Osmoregulation in Birds: (12 Zoophysiology)

The approach of this treatise is physiological throughout. In the eyes of the author it answers the rhetorical question raised by Maurice B. Visscher at the Physiology Congress in Washington D. C. in 1968: Does physiology exist? What he meant by this question was whether the fields of cellular physiology and physiology of the various organ systems had become so large that physiology as such had vanished. The firm answer is that physiology does indeed exist. Although it is important to study physiological problems at the subcellular level, it is importan- and equally difficult - to study organ regulation at the cellular level, organ interaction, and integration into the whole organism. An account of avian osmoregulation from an integrated point of view is attempted in this book. Since reading Homer W. Smith's From Fish to Philosopher and August Krogh's Osmoregulation in Aquatic Animals verte­ brate osmoregulation has been in the center of the author's interest. The focus was set on avian osmoregulation after personal contact with the School of Krogh when working in the laboratory of Bodil M. Schmidt-Nielsen. The fundamental concepts and isotope techniques introduced by Hans H. Ussing have been of constant inspiration. An excellent example for the study of osmoregulation at the cellular level was given by the late Jean Maetz. The writing of this book was suggested by Donald S. Farner who is thanked for thorough editorial assistance, and especially with help in the subtle semantic peculiarities of the English language.

Table of Contents:
1 Introduction.- 1.1 Problems of Osmoregulation.- 1.2 Review of Reviews.- 1.3 Anatomy of Body Fluids.- 2 Intake of Water and Sodium Chloride.- 2.1 Thirst and Appetite for Salt.- 2.2 Problems of Interpretation of Preference and Discrimination Tests.- 2.3 Drinking of Fresh Water.- 2.4 Salinity Tolerance.- 2.5 Salt Requirements of Domestic Birds.- 3 Uptake Through the Gut.- 3.1 Absorption of Salt and Water in the Small Intestine.- 3.2 Osmotic and Solute Composition of Contents of the Small Intestine.- 3.3 Caecum: Role in Osmoregulation.- 4 Evaporation.- 4.1 Evaporation from Resting Birds Under Thermoneutrality.- 4.2 Reaction to Heat Loads.- 4.3 Reaction to Dehydration.- 5 Function of the Kidney.- 5.1 Excretion of Water and Salts.- 5.2 Action of Antidiuretic Hormones.- 5.3 Renal Nitrogen Excretion.- 6 Function of the Cloaca.- 6.1 General Aspects of Cloacal Function.- 6.2 Studies of Cloacal Absorption of Ureteral Urine.- 6.3 In-vivo Instillation and Perfusion Studies.- 6.4 In-vitro Studies of Transport Parameters of Coprodeum and Colon of the Domestic Fowl.- 6.5 Effects of Aldosterone on Cloacal Transport.- 7 Function of the Salt Gland.- 7.1 Development of the Gland.- 7.2 Stimulus for Secretion.- 7.3 The Flow Rate and Ionic Composition of the Salt-Gland Fluid.- 7.4 Mechanism of Secretion.- 7.5 Adaptation and Hormones.- 7.6 Quantitative Role of Salt Gland in Excretion of an Acute Salt Load and Relation to Kidney/Cloaca in Salt/Water Balance.- 8 Interaction Among the Excretory Organs.- 8.1 Birds Without Salt Glands.- 8.2 Birds with Salt Glands.- 9 A Brief Survey of Hormones and Osmoregulation.- 9.1 Corticosterone and Aldosterone.- 9.2 Hypothalamo-Hypophyseal Hormones.- 9.3 The Pituitary-Adrenal Axis; Renal and Extrarenal Secretions.- 9.4 A Note on the Renin-Angiotensin Systemof Birds.- 10 Problems of Life in the Desert, of Migration, and of Egg-Laying.- 10.1 Desert Birds.- 10.2 Problems of Osmoregulation During Migratory Flights.- 10.3 Osmotic Problems of Nestling Birds.- 10.4 Water and Salt Metabolism in Relation to Egg-Laying.- References.- Systematic and Species Index.