Temperature Regulation In Mammals And Other Vertebrates

A comprehensive analysis of the evolutionary progression and the physiology of temperature regulation in vertebrates.

How do mammals manage to maintain their body temperature within the same narrow range in environments as different as polar regions and hot deserts? This advanced text describes the morphological features and physiological mechanisms by which humans and other mammals maintain their body temperature within a narrow range despite large variations in climatic conditions and internal heat production. Its 19 chapters deal with the physics of heat exchange with the environment, and the autonomic and behavioural mechanisms available to control the loss and production of heat. The neuronal basis of temperature regulation and current concepts of the central nervous interface between temperature signals generated in the body and control mechanisms are examined in detail. This book is of invaluable help for undergraduates, postgraduates, teachers, physicians and scientists.

Cover thermoregulation of invertebrates, fish, amphibia, reptiles and birds, each written by an expert in the field.

Temperature is one facet in the mosaic of physical and biotic factors that describes the niche of an animal. Ofthe physical factors it is ecologically the most important. for it is a factor that is all-pervasive and one that. in most environments. lacks spatial or temporal constancy. Evolution has produced a wide variety of adaptive strategies and tactics to exploit or deal with this variable environmental factor. The ease with which temperature can be measured. and controlled experimentally. together with its widespread influence on the affairs of animals. has understandably led to a large. dispersed literature. In spite of this no recent book provides a comprehensive treatment of the biology of animals in relation to temperature. Our intention in writing this book was to fill that gap. We hope we have provided a modern statement with a critical synthesis of this diverse field. which will be suitable and stimulating for both advanced undergraduate and post graduate students of biology. This book is emphatically not intended as a monographical review. as thermal biology is such a diverse. developed discipline that it could not be encompassed within the confines of a book of this size.

This 1980 second edition of a 1965 original offers a thorough appraisal of the field of mammal physiology.

Chapter 1 "Temperature Regulation in Animals" There are, broadly speaking, two kinds of animals with regard to body temperature: exothermic (cold-blooded) and endothermic (warm-blooded) animals. The exothermic animals, such as reptiles, do not supply body heat by metabolic conversion of food to heat. Reptiles allow their surroundings to determine their body temperature. They lie out in the sun to warm their body. If they are too hot, they seek the shade or even burrow into the ground. At night they hide from the cold in burrows or squeeze into cracks between rocks or hide in leaf cover. Reptiles avoid the extremes of temperature. When reptiles become cool, their movements slow down, and chemical processes in their bodies, such as digestion, are inhibited. Predators, such as hawks and eagles, find it easier to prey on lizards and snakes in cooler weather. The distribution of reptiles is somewhat limited by their exothermic character. They do not thrive in cold climates1. What are the advantages and disadvantages in being exothermic? When the lizard is in a cool environment and cannot find a warmer spot, its body simply cools to the temperature of the surroundings. It is not necessary for the exothermic lizard to generate heat to increase its body temperature. This means that the lizard uses less energy and does not have to eat as much. As the lizard cools its digestion, breathing rate and heart rate slow, saving energy. A disadvantage occurs when the cool lizard is attacked by a predator. If warm, he could run fast and have a much better chance of 1 St. Patrick did not chase the snakes out of Ireland. Ireland was already completely free of snakes. St. Patrick was instrumental in converting pagans to Christianity. Since the snake was a symbol used in pagan rituals, St. Patrick was influential in ridding Ireland of the ritual use of symbolic snakes. 10 Verne A. Simon evading capture. A warm lizard being chased by a predator can move quite fast for a short distance, but like other exotherms, lacks endurance and soon tires. When the exotherm is running fast, its effort is anaerobic, that is, is not using oxygen, and lactic acid is building up in its body. It soon tires and is unable to exert itself. It must recover by taking in oxygen to rid the body of lactic acid. Another disadvantage of exothermic life is that cold climates are not available as habitat. If there is a sudden climate change, an exothermic animal wouldn't be able to mount the sustained effort needed to migrate to a better environment. The exothermic creature might simply perish. About 180 million years ago, mammals appeared. Mammals are endothermic (warm-blooded) and are able to maintain a nearly constant body temperature regardless of the temperature of their surroundings within wide limits. Their bodies will not tolerate too high or too low a temperature. If the surroundings are too hot or cold, causing the body temperature to exceed allowed limits, the animal will die. Mammals have furry coats to help them tolerate low temperatures. Sea-dwelling mammals whales, seals, and walrus have thick layers of blubber for insulation. Birds are endothermic and have feathers to protect them from the cold. Many types of birds and mammals survive in cold climates. Emperor penguins even live in the Antarctic, in the coldest climate on earth. Under normal circumstances, mammals and birds manage to keep this very nearly constant body temperature regardless of the temperature of their surroundings. Mammals are characterized by having body hair and suckling their young. This latter behavior gives the class its name; mammals must have mammary glands. A second advantage is that endothermic animals are not limited to activity only in daylight hours. In many locations, it is too cold at night for exotherms to be active. Even very cold temperatures do not exclude endothermic animals such as mammals and birds from nocturnal activity. Exothermic animals are not normally found in cold c

This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact.