2.2.2.3 Inotropic effects
						18.5.3.2.2.2.4 Tonic parasympathetic activity
				18.5.3.2.3 Control of CO
					18.5.3.2.3.1 Role of heart rate in control of CO
					18.5.3.2.3.2 Role of stroke volume in control of CO
		18.5.4 Reflexes controlling the circulation
			18.5.4.1 Chemoreflexes
			18.5.4.2 Baroreflexes
			18.5.4.3 Reflexes from cardiac receptors
			18.5.4.4 Reflex cardiovascular effects from skeletal muscle afferents
		18.5.5 Integrative neural control
		18.5.6 Development of cardiovascular control
			18.5.6.1 Ontogeny of autonomic nervous system control of the heart
				18.5.6.1.1 Cardiac autonomic innervation
				18.5.6.1.2 Cardiac cholinergic and adrenergic receptors
			18.5.6.2 Ontogeny of vascular contractility
				18.5.6.2.1 Vascular reactivity regulation
				18.5.6.2.2 Vascular adrenergic receptors
				18.5.6.2.3 Vascular cholinergic receptors and endothelial control
			18.5.6.3 Developmental integration of autonomic cardiovascular regulation
				18.5.6.3.1 Afferent pathways
				18.5.6.3.2 Tonic heart regulation
				18.5.6.3.3 Tonic vasculature regulation
				18.5.6.3.4 Baroreflex regulation
				18.5.6.3.5 Cardiovascular response to hypoxia
			18.5.6.4 Development of humoral and local effectors of cardiovascular function
	18.6 Environmental cardiovascular physiology
		18.6.1 Flight
			18.6.1.1 Altitude
			18.6.1.2 Migration
		18.6.2 Swimming and diving
	References
19. Renal and extrarenal regulation of body fluid composition
	19.1 Introduction
	19.2 Intake of water and solutes
		19.2.1 Drinking
		19.2.2 Solute intake
	19.3 The kidneys
		19.3.1 Anatomy
			19.3.1.1 Gross anatomy
			19.3.1.2 Nephron types and numbers
			19.3.1.3 Blood flow
				19.3.1.3.1 Arterial supply
				19.3.1.3.2 Renal portal system
				19.3.1.3.3 Venous drainage
		19.3.2 Physiology
			19.3.2.1 Overview
			19.3.2.2 Renal blood flow
			19.3.2.3 Glomerular filtration
			19.3.2.4 Regulation of water excretion
				19.3.2.4.1 Arginine vasotocin
				19.3.2.4.2 Regulation of glomerular filtration rate
				19.3.2.4.3 Tubular water reabsorption and the urinary concentrating mechanism
					19.3.2.4.3.1 Descending thin limb
					19.3.2.4.3.2 Thick ascending limb
					19.3.2.4.3.3 Collecting duct
					19.3.2.4.3.4 Urinary concentrating mechanism
					19.3.2.4.3.5 Net effect: avian urinary concentrating ability
			19.3.2.5 Regulation of sodium excretion
				19.3.2.5.1 Patterns of response
				19.3.2.5.2 Mechanisms of regulation
					19.3.2.5.2.1 Arginine vasotocin
					19.3.2.5.2.2 Renin/angiotensin
					19.3.2.5.2.3 Aldosterone
					19.3.2.5.2.4 Atrial natriuretic peptide
			19.3.2.6 Regulation of calcium and phosphate excretion
				19.3.2.6.1 Calcium
				19.3.2.6.2 Phosphate
			19.3.2.7 Nitrogen excretion
			19.3.2.8 Renal contribution to acid/base regulation
			19.3.2.9 Molecular regulation: the next frontier
			19.3.2.10 The final urine-composition and flow
			19.3.2.11 Function of the ureters
	19.4 Extrarenal organs of osmoregulation: introduction
	19.5 The lower intestine
		19.5.1 Introduction
		19.5.2 Transport properties of coprodeum, colon, and cecum
			19.5.2.1 Basic transport mechanisms in coprodeum and colon
				19.5.2.1.1 Transport of NaCl and water
				19.5.2.1.2 Transport of other ions
				19.5.2.1.3 Quantitative role of coprodeum versus colon
			19.5.2.2 Dietary and hormonal regulation of coprodeal and colonic transport
			19.5.2.3 Ultrastructural adaptation and molecular induction
			19.5.2.4 Salt and water transport in the caeca
		19.5.3 Postrenal modification of ureteral urine
			19.5.3.1 Basic patterns: Hydration/NaCl loading
			19.5.3.2 Basic patterns: Dehydration/NaCl depletion
			19.5.3.3 Special case: birds with salt glands
			19.5.3.4 Special case: the ratites
			19.5.3.5 Quantitative role of the caeca in osmoregulation
			19.5.3.6 Overall: integration of kidneys and lower intestine
	19.6 Salt glands
		19.6.1 Anatomy
		19.6.2 Function
			19.6.2.1 Stimulus for secretion
			19.6.2.2 Secretion mechanism and fluid composition
			19.6.2.3 Regulatory mediators
		19.6.3 Contribution of the salt glands to osmoregulation
	19.7 Evaporative water loss
	Acknowledgments
	References
20. Respiration
	20.1 Overview
		20.1.1 Oxygen cascade
		20.1.2 Symbols and units
	20.2 Anatomy of the avian respiratory system
		20.2.1 Upper airways
		20.2.2 Lungs
			20.2.2.1 Conducting airways
			20.2.2.2 Parabronchi
			20.2.2.3 Frontiers: evolution of the blood-gas barrier
		20.2.3 Air sacs
		20.2.4 Respiratory system volumes
	20.3 Ventilation and respiratory mechanics
		20.3.1 Respiratory muscles
		20.3.2 Mechanical properties
			20.3.2.1 Compliance
			20.3.2.2 Resistance
			20.3.2.3 Air capillary surface forces
		20.3.3 Ventilatory flow patterns
			20.3.3.1 Air sac ventilation
			20.3.3.2 Pulmonary ventilation
			20.3.3.3 Air sac PO2 and PCO2
			20.3.3.4 Effective parabronchial ventilation
			20.3.3.5 Artificial ventilation
			20.3.3.6 Frontiers: lung structure-function in dinosaurs
	20.4 Pulmonary circulation
		20.4.1 Anatomy of the pulmonary circulation
		20.4.2 Pulmonary capillary volume
		20.4.3 Pulmonary vascular pressures, resistance, and flow
			20.4.3.1 Pulmonary vascular resistance and pressures
			20.4.3.2 Distribution of blood flow
			20.4.3.3 Frontiers: pulmonary vascular pressures during exercise in birds
		20.4.4 Fluid balance
	20.5 Gas transport by blood
		20.5.1 Oxygen
			20.5.1.1 Hemoglobin
			20.5.1.2 O2-blood equilibrium curves
			20.5.1.3 Physiological control of O2-hemoglobin affinity
			20.5.1.4 Frontiers: hemoglobin adaptations to high altitude
			20.5.1.5 Factors affecting O2 capacity
		20.5.2 Carbon dioxide
			20.5.2.1 Forms of CO2 in blood
			20.5.2.2 Factors affecting blood-CO2 equilibrium curves
		20.5.3 Acid-base
			20.5.3.1 Henderson-Hasselbalch equation
		20.5.4 Blood gas measurements
	20.6 Pulmonary gas exchange
		20.6.1 Basic principles of oxygen transport
			20.6.1.1 Convection
			20.6.1.2 Diffusion
		20.6.2 Cross-current gas exchange
			20.6.2.1 Cross-current O2 exchange
			20.6.2.2 Cross-current CO2 exchange
		20.6.3 Lung diffusing capacity
			20.6.3.1 Gas transport in air capillaries
			20.6.3.2 Blood-gas barrier diffusion
			20.6.3.3 O2-hemoglobin reaction rates
			20.6.3.4 Physiological estimates of DLO2
		20.6.4 Heterogeneity in the lung
			20.6.4.1 Physiological dead space
			20.6.4.2 Shunt
			20.6.4.3 V./Q. mismatching
			20.6.4.4 Temporal heterogeneity
		20.6.5 Frontiers: pulmonary gas exchange during high altitude flight
	20.7 Tissue gas exchange
		20.7.1 Microcirculation
			20.7.1.1 Skeletal muscle
			20.7.1.2 Cerebral circulation
		20.7.2 Myoglobin
		20.7.3 Effects of hypoxia and exercise
	20.8 Control of breathing
		20.8.1 Respiratory rhythm generation
		20.8.2 Sensory inputs
			20.8.2.1 Central chemoreceptors
			20.8.2.2 Arterial chemoreceptors
				20.8.2.2.1 Intrapulmonary chemoreceptors
			20.8.2.3 Other receptors affecting breathing
		20.8.3 Ventilatory reflexes
			20.8.3.1 CO2 response
			20.8.3.2 Hypoxic ventilatory response
			20.8.3.3 Ventilatory response to exercise
			20.8.3.4 Frontiers: extreme hyperventilation at high altitude
	20.9 Defense systems in avian lungs
	References
21. Gastrointestinal anatomy and physiology
	21.1 Anatomy of the digestive tract
		21.1.1 Beak, mouth, and pharynx
		21.1.2 Esophagus and crop
		21.1.3 Stomach
		21.1.4 Small intestine
		21.1.5 Ceca
		21.1.6 Colon (rectum) and cloaca
	21.2 Anatomy of the accessory organs
		21.2.1 Pancreas
		21.2.2 Liver
	21.3 Motility
		21.3.1 Esophagus
		21.3.2 Gastrointestinal cycle
		21.3.3 Small intestine
		21.3.4 Ceca
		21.3.5 Colon
		21.3.6 Other influences on motility
	21.4 Neural and hormonal control of motility
		21.4.1 Rate of passage
	21.5 Secretion and digestion
		21.5.1 Mouth
		21.5.2 Esophagus and crop
		21.5.3 Stomach
		21.5.4 Intestines
		21.5.5 Colon
		21.5.6 Pancreas
		21.5.7 Bile
	21.6 Absorption
		21.6.1 Carbohydrates
		21.6.2 Amino acid and peptides
		21.6.3 Fatty acids and bile acids
		21.6.4 Volatile fatty acids
		21.6.5 Calcium and phosphorus
		21.6.6 Potassium and magnesium
		21.6.7 Water, sodium, and chloride
		21.6.8 Vitamins
	21.7 Age-related effects on gastrointestinal function
	21.8 Gastrointestinal microbiota
	21.9 Intestinal barrier
	References
22. Avian bone physiology and poultry bone disorders
	22.1 Introduction
	22.2 Embryonic skeletal differentiation
	22.3 Cartilage
		22.3.1 Cartilage of endochondral bone
		22.3.2 Articular cartilage
	22.4 Bone
		22.4.1 Cellular components
		22.4.2 Bone tissue
	22.5 Poultry bone disorders
		22.5.1 Cage layer fatigue/osteoporosis
		22.5.2 Keel bone deformity and fracture
		22.5.3 Cervical scoliosis
		22.5.4 Chondrodystrophy, slipped tendon/perosis, and rickets
		22.5.5 Valgus-varus deformity
		22.5.6 Tibial dyschondroplasia
		22.5.7 Femoral head separation
		22.5.8 Femoral head necrosis, osteomyelitis, bacterial chondronecrosis
		22.5.9 Amyloid arthropathy
	22.6 Conclusion
	References
23. Skeletal muscle
	23.1 Introduction
	23.2 Diversity of avian skeletal muscle
	23.3 Muscle structure and contraction
	23.4 Skeletal muscle fiber types
	23.5 Embryonic development of skeletal muscle
	23.6 Postnatal or posthatch skeletal muscle development
	23.7 Muscle development: function of myogenic regulatory factors
	23.8 Growth factors affecting skeletal muscle myogenesis
	23.9 Satellite cells and myoblast heterogeneity
	23.10 Novel genes involved in avian myogenesis
	23.11 Recent emerging breast muscle necrotic and fibrotic myopathies
	23.12 The effect of fibrillar collagen on the phnotype of necrotic breast muscle myopathies resulting in fibrosis
	23.13 Relationship of fibrillar collagen organization to the phnotype of breast muscle necrotic/fibrotic myopathies
	23.14 Regulation of muscle growth properties by cell-membrane associated extracellular matrix macromolecules
	23.15 Strategies to reduce myopathies
	23.16 Summary
	Acknowledgments
	References
	Further reading
24. Immunophysiology of the avian immune system
	24.1 Introduction
	24.2 Innate immune system recognition, sensing, and function
		24.2.1 Innate cell receptors: pattern recognition receptors
			24.2.1.1 Toll-like receptors
			24.2.1.2 Nod-like receptors
			24.2.1.3 RIG-like receptors
			24.2.1.4 C-type lectin receptors
		24.2.2 Host defense peptides
		24.2.3 Innate immune memory: trained immunity
	24.3 Acquired immune recognition and function
		24.3.1 The major histocompatibility complex
		24.3.2 Th1/Th2 paradigm and T helper cell subsets
	24.4 Gastrointestinal tract and immune system of poultry
		24.4.1 Mucosal lymphoid tissues and cells
		24.4.2 Intestinal barrier system
		24.4.3 Intestinal microbiota
		24.4.4 Intestinal immune functionality
			24.4.4.1 Gut microbiota-immunity communication
				24.4.4.1.1 Components of the microbiota
				24.4.4.1.2 Microbial metabolites
				24.4.4.1.3 Microbial epigenetic modifications
		24.4.5 Gut microbiota: immune homeostasis
			24.4.5.1 Gut microbiota: immune dysfunction—dysbiosis
			24.4.5.2 Gut microbiota: immune dysfunction—inflammation
				24.4.5.2.1 Inflammatory phenotypes
			24.4.5.3 Induction of inflammatory phenotypes
				24.4.5.3.1 Physiological inflammation
				24.4.5.3.2 Pathological inflammation
				24.4.5.3.3 Sterile inflammation
				24.4.5.3.4 Metabolic inflammation
	24.5 Tissue immunometabolism: tissue homeostasis and tissue resident immune cells
	References
25. Carbohydrate metabolism
	25.1 Overview of carbohydrate metabolism in birds
		25.1.1 Introduction
	25.2 Carbohydrate chains in glycoproteins
		25.2.1 Glucose
			25.2.1.1 Circulating concentrations of glucose across avian species
				25.2.1.1.1 Introduction: circulating concentrations of glucose across avian species
				25.2.1.1.2 Domestication and circulating concentrations of glucose
				25.2.1.1.3 Fasting and circulating concentrations of glucose
				25.2.1.1.4 Influence of feeding
				25.2.1.1.5 Shifts in circulating concentration with age, reproductive state, and migration
				25.2.1.1.6 Shifts in circulating concentrations of glucose due to disease, toxicants, and husbandry practices
				25.2.1.1.7 Temperature and circulating concentrations of glucose
				25.2.1.1.8 Issues with the circulating concentrations of glucose
			25.2.1.2 Glucose concentrations in the cerebrospinal fluid
			25.2.1.3 Glucose concentrations in muscle
	25.3 Lactate and pyruvate
		25.3.1 Introduction
		25.3.2 Circulating concentrations of lactate and pyruvate
		25.3.3 Muscle concentrations of lactate
	25.4 Glycerol
		25.4.1 Introduction
		25.4.2 Circulating concentrations of glycerol
	25.5 Glycogen
		25.5.1 Introduction
		25.5.2 Synthesis and breakdown
			25.5.2.1 Glycogenesis (synthesis)
				25.5.2.1.1 Phosphoglucomutase
				25.5.2.1.2 Uridine triphosphate-glucose pyrophosphorylase
				25.5.2.1.3 Glycogen synthase
		25.5.3 Glycogenolysis (breakdown)
			25.5.3.1 Glycogen phosphorylase
			25.5.3.2 Glycogenesis (breakdown)
		25.5.4 What is the concentration of glycogen in avian hepatocytes?
		25.5.5 Hepatic concentrations of glycogen
			25.5.5.1 Overview
			25.5.5.2 Effects of nutrition
			25.5.5.3 Developmental changes
			25.5.5.4 Effects of perihatch nutrition
			25.5.5.5 Developmental changes in glycogenesis
			25.5.5.6 Other effects on hepatic glycogen
			25.5.5.7 Muscle concentrations of glycogen
				25.5.5.7.1 Overview
				25.5.5.7.2 Developmental changes
				25.5.5.7.3 Effects of perihatch nutrition
		25.5.6 Issues with determination of tissue concentrations of glycogen and lactate
		25.5.7 Glycolytic potential
		25.5.8 Glycogen body
	25.6 Glucose and fructose utilization
		25.6.1 Developmental changes
		25.6.2 Fasting and glucose utilization
	25.7 Glucose transporters
		25.7.1 Introduction to avian glucose transporters
		25.7.2 Insulin-dependent glucose transporters
		25.7.3 Tissue expression of glucose transporters
		25.7.4 Physiological control of glucose transporters
	25.8 Intermediary metabolism
		25.8.1 Glucose phosphorylation and dephosphorylation
			25.8.1.1 Glucose phosphorylation to glucose 6-phosphate
				25.8.1.1.1 Enzyme: glucokinase/hexokinase
			25.8.1.2 Glucose 6-phosphatase
		25.8.2 Glycolysis
			25.8.2.1 Developmental changes
			25.8.2.2 Physiological effects
			25.8.2.3 Erythrocytes
			25.8.2.4 Lactate dehydrogenase
		25.8.3 Citric acid or tricarboxylic acid cycle
			25.8.3.1 Overview
			25.8.3.2 Erythrocytes
	25.9 Gluconeogenesis
		25.9.1 Gluconeogenesis and fasting
		25.9.2 Relative importance of the liver and the kidney
	25.10 Carbohydrate digestion and absorption
		25.10.1 Starch digestion
		25.10.2 Disaccharide digestion
			25.10.2.1 Maltose
			25.10.2.2 Sucrose
			25.10.2.3 Lactose
		25.10.3 Glucose absorption
			25.10.3.1 Overview
			25.10.3.2 Noncarrier uptake of glucose
		25.10.4 Glucose digestion in frugivorous birds
		25.10.5 Gastrointestinal storage of ingesta
		25.10.6 Intestinal fermentation
			25.10.6.1 Cellulose
				25.10.6.1.1 Foregut
				25.10.6.1.2 Hindgut
			25.10.6.2 Starch
	25.11 Putative roles of other monosaccharides
		25.11.1 Sorbitol
		25.11.2 Xylitol
	25.12 Conclusions
		25.12.1 Overview
		25.12.2 Starvation and metabolism
	References
	Further reading
26. Adipose tissue and lipid metabolism
	26.1 Introduction
	26.2 Development of adipose tissue
	26.3 Structure, cellularity
	26.4 Body composition
	26.5 Functions of adipose tissue
		26.5.1 Energy reservoir
		26.5.2 Adipokines
			26.5.2.1 Leptin
			26.5.2.2 Adiponectin
			26.5.2.3 Visfatin
			26.5.2.4 Chemerin
			26.5.2.5 Other adipokines
		26.5.3 Receptors
	26.6 Lipid metabolism
		26.6.1 Lipogenesis and lipolysis
		26.6.2 Lipoprotein metabolism
			26.6.2.1 Portomicrons
			26.6.2.2 Other lipoproteins
			26.6.2.3 Lipoprotein lipase: a key enzyme
			26.6.2.4 Lipoproteins in laying hens
		26.6.3 Endocrine control of lipid metabolism
			26.6.3.1 Insulin
			26.6.3.2 Somatotrophic hormones
			26.6.3.3 Thyroid hormones
			26.6.3.4 Other hormones
		26.6.4 Transcription factors
	26.7 Factors affecting fat metabolism and deposition
		26.7.1 Dietary factors
			26.7.1.1 Quantitative strategies
			26.7.1.2 Qualitative strategies
		26.7.2 Genetics
	26.8 Summary and conclusions
	References
27. Protein metabolism
	27.1 Introduction
		27.1.1 Protein metabolism: overview
		27.1.2 Physiological effects on protein concentrations
		27.1.3 Amino acids and proteins
		27.1.4 Posttranslational modification of amino acids
	27.2 Major proteins
		27.2.1 Collagen
			27.2.1.1 Overview
			27.2.1.2 Quantitative aspects
			27.2.1.3 Chemistry of collagen
			27.2.1.4 Functions of collagen
			27.2.1.5 Control of collagen synthesis
		27.2.2 Keratins
			27.2.2.1 Overview
			27.2.2.2 Keratin genes
			27.2.2.3 Keratin expression and protein
			27.2.2.4 Feather dynamics
			27.2.2.5 Control of keratin synthesis
	27.3 Muscle proteins
		27.3.1 Overview
		27.3.2 Actin and myosin genes
	27.4 Other proteins
		27.4.1 Blood proteins
		27.4.2 Mucins
		27.4.3 Egg protein
	27.5 Digestion of proteins
		27.5.1 Overview
		27.5.2 Protein digestion in the gizzard and proventriculus
			27.5.2.1 Overview
			27.5.2.2 Pepsinogen
		27.5.3 Protein digestion in the small intestine
			27.5.3.1 Overview
			27.5.3.2 Trypsin
			27.5.3.3 Chymotrypsinogen
			27.5.3.4 Aminopeptidases
				27.5.3.4.1 Overview
				27.5.3.4.2 Expression of aminopeptidases
		27.5.4 Amino acid absorption in the small intestine
			27.5.4.1 Overview
			27.5.4.2 Turnover times for small intestine mucosal cells
		27.5.5 Colon and protein digestion
		27.5.6 Ceca and protein digestion
	27.6 Protein synthesis
		27.6.1 Whole-body synthesis and degradation
		27.6.2 Fractional protein synthesis in different organs
		27.6.3 Fractional protein synthesis in muscle
		27.6.4 Ribosomal protein S6 and ribosomal protein S6 kinase (S6K1) and protein synthesis
		27.6.5 Other factors influencing protein synthesis
	27.7 Protein degradation
		27.7.1 Overview
		27.7.2 Autophagy
			27.7.2.1 Overview
			27.7.2.2 Autophagy-related genes
		27.7.3 Ubiquitin and protein degradation
			27.7.3.1 Overview
			27.7.3.2 Atrogin-1/MAFbx and protein degradation in birds
		27.7.4 Lysosomes and protein degradation
			27.7.4.1 Overview
			27.7.4.2 Lysosomal proteases
				27.7.4.2.1 Caspases
				27.7.4.2.2 Cathepsins
		27.7.5 Whole body determination of protein degradation
	27.8 Control of protein synthesis and degradation
		27.8.1 Overview
		27.8.2 Protein kinase B (Akt)/mechanistic (or mammalian) target of rapamycin pathway controlling protein synthesis and degradation
		27.8.3 Protein synthesis and age/development
		27.8.4 Effects of nutritional deficiencies on muscle protein synthesis and degradation
		27.8.5 Effects of stretching on muscle protein synthesis and degradation
		27.8.6 Hormones and muscle protein synthesis
		27.8.7 Microorganisms and protein synthesis in liver and gastrointestinal tract
		27.8.8 Environmental temperature and protein synthesis and degradation
		27.8.9 Protein synthesis and immune functioning
		27.8.10 Other physiological effects on protein synthesis and degradation
			27.8.10.1 Overview
			27.8.10.2 Molt and protein synthesis
	27.9 Proteins and reproduction
		27.9.1 Female reproduction
		27.9.2 Male reproduction
	27.10 Amino acids and metabolism
		27.10.1 Amino acid transfer into muscle and other cells
		27.10.2 Amino acid transporters
			27.10.2.1 Overview
			27.10.2.2 Amino acid transporters and physiological state
	27.11 Nitrogenous waste
		27.11.1 Overview
		27.11.2 Uric acid
		27.11.3 Urea
		27.11.4 Glutamine and ammonia detoxification
		27.11.5 Amino acids as energy sources
			27.11.5.1 Amino acids and metabolism
			27.11.5.2 Glutamine as an energy source
	27.12 Amino acid derivatives
		27.12.1 Overview
		27.12.2 Melanin
	27.13 Extranutritional effects of amino acids
		27.13.1 Overview
		27.13.2 Amino acids in the control of metabolism
			27.13.2.1 Glutamine and muscle growth
			27.13.2.2 Glutamine and intestinal growth
			27.13.2.3 Dipeptides
	27.14 Other uses of avian proteins
	References
	Further reading
28. Food intake regulation
	28.1 Introduction
	28.2 Peripheral regulation of food intake
		28.2.1 Gastrointestinal tract and ghrelin
		28.2.2 Liver
		28.2.3 Dietary nutrients
		28.2.4 Adipose tissue and leptin
	28.3 Central nervous system control of food intake
	28.4 Classical neurotransmitters
	28.5 Peptides
		28.5.1 Neuropeptide Y
		28.5.2 Melanocortins
		28.5.3 Corticotropin-releasing factor, urocortins, and urotensins
		28.5.4 Mesotocin and arginine-vasotocin
		28.5.5 Opioids and kyotorphin
		28.5.6 FMRFamides
		28.5.7 Galanin
		28.5.8 Visfatin
		28.5.9 Somatostatin
		28.5.10 Glucagon superfamily
		28.5.11 Cholecystokinin and gastrin
		28.5.12 Calcitonin family
		28.5.13 Insulin
		28.5.14 Bombesin
		28.5.15 Neuromedin family
	28.6 Selection for single growth-related traits alters food intake control mechanisms
	28.7 Other pathways involved in central appetite regulation
		28.7.1 Cannabinoids
		28.7.2 AMP-activated protein kinase
		28.7.3 Mechanistic target of rapamycin
		28.7.4 Autophagy
	References
	Further reading
29. Overviews of avian neuropeptides and peptides
	29.1 Introduction
		29.1.1 Galanin/spexin peptide family
		29.1.2 Tachykinin peptide family
		29.1.3 Calcitonin peptide family
		29.1.4 Parathyroid hormone family
		29.1.5 Relaxin peptide family
		29.1.6 Ghrelin/motilin peptide family
		29.1.7 NMU/NMS peptide family
		29.1.8 Neuropeptide S
		29.1.9 Neurotensin and neuromedin N
		29.1.10 RF-amide peptide family
		29.1.11 Cholecystokinin and gastrin peptide family
		29.1.12 Orexin peptide family
		29.1.13 Melanin-concentrating hormone peptide
		29.1.14 Prokineticin peptide family
		29.1.15 Corticotropin-releasing hormone peptide family
		29.1.16 Neuropeptide W and neuropeptide B
		29.1.17 Opioid peptide family
		29.1.18 Somatostatin/cortistatin peptide family
		29.1.19 Urotensin II/urotensin II–related peptide family
		29.1.20 Glucagon peptide superfamily
		29.1.21 Apelin and elabela peptides
		29.1.22 Neuropeptide Y family
		29.1.23 Natriuretic peptide family
		29.1.24 Osteocrin peptide
		29.1.25 Neurosecretory protein GL and neurosecretory protein GM family
		29.1.26 Ornitho-kinin peptide
		29.1.27 Angiotensin II peptide
		29.1.28 Endothelin peptide family
		29.1.29 Bombesin peptide family
		29.1.30 Melanocortin system peptides
		29.1.31 Arginine vasotocin/mesotocin peptides
		29.1.32 Cocaine- and amphetamine-regulated transcript peptides
		29.1.33 Leptin
		29.1.34 Thyrotropin-releasing hormone
		29.1.35 Esophageal cancer–related gene 4–derived peptides
		29.1.36 Chemerin
		29.1.37 Granin-derived peptides
		29.1.38 Antimicrobial host defense peptides
		29.1.39 Other peptides
	29.2 Summary
	References
30. Pituitary gland
	30.1 Introduction
	30.2 Embryonic development of the pituitary gland
	30.3 Anatomy of the pituitary gland
		30.3.1 Anatomy of the anterior pituitary gland (pars distalis)
			30.3.1.1 Secretory cells
			30.3.1.2 Folliculo-stellate cells
			30.3.1.3 Macrophage
		30.3.2 Pars intermedia
		30.3.3 Pars tuberalis
		30.3.4 Posterior pituitary gland or pars nervosa
	30.4 Gonadotropins
		30.4.1 Gonadotropin subunits, genes, mRNA, and glycoproteins
			30.4.1.1 Expression of pituitary glycoprotein subunits
		30.4.2 Actions of gonadotropins
			30.4.2.1 Actions of luteinizing hormone in the female
				30.4.2.1.1 Luteinizing hormone and ovulation
				30.4.2.1.2 Luteinizing hormone and steroidogenesis
				30.4.2.1.3 Luteinizing hormone and follicular development
				30.4.2.1.4 Luteinizing hormone and ovarian inhibin/activin receptors
			30.4.2.2 Actions of follicle-stimulating hormone in the female
				30.4.2.2.1 Follicle-stimulating hormone and steroidogenesis
				30.4.2.2.2 Follicle-stimulating hormone and ovarian cell remodeling and proliferation
			30.4.2.3 Actions of luteinizing hormone in the male
			30.4.2.4 Actions of follicle-stimulating hormone in the male
			30.4.2.5 Other actions of follicle-stimulating hormone
			30.4.2.6 Luteinizing hormone receptors
			30.4.2.7 Follicle-stimulating hormone receptors
		30.4.3 Control of gonadotropin release
			30.4.3.1 Introduction
			30.4.3.2 Gonadotropin hormone–releasing hormone
				30.4.3.2.1 Chemistry
					30.4.3.2.1.1 Chicken GnRH 1 (cGnRH1)
					30.4.3.2.1.2 Chicken GnRH 2 (cGnRH2)
				30.4.3.2.2 Biological activity
				30.4.3.2.3 Gonadotropin-releasing hormone receptors and signal transduction
				30.4.3.2.4 Control of gonadotropin-releasing hormone release and synthesis
				30.4.3.2.5 Changes in hypothalamic gonadotropin-releasing hormone content
				30.4.3.2.6 Changes in pituitary responsiveness
				30.4.3.2.7 Extrahypothalamic production of gonadotropin-releasing hormone and gonadotropin-releasing hormone receptors
			30.4.3.3 Gonadotropin-inhibitory hormone
				30.4.3.3.1 Chemistry and synthesis
				30.4.3.3.2 Actions of gonadotropin-inhibitory hormone
				30.4.3.3.3 Gonadotropin-inhibitory hormone receptors
				30.4.3.3.4 Hypothalamic gonadotropin-inhibitory hormone content
				30.4.3.3.5 Extrapituitary expression of gonadotropin-inhibitory hormone
		30.4.4 Control of gonadotropin subunit expression
			30.4.4.1 Control of common α-subunit expression
			30.4.4.2 Control of follicle-stimulating hormone β-subunit expression
			30.4.4.3 Control of luteinizing hormone β subunit expression
		30.4.5 Physiological control of gonadotropins
			30.4.5.1 Episodic secretion of gonadotropins
			30.4.5.2 Feedback and gonadotropin release
			30.4.5.3 Seasonal breeding (photoperiod, temperature, and rainfall)
			30.4.5.4 Preovulatory luteinizing hormone surge
			30.4.5.5 Nutrition and gonadotropin release
		30.4.6 Pituitary origin of gonadotropins
	30.5 Thyrotropin
		30.5.1 Thyrotropin subunits, genes, mRNA, and glycoproteins
		30.5.2 Actions of thyroid-stimulating hormone
			30.5.2.1 Role
			30.5.2.2 Thyroid-stimulating hormone receptors
		30.5.3 Thyroid-stimulating hormone receptor and domestication
		30.5.4 Control of thyroid-stimulating hormone release and subunit expression in the anterior pituitary gland
			30.5.4.1 Thyrotropin-releasing hormone and thyroid-stimulating hormone release and subunit expression
				30.5.4.1.1 Thyrotropin-releasing hormone
			30.5.4.2 Corticotropin-releasing hormone and thyroid-stimulating hormone release and subunit expression
			30.5.4.3 Glucagon-like peptide and thyroid-stimulating hormone release and subunit expression
			30.5.4.4 Somatostatin and thyroid-stimulating hormone release
			30.5.4.5 Negative feedback
			30.5.4.6 Environmental factors and thyroid-stimulating hormone release
		30.5.5 Control of thyroid-stimulating hormone β-subunit expression
		30.5.6 Origin of thyroid-stimulating hormone
			30.5.6.1 Anterior pituitary gland
			30.5.6.2 Extrapituitary thyroid-stimulating hormone
		30.5.7 Ontogeny of thyroid-stimulating hormone
	30.6 Growth hormone
		30.6.1 Growth hormone gene, mRNA, and protein
		30.6.2 Post-translational variants of growth hormone
		30.6.3 Actions of growth hormone
			30.6.3.1 Growth hormone and growth
				30.6.3.1.1 Growth hormone and insulin-like growth factor 1
				30.6.3.1.2 Other mechanisms controlling insulin-like growth factor 1
			30.6.3.2 Growth hormone and lipid metabolism
			30.6.3.3 Growth hormone and carbohydrate metabolism
			30.6.3.4 Growth hormone and thyroid hormones
			30.6.3.5 Growth hormone and immune functioning
			30.6.3.6 Growth hormone and reproduction
			30.6.3.7 Growth hormone and adrenocortical hormones
			30.6.3.8 Growth hormone and apoptosis
			30.6.3.9 Growth hormone receptors and Signal Transduction
			30.6.3.10 Growth hormone binding protein
		30.6.4 Control of growth hormone release
			30.6.4.1 Introduction
			30.6.4.2 Growth hormone–releasing hormone
			30.6.4.3 Ghrelin/growth hormone secretagogue receptor
				30.6.4.3.1 Action and chemistry
				30.6.4.3.2 Growth hormone secretagogue receptor
				30.6.4.3.3 Extrapituitary actions of ghrelin
			30.6.4.4 Neuropeptide W
			30.6.4.5 Thyrotropin-releasing hormone
			30.6.4.6 Glucagon-like peptide
			30.6.4.7 Somatostatin and cortistatin
		30.6.5 Control of growth hormone expression
		30.6.6 Environmental factors and growth hormone release
		30.6.7 Pituitary origin of growth hormone
		30.6.8 Extrapituitary expression of growth hormone
		30.6.9 Ontogeny of growth hormone
			30.6.9.1 Pou 1 (Pit1)
			30.6.9.2 Somatotrophs and their differentiation
			30.6.9.3 Secretion
	30.7 Prolactin
		30.7.1 Prolactin gene, mRNA, and protein
		30.7.2 Post-translational variants of prolactin
		30.7.3 Actions of prolactin
			30.7.3.1 Prolactin and the crop sac gland
			30.7.3.2 Prolactin and behavior
			30.7.3.3 Prolactin and reproduction
			30.7.3.4 Other roles of prolactin and adrenocortical functioning
			30.7.3.5 Prolactin receptor
		30.7.4 Control of prolactin release
			30.7.4.1 Vasoactive intestinal peptide and prolactin release
				30.7.4.1.1 Introduction
			30.7.4.2 Arginine vasotocin
			30.7.4.3 Prolactin-releasing peptide
				30.7.4.3.1 Chemistry
				30.7.4.3.2 Actions
				30.7.4.3.3 Receptors
			30.7.4.4 Neuropeptide W
			30.7.4.5 Dopamine
			30.7.4.6 Other stimulatory factors
		30.7.5 External influences on prolactin release
			30.7.5.1 Photoperiod and prolactin release
			30.7.5.2 Stress and prolactin release
		30.7.6 Prolactin expression
		30.7.7 Adenohypophyseal cells producing prolactin
	30.8 Pro-opiomelanocortin-derived peptides—adrenocorticotropic hormone, lipotropic hormone, melanocyte-stimulating hormone, and  ...
		30.8.1 Pro-opiomelanocortin: gene, processing, and derived peptides
		30.8.2 Actions of adrenocorticotropic hormone
			30.8.2.1 Control of adrenocorticotropic hormone release
				30.8.2.1.1 Corticotropin-releasing hormone
					30.8.2.1.1.1 Other effects of corticotropin-releaseing hormone
				30.8.2.1.2 Arginine vasotocin, mesotocin, and adrenocorticotropic hormone release
				30.8.2.1.3 Calcium-related hormones and adrenocorticotropic hormone release
				30.8.2.1.4 Feedback
		30.8.3 Control of proopiomelanocortin expression
		30.8.4 Pituitary origin of adrenocorticotropic hormone
		30.8.5 Extrapituitary production
		30.8.6 Ontogeny of adrenocorticotropic hormone
		30.8.7 Melanocyte-stimulating hormone and lipotropic hormone
		30.8.8 β-Endorphin
			30.8.8.1 Chemistry of β-endorphin
			30.8.8.2 Physiology of β-endorphin release
			30.8.8.3 Physiological role of β-endorphin
		30.8.9 Extrapituitary production of proopiomelanocortin peptides
	30.9 Other anterior pituitary gland peptides/proteins
		30.9.1 Adiponectin
		30.9.2 Chromogranin A
		30.9.3 Cocaine- and amphetamine-regulated transcript peptides
		30.9.4 Synaptotagmin-1
		30.9.5 Interleukins
	30.10 Pars tuberalis
		30.10.1 Functioning of the pars tuberalis
			30.10.1.1 Pars tuberalis and photoperiodism
		30.10.2 Pineal effects on the pars tuberalis
		30.10.3 Circadian rhythms and the pars tuberalis
	30.11 Neurohypophysis
		30.11.1 Introduction
		30.11.2 Receptors for arginine vasotocin and mesotocin
		30.11.3 Actions of arginine vasotocin
			30.11.3.1 Arginine vasotocin and renal functioning
			30.11.3.2 Arginine vasotocin and oviposition
			30.11.3.3 Cardiovascular effects of arginine vasotocin
			30.11.3.4 Other effects of arginine vasotocin
		30.11.4 Actions of mesotocin
			30.11.4.1 Mesotocin and renal functioning
			30.11.4.2 Mesotocin and oviposition
			30.11.4.3 Other effects of mesotocin
		30.11.5 Neurohypophyseal hormones and behavior
		30.11.6 Control of arginine vasotocin and mesotocin release
			30.11.6.1 Control of arginine vasotocin release
			30.11.6.2 Osmotic-related arginine vasotocin release
			30.11.6.3 Other effects on arginine vasotocin
			30.11.6.4 Arginine vasotocin and mesotocin and oviposition
		30.11.7 Arginine vasotocin and mesotocin expression
		30.11.8 Hormonal influences on the posterior pituitary gland
		30.11.9 Infundibular peptides
	References
	Further reading
31. Thyroid gland
	31.1 Introduction
	31.2 Thyroid gland structure and development
		31.2.1 Structure of the mature thyroid gland
		31.2.2 Thyroid gland development
	31.3 Thyroid hormone synthesis and release
		31.3.1 Thyroid hormone synthesis
			31.3.1.1 Iodide uptake and transport
			31.3.1.2 Iodination and coupling in the colloid
			31.3.1.3 Release into the circulation
		31.3.2 Hypothalamic-Pituitary-Thyroid Axis
			31.3.2.1 Control by the pituitary
			31.3.2.2 Control by the hypothalamus
			31.3.2.3 Development of the hypothalamic-pituitary-thyroid axis
		31.3.3 Thyroid hormones in circulation
			31.3.3.1 Avian thyroid hormone distributor proteins
			31.3.3.2 Factors influencing thyroid hormone levels in circulation
	31.4 Thyroid hormone metabolism and action
		31.4.1 Thyroid hormone activation and degradation
			31.4.1.1 Characterization of avian deiodinases
			31.4.1.2 Role of deiodinases
		31.4.2 Cellular uptake of thyroid hormones
			31.4.2.1 Characterization of avian thyroid hormone transporters
		31.4.3 Mechanism of action of thyroid hormones
			31.4.3.1 Genomic actions via nuclear thyroid hormone receptors
				31.4.3.1.1 Characterization of thyroid hormone receptors in birds
				31.4.3.1.2 Thyroid hormone action mechanism via nuclear Thyroid hormone receptors
			31.4.3.2 Alternative routes of thyroid hormone action
	31.5 Physiological effects of thyroid hormones
		31.5.1 Thyroid hormone effects on development
			31.5.1.1 General development and hatching
				31.5.1.1.1 Precocial versus altricial birds
				31.5.1.1.2 Interaction with other hormones
			31.5.1.2 Development of the brain
			31.5.1.3 Role of maternal thyroid hormones
		31.5.2 Thyroid hormone effects on metabolism and thermoregulation
			31.5.2.1 Effects on intermediate metabolism
			31.5.2.2 Effects on thermogenesis
		31.5.3 Thyroid hormone effects on reproduction
			31.5.3.1 Role in gonadal development and function
				31.5.3.1.1 Impact of hypothyroidism
				31.5.3.1.2 Impact of hyperthyroidism
			31.5.3.2 Role in seasonal reproduction and molt
				31.5.3.2.1 Effects on gonadal growth and regression
				31.5.3.2.2 Effects on molting
	31.6 Environmental influences on thyroid function
		31.6.1 Impact of food availability
		31.6.2 Impact of environmental temperature
		31.6.3 Impact of chemical pollutants
	References
32. Mechanisms and hormonal regulation of shell formation: supply of ionic and organic precursors, shell mineralization
	32.1 Introduction
	32.2 Structure, composition, and formation of the eggshell
		32.2.1 Structure and composition
		32.2.2 Kinetics and site of shell membranes and shell formation
	32.3 Mineral supply: a challenge for calcium metabolism
	32.4 Hormones involved in calcium metabolism of laying hens: vitamin D, parathyroid hormone, calcitonin, and fibroblast growth f ...
		32.4.1 Regulation of vitamin D metabolites in hens
		32.4.2 Role of fibroblast growth factor-23 in regulation in calcium and phosphorus metabolism
		32.4.3 Parathyroid hormone and related peptides
			32.4.3.1 Chemistry, secretion, and function of parathyroid hormone
			32.4.3.2 Regulation by parathyroid hormone of Calcium metabolism
		32.4.4 Calcitonin and calcitonin gene-related peptides
	32.5 Intestinal absorption of calcium
		32.5.1 Mechanisms of intestinal calcium absorption
		32.5.2 Regulation of Calcium absorption in laying hens
	32.6 Medullary bone
		32.6.1 Structure and composition
		32.6.2 Regulation of medullary bone formation and resorption
			32.6.2.1 Induction and maintenance of medullary bone by sex steroid hormones
			32.6.2.2 Role of parathyroid hormone in daily mobilization of medullary bone
	32.7 Uterine secretions of Calcium
		32.7.1 Mechanisms of ionic transfers
			32.7.1.1 Transcellular transfer of Calcium and bicarbonate
			32.7.1.2 Vesicular secretion of calcium
		32.7.2 Regulation of uterine calcium transfer
			32.7.2.1 Regulation of the timing of ion secretion
			32.7.2.2 Regulation of uterine ionic transporters
	32.8 Mineralization of the eggshell
		32.8.1 Mechanisms of shell mineralization and the role of organic matrix
			32.8.1.1 Eggshell temporal and spatial deposition
			32.8.1.2 Role of matrix proteins in the biomineralization process
		32.8.2 Regulation of eggshell matrix protein synthesis
	References
	Further reading
33. Adrenals
	33.1 Anatomy
		33.1.1 Gross anatomy, blood supply, and innervation
		33.1.2 Microanatomy
			33.1.2.1 The chromaffin tissue
			33.1.2.2 The adrenocortical tissue
			33.1.2.3 Extrinsic and intrinsic adrenal innervation
	33.2 Adrenocortical hormones
		33.2.1 Corticosteroid secretory products
		33.2.2 Other secretory products
		33.2.3 Synthesis of corticosteroids
		33.2.4 Transport of corticosteroids
		33.2.5 Circulating concentrations of corticosterone and aldosterone
		33.2.6 Secretion, clearance, and metabolism of corticosterone and aldosterone
		33.2.7 General regulation of adrenocortical function
			33.2.7.1 Adrenocorticotropin
			33.2.7.2 Angiotensins
			33.2.7.3 Other putative regulators
				33.2.7.3.1 Stimulators and positive modulators
					33.2.7.3.1.1 Prolactin and growth hormone
					33.2.7.3.1.2 Calciotropic hormones
					33.2.7.3.1.3 Humoral immune system
				33.2.7.3.2 Inhibitors and negative modulators
					33.2.7.3.2.1 Thyroid hormones
					33.2.7.3.2.2 Androgens
		33.2.8 Regulation of aldosterone secretion
			33.2.8.1 Role of angiotensin II
			33.2.8.2 Mechanism of Ang II action in avian adrenocortical cells
			33.2.8.3 Action of adrenocorticotropin on aldosterone secretion
			33.2.8.4 Action of atrial natriuretic peptide on aldosterone secretion
		33.2.9 Overview of the hypothalamic-pituitary-adrenal axis
		33.2.10 Adrenocortical function in development, maturation, and senescence
	33.3 Physiology of adrenocortical hormones
		33.3.1 Corticosteroid receptors and their action in target cells
		33.3.2 Corticosteroids and intermediary metabolism
			33.3.2.1 Protein metabolism
			33.3.2.2 Lipid metabolism
		33.3.3 Corticosteroids and electrolyte balance
		33.3.4 Corticosteroids and immune function
		33.3.5 Corticosteroids and behavior
	33.4 Adrenal chromaffin tissue hormones
		33.4.1 Catecholamine synthesis and secretion
		33.4.2 Circulating catecholamines and stress response
		33.4.3 Some physiological actions of norepinephrine and epinephrine
		33.4.4 Changes in development, maturation, and senescence
	Acknowledgments
	References
34. Endocrine pancreas
	34.1 Introduction
	34.2 Pancreas embryogenesis and development
		34.2.1 Morphology of avian pancreas (Fig. 34.1)
		34.2.2 Distribution of avian pancreatic endocrine cells between the different pancreatic lobes
		34.2.3 Development of avian pancreas
		34.2.4 Pancreatic hormone levels during development and after hatching
	34.3 Factors controlling pancreatic insulin and glucagon release in birds
		34.3.1 Insulin
		34.3.2 Glucagon
		34.3.3 Somatostatin
		34.3.4 Avian pancreatic polypeptide
	34.4 Insulin and glucagon peptides
		34.4.1 Insulin/preproinsulin, proinsulin, and C-peptides
		34.4.2 Glucagon and glucagon-like peptides
			34.4.2.1 Glucagon structure and physiological effects
			34.4.2.2 GLP-1
			34.4.2.3 GLP-2
	34.5 Glucagon and insulin receptors
		34.5.1 Glucagon receptors
		34.5.2 Insulin receptor
			34.5.2.1 Proximal insulin receptor substrates
			34.5.2.2 PI3K/Akt
			34.5.2.3 P70S6K
			34.5.2.4 mTor
			34.5.2.5 MAPK ERK1/2 pathway
	34.6 General effects of glucagon and insulin
		34.6.1 Insulin and embryonic or posthatch development
		34.6.2 Insulin-glucagon and food intake
		34.6.3 Insulin and the endocrine system
		34.6.4 Insulin and glucose metabolism
		34.6.5 Insulin-glucagon and lipid metabolism
		34.6.6 Insulin and protein metabolism
		34.6.7 Insulin and gene expression
	34.7 Experimental or genetical models
	34.8 Conclusion
	References
35. Reproduction in the female
	35.1 Introduction
	35.2 The ovary
		35.2.1 Embryonic and posthatch development of the ovary
		35.2.2 The juvenile ovary
		35.2.3 The laying hen ovary
			35.2.3.1 Follicle vasculature and blood flow
			35.2.3.2 Follicle innervations
		35.2.4 Follicle development, selection, and establishment of preovulatory hierarchy
		35.2.5 Vitellogenesis
		35.2.6 Oocyte maturation and ovulation
		35.2.7 Postovulatory follicles
		35.2.8 Ovarian steroidogenesis
		35.2.9 Control of ovarian follicle development and functions
			35.2.9.1 Gonadotropin-inhibitory hormone
			35.2.9.2 Gonadotropins (luteinizing hormone and follicle-stimulating hormone)
			35.2.9.3 Ovarian steroids
				35.2.9.3.1 Progesterone
				35.2.9.3.2 Androgens
				35.2.9.3.3 Estrogens
			35.2.9.4 Growth hormone
			35.2.9.5 Prolactin and prolactin-like protein
			35.2.9.6 Ghrelin
			35.2.9.7 Thyroid hormones
			35.2.9.8 Adipokines
		35.2.10 Ovarian tissue remodeling
		35.2.11 Follicle atresia
		35.2.12 Chicken ovary as a model for human ovarian cancerogenesis
	35.3 The oviduct
		35.3.1 Infundibulum
		35.3.2 Magnum
		35.3.3 Isthmus
		35.3.4 Shell gland
			35.3.4.1 Eggshell calcification
			35.3.4.2 Eggshell cuticle and pigment deposition
		35.3.5 Vagina
		35.3.6 Sperm storage in birds
		35.3.7 Hormonal and physiological regulation of oviduct development and function
			35.3.7.1 Ovarian steroids
			35.3.7.2 Other factors
	35.4 The ovulatory cycle
	35.5 Egg transportation and oviposition
	35.6 The egg
		35.6.1 The yolk
		35.6.2 The albumen
		35.6.3 The eggshell
			35.6.3.1 The shell membranes
			35.6.3.2 The mammillary layer
			35.6.3.3 The crystal layer
			35.6.3.4 The cuticle
			35.6.3.5 The respiration through the eggshell
	References
	Further reading
36. Reproduction in male birds
	36.1 Introduction
	36.2 Reproductive tract anatomy
		36.2.1 Testis
		36.2.2 Excurrent ducts
		36.2.3 Accessory organs
	36.3 Ontogeny of the reproductive tract
		36.3.1 Overview
		36.3.2 Formation of the undifferentiated Gonad
		36.3.3 Gonadal differentiation and Müllerian duct regression
		36.3.4 Formation of the excurrent ducts
	36.4 Development and growth of the testis
		36.4.1 Proliferation of somatic and stem cells in the testis
		36.4.2 Differentiation of somatic cells within the testis
		36.4.3 Initiation of meiosis
		36.4.4 Altering the pattern of testis growth and maturation
	36.5 Hormonal control of testicular function
		36.5.1 Central control of testicular function
		36.5.2 Control of adenohypophyseal function in males
		36.5.3 Effects of gonadotropins on testicular function
	36.6 Spermatogenesis and extragonadal sperm maturation
		36.6.1 Spermatogenesis
		36.6.2 Extragonadal sperm transport and maturation
	36.7 Seasonal gonadal recrudescence and regression
		36.7.1 Photoperiodic control of gonadal regression and recrudescence
		36.7.2 Other factors affecting gonadal maturation and regression
	References
37. The physiology of the avian embryo
	37.1 Introduction
	37.2 The freshly laid egg
	37.3 Incubation
		37.3.1 Incubation period
		37.3.2 Egg water content and shell conductance
		37.3.3 Heat transfer
		37.3.4 Energy use
	37.4 Development of physiological systems
		37.4.1 Gas exchange
		37.4.2 Acid-base regulation
		37.4.3 Cardiovascular system
			37.4.3.1 Basic cardiovascular parameters
			37.4.3.2 Mean heart rate
			37.4.3.3 Instantaneous heart rate
			37.4.3.4 Cardiovascular regulation
		37.4.4 Osmoregulation
		37.4.5 Thermoregulation
	37.5 Artificial incubation
		37.5.1 Preincubation egg storage
		37.5.2 Egg turning
		37.5.3 Ambient temperature and incubation
		37.5.4 Humidity
	37.6 Conclusions and future directions
	Acknowledgments
	References
38. Stress ecophysiology
	38.1 Introduction
	38.2 Stress, energy, and glucocorticoids
		38.2.1 Allostasis: the concept and the model
		38.2.2 Glucocorticoid levels
		38.2.3 “Wear and tear” and the reactive scope model
	38.3 Adrenocortical response to environmental change
		38.3.1 Predictable versus unpredictable environmental change
		38.3.2 Indirect, labile (short-term) perturbations
		38.3.3 Direct, labile (short-term) perturbations and the “emergency life history stage”
		38.3.4 Permanent (long-term) perturbations or “modifying factors”
	38.4 Phenotypic plasticity and selection on the stress response
		38.4.1 The stress response during development
		38.4.2 Maternal effects
		38.4.3 Modulation of the stress response
	38.5 Field methods to study adrenocortical function
		38.5.1 Obtaining adequate blood samples: capture and restraint protocols and the “stress series”
		38.5.2 Quantifying the strength and sensitivity of adrenocortical responses
		38.5.3 Phenotypic engineering
		38.5.4 Corticosterone and its metabolites in tissues other than blood
			38.5.4.1 Feathers
		38.5.5 Corticosterone metabolites in droppings (excreta)
	Glossary of terms
	Acknowledgments
	References
39. Avian welfare: fundamental concepts and scientific assessment
	39.1 Introduction
	39.2 What is animal welfare?
	39.3 Birds are sentient and their welfare should be considered
		39.3.1 Birds are sentient and different states of consciousness can be recognized
	39.4 How can bird welfare be scientifically assessed?
		39.4.1 The Five Domains model for welfare assessment
		39.4.2 Hierarchy of evidence to support specific affective experiences in birds
	39.5 Avian welfare research to date
		39.5.1 Key welfare issues in commercial poultry production
	39.6 Case study—evaluation of the potential for chickens to experience negative states due to carbon dioxide stunning
	39.7 General conclusions
	References
40. Reproductive behavior
	40.1 Introduction
	40.2 Regulation of reproductive behavior
	40.3 Environmental factors
		40.3.1 Temperature and climate change
		40.3.2 Light
		40.3.3 Food resources
		40.3.4 Case study: urbanization
	40.4 Social factors
		40.4.1 Effects of males on conspecific females
		40.4.2 Effects of females on conspecific males
		40.4.3 Effects of males on conspecific males
		40.4.4 Effects of females on conspecific females
	40.5 Age and experience
	40.6 Endocrine and neuroendocrine regulation of reproductive behavior
		40.6.1 Gonadal steroids
		40.6.2 Neurosteroids
		40.6.3 Gonadotropin-releasing and gonadotropin-inhibitory hormones
		40.6.4 Arginine vasotocin
		40.6.5 Prolactin
		40.6.6 Case study: the oscine vocal control system
	References
41. Growth
	41.1 Introduction
		41.1.1 Overview
		41.1.2 Growth curves
			41.1.2.1 Logistic equation
			41.1.2.2 Gompertz model
		41.1.3 Growth of different organs
	41.2 Evolutionary perspectives of avian growth
	41.3 Altricial versus precocial birds
	41.4 Sexual dimorphism in growth
		41.4.1 Overview
		41.4.2 Sexual dimorphism in domesticated birds
		41.4.3 Sexual dimorphism in wild birds
	41.5 Growth hormone
		41.5.1 Overview
		41.5.2 Chemistry and evolution of GH
		41.5.3 GH and growth
		41.5.4 GH receptors
		41.5.5 Sex-linked dwarf chickens as a model for growth hormone action
	41.6 Insulin-like growth factors
		41.6.1 Overview
		41.6.2 Chemistry and evolution of IGF1 and IGF2
		41.6.3 IGFs and growth
		41.6.4 IGF1 and muscle and adipose growth
		41.6.5 IGF receptors
		41.6.6 Nutrition and IGF1
		41.6.7 IGF1 and IGF2 in wild birds
		41.6.8 Insulin-like growth factor–binding proteins
			41.6.8.1 Overview
			41.6.8.2 Nutrition and IGFBPs
		41.6.9 Insulin-like growth factor 2–binding proteins
	41.7 Thyroid hormones (hypothalamo–pituitary–thyroid axis)
		41.7.1 Overview
		41.7.2 Thyroid hormones and growth
		41.7.3 Thyroid hormones and wild birds
	41.8 Sex steroid hormones
		41.8.1 Overview
		41.8.2 Sex steroids and poultry
		41.8.3 Sex steroids and wild birds
	41.9 Adrenocorticotropin and glucocorticoids (hypothalamo–pituitary–adrenocortical axis)
		41.9.1 Overview
		41.9.2 Are glucocorticoids required for development and growth?
		41.9.3 Glucocorticoid depression of growth
	41.10 Insulin
	41.11 Growth factors
		41.11.1 Overview
	41.12 Epidermal growth factor and transforming growth factor-α
		41.12.1 Chemistry of EGF and TGF-α
		41.12.2 EGFR receptor
		41.12.3 Actions of EGF and TGF-α
	41.13 Transforming growth factor-β
		41.13.1 Structure of avian TGF-βs
		41.13.2 Physiology of avian TGF-βs
		41.13.3 Myostatin
			41.13.3.1 Myostatin poultry
			41.13.3.2 Myostatin in wild birds
	41.14 Bone morphogenetic protein
		41.14.1 Overview
		41.14.2 Bone morphogenetic protein 1 and tolloid
		41.14.3 Bone morphogenetic protein 2
		41.14.4 Bone morphogenetic protein 3
		41.14.5 Bone morphogenetic protein 4
	41.15 Fibroblast growth factors
		41.15.1 Overview
		41.15.2 Endocrine FGFs, FGF receptors, and signal transduction
		41.15.3 Fibroblast growth factors 19
		41.15.4 FGF23
			41.15.4.1 Overview
			41.15.4.2 FGF23 actions
		41.15.5 Other FGFs
		41.15.6 FGF receptors
	41.16 Neurotrophins
	41.17 Cytokines
		41.17.1 Cytokines
		41.17.2 Tumor necrosis factor-α (TNF-α)
	41.18 Genetics and growth
	41.19 Nutrition and growth
	41.20 Environment and growth
		41.20.1 Light and growth
	References
	Further reading
42. Circadian rhythms
	42.1 Environmental cycles
		42.1.1 Light cycles
		42.1.2 Temperature
		42.1.3 Other physical cycles
		42.1.4 Rhythms in the biotic environment
	42.2 Circadian rhythms
		42.2.1 Formal properties
		42.2.2 Stability and lability of circadian rhythms
		42.2.3 Entrainment
		42.2.4 Masking
	42.3 Photoreceptors
		42.3.1 Encephalic photoreceptors
		42.3.2 Pineal gland
		42.3.3 Retina
	42.4 Pacemakers
		42.4.1 Pineal gland and melatonin
		42.4.2 Retinae
		42.4.3 Suprachiasmatic nuclei
	42.5 Sites of melatonin action
		42.5.1 Melatonin receptors
		42.5.2 Mechanisms of action
	42.6 Avian circadian organization
	42.7 Molecular biology
		42.7.1 Identification, characterization, and localization of molecular clockworks in birds
		42.7.2 Peripheral oscillators in avian circadian clocks
		42.7.3 Prospects for transgenesis and molecular manipulation of avian clocks
	42.8 Conclusion and perspective
	References
	Further reading
43. Circannual cycles and photoperiodism
	43.1 Annual cycles
		43.1.1 Abiotic
			43.1.1.1 Photoperiod
			43.1.1.2 Temperature
			43.1.1.3 Precipitation and wind
		43.1.2 Biotic
	43.2 Annual cycles of birds
	43.3 Circannual rhythms
		43.3.1 Circannual rhythms in the lab
		43.3.2 Synchronization of circannual rhythms to environmental cues
	43.4 Photoperiodism
		43.4.1 Effects of photoperiod on avian physiological function
		43.4.2 Role of photoreceptors
		43.4.3 Role of circadian clocks in photoperiodic time measurement
		43.4.4 Role of circadian system structures
	43.5 Neuroendocrine regulation of photoperiodic time measurement
		43.5.1 Photoperiodic control of gonadotropins and prolactin in seasonal reproduction
		43.5.2 Role of the thyroid hormone in avian photoperiodism
		43.5.3 Role of gonadal and neural steroids
		43.5.4 Mechanisms of photoperiodic regulation of bird song
		43.5.5 Mechanisms of photoperiodic regulation of migration
	43.6 Molecular mechanisms of photoperiodism
	43.7 Comparison to other vertebrate taxa
	43.8 Conclusion
	References
44. Annual schedules
	44.1 Introduction
	44.2 Background: patterns of environmental variation and avian annual schedules
	44.3 Effects of environmental cues on annual scheduling and underlying mechanisms
		44.3.1 Photoperiodic response
		44.3.2 Processing of nonphotic cues
			44.3.2.1 Effects of temperature
			44.3.2.2 Effects of food
			44.3.2.3 Effects of behavioral factors
		44.3.3 Integration of multiple cue types: parallel or serial processing?
	44.4 Adaptive variation in cue processing mechanisms as it relates to life in different environments
	44.5 Integrated coordination of stages and carryover effects
	44.6 Variation in scheduling mechanisms and responses to rapid environmental change
	44.7 Effects of seasonality on constitutive processes
		44.7.1 Seasonal modulation of immune function
		44.7.2 Seasonal modulation of responses to stressors
		44.7.3 Seasonal modulation of metabolic machinery
	References
45. Regulation of body temperature: patterns and processes
	45.1 Introduction
	45.2 The evolution of avian endothermy
	45.3 Models of avian thermoregulation
		45.3.1 Overall heat balance
		45.3.2 Avian endothermic homeothermy
		45.3.3 Deviations from the Scholander–Irving model
		45.3.4 Thermal conductance
	45.4 Body temperature
		45.4.1 Measurement of body temperature
		45.4.2 Normothermic body temperature
		45.4.3 Hyperthermic body temperature
			45.4.3.1 Fever
		45.4.4 Hypothermic body temperature
	45.5 Avenues of heat transfer and behavioral modifications
		45.5.1 Radiation
		45.5.2 Convection
		45.5.3 Conduction
		45.5.4 Evaporation
			45.5.4.1 Respiratory evaporative water loss
				45.5.4.1.1 Panting
				45.5.4.1.2 Gular flutter
			45.5.4.2 Cutaneous evaporative water loss
			45.5.4.3 Other avenues of evaporative cooling
		45.5.5 Heat dissipation challenges in commercial poultry production
	45.6 Metabolic heat production
		45.6.1 Basal metabolic rate
		45.6.2 Resting metabolic thermogenesis and cold tolerance
		45.6.3 Metabolic costs of evaporative cooling
	45.7 Physiological control of thermoregulation
		45.7.1 Thermoception
		45.7.2 Neuronal integration
		45.7.3 Efferent outputs
		45.7.4 Circulatory adjustments of heat transfer
	45.8 Development of thermoregulation
		45.8.1 The altricial–precocial spectrum
		45.8.2 Developmental plasticity of thermoregulation
	45.9 Avian thermoregulation and global heating
	References
46. Flight
	46.1 Introduction
	46.2 Scaling effects of body size
	46.3 Energetics of bird flight
		46.3.1 Techniques used to study the mechanical power output required for flight
			46.3.1.1 Aerodynamic and biomechanical models
			46.3.1.2 Air flow visualization and direct force measurements
		46.3.2 Techniques used to measure the power input required for flight
			46.3.2.1 Mass loss
			46.3.2.2 Doubly labeled water
			46.3.2.3 13C sodium bicarbonate
			46.3.2.4 Telemetry and data logging
				46.3.2.4.1 Heart rate
				46.3.2.4.2 Accelerometry
			46.3.2.5 Respirometry
			46.3.2.6 Modeling of cardiovascular function
		46.3.3 Empirical data concerning the power input during flight
			46.3.3.1 Gliding and soaring flight
			46.3.3.2 Forward flapping flight
			46.3.3.3 To flap or not to flap: that is the question
			46.3.3.4 Hovering flight and hummingbirds
			46.3.3.5 Scaling of flight muscle efficiency and elastic energy storage
	46.4 The flight muscles of birds
		46.4.1 Flight muscle morphology and fiber types
		46.4.2 Biochemistry of the flight muscles
		46.4.3 Neurophysiology and muscle function
	46.5 Development of locomotor muscles and preparation for flight
	46.6 Metabolic substrates for endurance flight
	46.7 The cardiovascular system
		46.7.1 The cardiac muscles
		46.7.2 Cardiovascular adjustments during flight
	46.8 The respiratory system
		46.8.1 Ventilatory adjustments during flight and ventilatory/locomotor coupling
		46.8.2 Respiratory water loss
		46.8.3 Temperature control
	46.9 Migration and long-distance flight performance
		46.9.1 Preparation for migration
		46.9.2 Migratory behavior
	46.10 Flight at high altitude
		46.10.1 Physiology and adaptation
	Acknowledgments
	References
47. Physiological challenges of migration
	47.1 Introduction
	47.2 Adaptations of birds for long-duration migratory flights
		47.2.1 Cardiovascular and respiratory general adaptations
		47.2.2 Metabolism and damage control
		47.2.3 Immunity
		47.2.4 Sensory systems and navigation
		47.2.5 Endocrine system and the environment
	47.3 Endocrinology of migration
		47.3.1 Vernal stage
			47.3.1.1 Synchronization with the environment: initial predictive cue
			47.3.1.2 Developmental phase: hyperphagia and fattening
			47.3.1.3 Thyroid hormones
			47.3.1.4 Testosterone
			47.3.1.5 Insulin and glucagon
			47.3.1.6 Glucocorticoids (Box 47.1)
			47.3.1.7 Leptin
			47.3.1.8 Ghrelin
			47.3.1.9 Prolactin
			47.3.1.10 Hormones of flight muscle hypertrophy
			47.3.1.11 Mature expression—hormones of the fueling and flight cycle
			47.3.1.12 Termination: arrival biology
		47.3.2 Autumnal stage
			47.3.2.1 Development phase
			47.3.2.2 Thyroid hormones
			47.3.2.3 Androgen
			47.3.2.4 Glucagon
			47.3.2.5 Mature expression—hormones of the fueling and flight cycle
			47.3.2.6 Stopover: arrival
			47.3.2.7 Stopover: departure
			47.3.2.8 Termination—arrival
		47.3.3 Conclusions to endocrine system
	47.4 Physiological aspects of migratory preparation and long-duration flight: fueling/flight cycle
		47.4.1 Introduction
		47.4.2 Feeding
			47.4.2.1 Hyperphagia
			47.4.2.2 Balancing the energy costs of hyperphagia
			47.4.2.3 Fasting and refeeding during migration
			47.4.2.4 Diet selection during migration
		47.4.3 Fuel storage
			47.4.3.1 Fats are the primary fuel
			47.4.3.2 Physiological challenges associated with fatty acids as fuels
			47.4.3.3 Fat quality is dynamic, affected mostly by diet, and changes seasonally during migration
			47.4.3.4 Physiology of protein storage and flight muscle preparation
		47.4.4 Fuel use
			47.4.4.1 Patterns of change in fatty acid composition of birds during migratory stage: proposed hypotheses
			47.4.4.2 The oxidative costs of burning fat as fuel
			47.4.4.3 Carry over effects from winter to breeding
			47.4.4.4 Fat quality matters
			47.4.4.5 Testing the fuel, membrane, and signal hypotheses
			47.4.4.6 Fatty acid transport really matters
			47.4.4.7 Protein use during flight and water balance
			47.4.4.8 Rebuilding protein stores after flight
		47.4.5 Temperature regulation during flight
		47.4.6 Flight at high altitude
	47.5 Beyond systems
	References
48. Actions of toxicants and endocrine disrupting chemicals in birds
	48.1 Introduction
	48.2 Environmental chemicals: utilities and hazards?
		48.2.1 Chemical sources and production
		48.2.2 Assessing the safety of chemicals
			48.2.2.1 Assessing multigenerational impacts in the Japanese quail model
			48.2.2.2 Effects of environmental chemical impacts in wild birds
	48.3 Life cycle of chemicals: endocrine disrupting chemicals in the environment
		48.3.1 Parent compounds and their metabolites in the environment
		48.3.2 Environmental contamination by industrial chemicals and mixtures
	48.4 Classes of endocrine disrupting chemicals and their physiological actions
		48.4.1 Categorizing endocrine disruptors according to structure and function
		48.4.2 Mechanisms of action of endocrine disrupting chemicals in vertebrates
		48.4.3 Interactions of endocrine disrupting chemicals and specific receptors
		48.4.4 Discerning endocrine disrupting chemical impacts in field birds
		48.4.5 Establishing reliable and sensitive measures of adverse impacts
	48.5 Methods for assessing risk
		48.5.1 Predicting impact: toxic equivalency factor and toxic equivalent quotient
	48.6 Frameworks for visualizing risk and effects from endocrine disrupting chemical exposure
		48.6.1 Visualizing predicting risk through influence diagrams and adverse outcomes pathways
			48.6.1.1 Influence diagrams
			48.6.1.2 Adverse outcomes pathways
		48.6.2 The one health concept
	48.7 Why are birds unique?
		48.7.1 Altricial versus precocial birds: ontogeny and vulnerable life stages
		48.7.2 Maternal deposition of compounds
		48.7.3 Posthatch growth and maturation
	48.8 Investigating endocrine disrupting chemical effects in an avian model: the Japanese quail two-generation test
		48.8.1 Pertinent endpoints for assessing potential endocrine disruption
		48.8.2 Survival
		48.8.3 Food consumption and body weight
		48.8.4 Accessory sex characteristics; sexual maturation
		48.8.5 Behavioral indicators
		48.8.6 Egg production, shell quality, fertility, and embryo viability
		48.8.7 Neuroendocrine systems regulating reproduction, metabolism, and stress
		48.8.8 Songbirds
		48.8.9 Metabolic and thyroid systems
		48.8.10 Histopathology
	48.9 Conclusions
	Acknowledgments
	References
49. Blood supplement
	References
	Further reading
50. Carbohydrate supplementary materials
	References
	Further reading
Index
	A
	B
	C
	D
	E
	F
	G
	H
	I
	J
	K
	L
	M
	N
	O
	P
	Q
	R
	S
	T
	U
	V
	W
	X
	Y
	Z