Morphogeny of the nasal skull was investigated in 92 embryos of 13 species of Cetacea. Compared to the original nasal capsule of land mammals, the nasal structures of Cetacea show many weighty transformations. As a result, the nostrils are translocated from the tip of the snout to the vertex of the head. Several structures of the embryonic nasal skull remain preserved even in adult cetaceans. The translocation of the nostrils to the highest point of the surfacing body is among the most perfect adaptations of cetaceans to the aquatic life habits. The morphogeny of the nasal skull suggests that all cetaceans are of common origin and form a single monophyletic order. The hitherto usual division of this order into two suborders, Mysticeti and Odontoceti, appears to be unsubstantiated. Rather, at least three closely related superfamilies should be distinguished within the order Cetacea, viz., Balaenopteroidea, Physeteroidea, and Delphinoidea. The results are in a

In this treatise, current knowledge on the neurogenesis, axonal outgrowth, synaptogenesis, and regenerative capacity of descending supraspinal pathways in tetrapods is discussed. Although emphasis is on the clawed toad, Xenopus laevis, chicken embryos, opossums and rodent data, also the data available for primates including man are presented. It will be shown that 1) the outgrowth of descending supraspinal pathways is the result of a coordinated program; 2) the pattern of early descending axonal tracts is similar in all vertebrate groups; 3) the formation of descending supraspinal pathways occurs according to a developmental sequence; 4) the earliest descending supraspinal fibers arrive in a rather immature spinal cord, and 5) the regenerative capacity of descending supraspinal pathways depends on the developmental stage the particular pathways arise.

Originally published in 1991, this book reviews the various metabolic and functional mechanisms that animals possess in order to live successfully in their own particular, often unique, environments. The book's purpose is to demonstrate both the diversity of responses that are shown (be they biochemical, physiological or behavioural) and to demonstrate the underlying principles of gas exchange and transport for a wide range of diverse organisms. What results is a useful review and analysis of our modern understanding of the respiratory physiology of helminths, crustacea, amphibians, reptiles, birds and mammals. The approach taken by the editors is essentially comparative and the individual authors were chosen so as to provide a useful, complementary view of the subject.

This book gives a concise account of the physiology and form of the fish circulatory system. The emphasis is primarily on function, but details of structure have been included. Following a revision of ideas on hemodynamics, attention is focused on the heart as the primary pump in the fish circulatory system. The fine structure and the electrical and ionic events of cardiac myocytes are described and the major events of the cardiac cycle are outlined. The structure of the peripheral vessels then follow and attention is devoted to the circulation in certain special areas such as the gills, the renal portal system, and the secondary blood system. There are also chapters devoted to the blood and the hemopoetic tissues and an account is given of the different types of retial systems that concentrate oxygen or heat in various parts of the body. Following a description of the autonomic nervous system, the circulatory responses to exercise and hypoxia are described. The book concludes with a discussion on the circulation of hagfish and how it illuminates our understanding of the functional and structural evolution of the circulatory system.

Only five years ago, nobody in his right mind would have consid ered publishing a book on reeler as a model for brain develop ment. Although this interesting mutation has been with us for half a century, it is fair to say that, in spite of a wave of enthusiasm in the late sixties and early seventies, generated primarily by Sidman, Caviness and colleagues, studies of reeler mice fell pro gressively out of fashion during the next two decades. All that changed almost overnight when the cloning of the reeler gene, dubbed reelin, was reported in Tom Curran's laboratory in 1995. The fact that the same gene was identified at the same time independently by two other groups using positional cloning sug gested strongly that reelin was the right candidate. Although the key experiments of transgenic rescue have not been made (and perhaps will never be), the equation "reeler is reelin" has been established beyond reasonable doubt, as alterations of the reelin gene and/or its expression have been found in at least five alleles of reeler and in the mutation Shaking Rat Kawasaki (SRK), an ortholog of reeler."

Due to their pronounced intraspecific variability and to difficulties in defining their evolutionary trends in mammalian phylogenies, peripheral blood vessels have been neglected in comparative studies. Supported by the Sonderforschungsbereich 89 (Car- diology) of the Deutsche Forschungsgemeinschaft, we have reconstructed the ontoge- of the blood vessels of the tree shrew, Tupaia belangeri, on the netic morphogenesis basis of a series of developmental stages. The arteries of the lower extremity are described and discussed here. Besides describing the morphogenesis of the arteries in Tupaia, it is the aim of this study to explain the variability of the arteries of the pelvic extremity among mammals, and especially among primates including man, on the basis of a common developmen- tal pattern. This can be shown in the following example. In the popliteal region of most adult mammals the arteria poplitea profunda is situated under the musculus popliteus. In the adult Tupaia, as well as in primates, this artery is missing but, superficial to the musculus popliteus, an arteria poplitea super- ficialis exists. It seems difficult to explain such a case of "discontinuous evolution," because it is hard to imagine the position of the artery should have shifted through the muscle. The present investigation and the literature show that early in the embryonic development of a primate, man, and of Tupaia, both the arteria poplitea profunda and the arteria poplitea superficialis are present.

During pubertal development of the testes, germ cells pass initially through the complete succession of spermatogenic differentiation. Using the golden hamster as a model, this volume presents a comprehensive analysis of that establishing period of mammalian spermatogenesis. Detailed morphological and cell kinetic data of the pubertal seminiferous epithelium reveal a level of cellular organization and synchronization coming near to the adult situation. Characteristic, temporarily occurring perturbations of spermatogenic progression are related to specific delays of Sertoli or Leydig cell maturation, respectively. These results emphasize and specify the close structural and functional interdependence of germ and somatic cell development.

Glomerular flltration represents one of the basic mechanisms in the function of an organism. Our understanding of this process is still quite fragmentary. Regulation of blood flow and pressure, together with regulation of the ultraflltration coefficient (which is an attribute of the flltration barrier), are the two fundamental mechanisms accounting for maintenance and adaptability of glomerular flltration. Regulation of glomerular blood flow is generally considered to result from an interplay between afferent and efferent glomerular arterioles, and much progress has been made recently in understanding this interplay (Navar et al. 1996). The present study provides a detailed structural description of the glomerular vascular pole of rat. The results of this study appear to be relevant for several open questions of glomerular function. First, the interaction between afferent and efferent arterioles in regulating glomerular blood is generally understood to occur between the preglomerular and the postglomerular portions of these vessels. As shown in the present study, the structural elaborations of these arterioles and the spatial relationships between them within the glomerular hilum strongly suggest an interplay also at this site. Moreover, the current understanding of glomerular blood flow regulation by tuning the interplay between afferent and efferent arterioles is exclusively based on signals whose regulatory loops are established in follow-up events outside the glomerulus (tubuloglomerular balance, tubuloglomerular feedback).

Covering the psychological aspects of ergonomics, this volume places considerable emphasis on the radical changes in work practices over the past twenty years stimulated by high technology systems and computerization. Ergonomics is a multidisciplinary activity concerned mainly with people at work, but also with other human purposeful activities such as war, sports, games and leisure. The objective of ergonomics is to make these activities more effective and safer by applying established principles of anatomy, physiology and psychology. Together with Singleton's earlier volume, The Body at Work, this book forms a comprehensive textbook of ergonomics. This is a useful text for undergraduate and graduate students of psychology, physiology, management, social sciences, engineering, industrial design, computer science and information technology.

The cestodes, or tapeworms, are a group of parasitic worms many species of which cause serious, often fatal, diseases in man and domestic animals throughout the world. This book is an updated and expanded version of Professor Smyth's The Physiology of Cestodes (1969). The text has now been entirely rewritten, taking into account advances in investigative techniques such as immunocytochemistry, in vitro culture and scanning electron microscopy, which have immensely increased our understanding of these organisms. The biochemical coverage now includes the spectacular advances in molecular biology that have occured. The book also shows how cestodes are increasingly being recognized as valuable models for investigating fundamental biological phenomena such as membrane transport and asexual/sexual differentiation. Students of medicine, veterinary medicine, parasitology and zoology will find this book invaluable. Its high research content and extensive references also make it an essential reference book for researchers in these fields.

1.1 Overview The precise knowledge of the three-dimensional (3-D) assembly of biological structures is still in its origin. As an example, a widely accepted concept and common belief of the structure of the airway network oflung is that of a regular, dichotomous branching pattern, also known as the trumpet model. This model, first introduced by Weibel in 1963, is often used in clinical and physiological applications. However, if this concept of dichotomy is used to model lung, a shape is obtained that is quite different from a real lung. As a matter of fact, many previous quantitative morphological and stereological investigations of lung did not concentrate on the spatial aspect of lung morphology but delivered data in a more statistical fashion. Accordingly, the functional behavior predicted by such a model becomes questionable and indeed, the morphometrically predicted lung capacity exceeds the physiological required capacity by a factor of 1.3 up to a factor of2. This problem has also been termed a paradox, as discussed by Weibel in 1983. In the rare cases where descriptive models of the mammalian bronchial tree exist, monopodial in small mammals, dichotomous in larger ones, the understanding of the historical and/or functional reasons for size-related changes in the general design is not explainable. This investigation is trying to overcome this gap by computer modeling and functional simulation.

Cell culture techniques allow a variety of molecular and cell biological questions to be addressed, offering physiological conditions whilst avoiding the use of laboratory animals. In addition to basic techniques, a wide range of specialised practical protocols covering the following areas are included: cell proliferation and death, in-vitro models for cell differentiation, in-vitro models for toxicology and pharmacology, industrial application of animal cell culture, genetic manipulation and analysis of human and animal cells in culture.

Conditioned taste aversion (CTA) is a robust defence device protecting animals against repeated consumption of toxic food. It is characterised by the ability of many animals to learn to avoid certain substances by their sight, smell, or taste after experiencing an unpleasant or harmful reaction to them. CTA is encountered at all levels of evolution, with similar forms of food aversion learning found in vertebrate and invertebrate species whose ancestral lines diverged more than 500 million years ago. CTA has a number of unusual properties contrasting sharply with the basic assumptions of traditional learning theories, which has brought it increasingly to the attention of neurobiologists interested in neural plasticity. In CTA, the usual time parameters between stimulus and aversion are relaxed considerably, frequently with delays of hours rather than seconds. Moreover, the critical stage of CTA acquisition may proceed under deep anaesthesia incompatible with other forms of learning. In the past decade several pivotal discoveries have considerably avanced our understanding of the neural processes underlying CTA, and opened new possibilities for their analysis at the molecular and cellular levels. This book, written by three of the world's leading researchers in the subject, comprehensively reviews the current state of research into conditioned taste aversion. The first book of its kind to provide an up-to-date summary of research into the neuroanatomy, pharmacology, electrophysiology, and functional morphology of CTA, it will be welcomed by all researchers and graduate students in the field.

According to Jones and Smith (1973) the potential adverse effect of maternal alcoholism on the development of the offspring has been referred to in early Greek and Roman mythology. In a Carthaginian ritual, the bridal couple was forbidden to drink wine on their wedding night in order that defective children might not be conceived (Haggard and Jellinek 1942). Also, according to lones and Smith (1973,1975), the British House of Commons indicated in 1834, in a report by a select committee investigating drunk enness, that infants born to alcoholic mothers sometimes had a starved, shrivelled and imperfect look. According to Librizzi (1982) the first documented observations appeared in 1849 with the publication of the essay by Carpenter entitled "The Use and Abuse of Alcoholic Liquors in Health and Disease." He stated that habitual intemperance is the most potent of all causes of insanity because it aggravates the operation in other causes. Sullivan (1990) recorded increased abortion and stillbirth rates among chronically al coholic mothers in a Liverpool prison and an increased incidence of epilepsy in their surviving offspring. Various investigators including Ladraque (1901), Roe (1944). Le comte (1950), Christiaens et al. (1960) and Lemoine et al. (1967) have since then reported increased incidence of abnormalities and decreased weight of surviving children born to chronic alcoholic mothers."

What is it that stops the process of eating? This deceptively simple question lies at the centre of Satiation: From Gut to Brain, and the book succeeds in answering it comprehensively while incorporating the latest scientific research. Unless we stop eating by choice-for medical or social reasons-an unconscious physiological process is triggered through negative feedback from ingested food as it travels from the mouth through the stomach and on to the small intestine. This process is called satiation. Recent scientific evidence has revealed that food stimuli activate this process before the actual absorption of digested food, which significantly changes the traditional perspective that satiation depends on the post-absorptive repletion of metabolic fuels. This volume presents the first detailed account of the neurobiological mechanisms of satiation. The ten chapters of the book detail the neural, endocrine, and cellular underpinnings of the process. Authors expert in different aspects of satiation have compiled a critical overview of recent advances and current problems in this field. The inclusion of a chapter on the satiation of alcohol is unique in a book on food intake, and shows the convergence of ideas on satiation in these two areas. Comprehensive in scope and accessible to a wide array of advanced students and professonals, Satiation: From Gut to Brain is an authoritative and up-to-date review of every aspect of this important physiological process. Although intended primarily for neuroscientists, nutritionists, and psychobiologists, who will find it most pertinent to their work, the book will also be useful for physiologists, pharmacologists, and psychologists concerned with eating and its disorders.

3* Doody's Star Rating (R) CHOICE Magazine 'Recommended' (May 2020) As of 2018, pet obesity in the US affects an estimated 55.8 percent of dogs and 59.5 percent of cats, resulting in secondary conditions such as arthritis, diabetes mellitus, kidney disease, and certain forms of cancer. A complete and balanced diet accompanied by regular exercise is fundamental to optimize health and longevity in companion animals, meaning overweight pets have reduced quality of life and shorter life expectancy. Seeking to address this major modern-day problem, this book provides a comprehensive review of obesity in small animal medicine. Reviews epidemiology and how animal- and human-specific factors contribute to excess weight gain. Discusses the metabolic effects and inflammatory mediators associated with adiposity. Looks at various disease states and how they relate or develop as a result of obesity. Reviews different modalities to determine body composition to diagnose obesity. Offers a clinical approach to managing obesity with diet including discussion on the nutrients of concern for therapeutic weight loss diets. Veterinarians seeking to provide weight management services in practice will find clinically-applicable information from expert authors from both academic and practice backgrounds. Chapters cover topics ranging from epidemiology and pathophysiology of obesity to evaluation of body composition, and nutritional and behavioral management. The book also explores the role of exercise in managing obesity and looks at the management of co-morbidities. Finally, the authors present a range of case studies to demonstrate these topics in real-life practice.

This book draws together, for the first time, the published research on the behaviour, ecology and welfare of elephants living in zoos, circuses, logging camps and other captive environments in a single comprehensive volume. It takes a multi-disciplinary approach, considering the work of zoo biologists, animal behaviour and welfare scientists, veterinarians, philosophers, zoo educators, tourism specialists, conservation biologists, lawyers and others with a professional interest in elephants. Elephants under Human Care: The Behaviour, Ecology, and Welfare of Elephants in Captivity is a valuable resource for zoo biology and animal welfare researchers. It is also useful for students and zoo professionals and managers looking for a comprehensive guide to current research on captive elephants. Although not intended as a husbandry manual, the book discusses some of the elephant welfare standards developed by the Association of Zoos and Aquariums (AZA) and the British and Irish Association of Zoos and Aquariums (BIAZA) and their relationship to current knowledge of captive elephants.

The value of the canine nose is well-documented, and working dogs are being utilized for their olfactory skills in an increasing number of fields. Not only are dogs used by police, security, and the military, but they are also now used in forensic science, in medical detection of disease, in calculating population trends of endangered species and eradicating invasive species in protected environments, and in identifying infestations and chemical contaminants. Edited and contributed to by eminent scholars, Canine Olfaction Science and Law: Advances in Forensic Science, Medicine, Conservation, and Environmental Remediation takes a systematic scientific approach to canine olfaction. It includes work from scientists working in pure and applied disciplines, trainers and handlers who have trained and deployed detection dogs, and lawyers who have evaluated evidence produced with the aid of detection and scent identification dogs. The book is divided into six sections covering The anatomy, genetics, neurology, and evolution of canine olfaction as well as diseases affecting it The chemistry and aerodynamics of odors Behavior, learning, and training Uses of canine olfaction in forensics and law Uses in conservation and remediation Uses in detection of diseases and medical conditions The various contributors describe cutting edge research, some conclusions of which are the subject of vigorous debates between various laboratories and researchers. The editors have added cross-references so that readers can consider the different perspectives that are currently being advanced and understand where consensus is being built and where more research needs to be done. A useful practical reference, Canine Olfaction Science and Law provides a wealth of information beneficial to a wide range of disciplines. It aids trainers and handlers of detection dogs as well as various professionals in healthcare, law enforcement, forensic science, and environmental conservation to gain a better understanding of the remarkable power of the canine nose while encouraging further advances in applications.

In this, our second edition of Reproduction in Mammals, we are responding to numerous requests for a more up-to-date and rather more detailed treatment of the subject. The first edition was accorded an excellent reception, but Books 1 to 5 were written some 14 years ago and inevitably there have been many advances on many fronts since then. As before, the manner of presentation is intended to make the subject matter interesting to read and readily comprehensible to undergraduates in the biological sciences, and yet with sufficient depth to provide a valued source of information to graduates engaged in both teaching and research. Our authors have been selected from among the best known in their respective fields. Book 5 is concerned with the many ways in which we can now manipulate reproductive processes in animals and humans, thanks to our new understanding of hormone action and improved control over early developmental events. We have at our disposal a whole array of synthetic hormone agonists, antagonists and antibodies that can be used at will to stimulate or inhibit fertility in animals and humans alike, so that productivity in livestock can be promoted according to plan and child-bearing becomes more a matter of choice than chance. We can compensate for infertility by in vitro fertilization and embryo transfer, and overcome inherent deficiencies by techniques involving embryo manipulation. Existing barriers to the dissemination and application of this new-found knowledge are discussed in some detail, since it is becoming increasingly clear that improvements in the quality of life for people in many developing countries will be long delayed unless they can meet essential needs and call a halt to runaway population growth.

The book shows that cell membranes vary according to the 24h cycle: it deals with circadian changes in membrane composition, principally the plasma membrane and with structural organization changes in some chloroplast thylakoids. The book deals with changes in activity or efficiency of pumps, channels, photo- and hormone receptors, in sensitivity towards external signals, in sensitivity to some drugs, including anaesthetics and in changes in signal transduction. The cell cycle is discussed on theoretical and experimental grounds, as well as its gating by circadian rhythmicity. The rhythm generating mechanism is modelized. The circadian oscillation of the plasma membrane confers a temporal parameter.

1. 1 Objectives of this Study The vertebrate middle ear has attracted the interest of morphologists for more than a century. Its difficult structure, its complicated evolutionary derivation, and its integration of branchial, cranial, and otic materials into a single func- tional unit have made it a key organ for the understanding of vertebrate structures and their evolutionary history. Gaupp's (1898, 1913) and Reichert's (1837) comparative morphological studies of the vertebrate middle ear repre- sented milestones for anatomy in the general recognition and acceptance of Darwin's theory of evolution. These fundamental studies notwithstanding, today's knowledge of avian middle ear structures is still characterized by descriptive studies focusing on character sampling to elucidate high-level phylogeny. Phylogenetic studies have considered either structural aspects of the bony stapes exclusively (Feduccia 1974, 1975a,b, 1976, 1977, 1978), or focused on the anatomy of the middle ear cavity, neglecting the sound trans- mission apparatus (Saiff 1974, 1976, 1978a,b, 1981, 1982, 1983, 1988). Other studies have investigated late-stage embryos and concentrated on the develop- ment of the skull, considering middle ear structures only as a side aspect. However, there are considerable structural differences between the middle ears of late-stage embryos, hatchlings, and adults of the same species. Although vertebrate morphology requires a meticulous knowledge of comparative middle ear data and calls upon an elaborate system of homologies, it turns out that knowledge of middle ear structural details is widely dispersed among different species and different developmental stages, making a comparison even more difficult.

1. 1 Purpose and Plan of This Review This review is focused on the topography and connections of some of the neuron populations that determine the manual dexterity of the macaque monkey. The populations selected for examination are the following: 1. The corticospinal neuron populations 2. The thalamocortical and corticothalamic neuron populations associated with the sensorimotor cortex 3. The ipsilateral cortical connections of the sensorimotor cortex These neuron populations have been chosen because of their obvious rel evance to the directed, intelligent use of the hands, but also because of their anatomical and functional interdependence. Corticospinal neuron populations transmit a complex, orchestrated output from a number of different regions of cerebral cortex to the neuron populations in every segment of the spinal cord, and this output includes the command information defining the intended manual action. The thalamocortical complex is especially concerned with the transmis sion and modulation or filtering of (a) visual, tactile, proprioceptive, vestibular, and auditory information to the cerebral cortex and (b) information from the cerebellum, basal ganglia, limbic system, and brain stem which is relevant to sensorimotor behavior. Finally, the extensive ipsilateral cortical connections constitute a major part of the supraspinal circuitry which coordinates the contri butions of all the cortical neuron popUlations contributing to intelligent sen sorimotor behavior and, in particular, transmits the cross talk between those cortical neuron populations which shape and control the dextrous handling of objects within reach.

It is generally recognized that larger animals eat more, live longer, have larger offspring, and so on; but it is unusual to see these commonplace observations as a basis for scientific biology. A large number of empirically based relationships describe biological rates as simple functions of body size; and other such relations predict the intrinsic rate of population growth, animal speed, animal density, territory size, prey size, physiology, and morphology. Such equations almost always exist for mammals and birds, often for other vertebrates and invertebrates, sometimes for protozoa, algae, and bacteria, and occasionally even for plants. There are too many organisms to measure all aspects of the biology of every species of population, so scientists must depend on generalizations. Body size relations represent our most extensive and powerful assemblage of generalizations, but they have never been organized for use in ecology. This book represents the largest single compilation of interspecific size relations, and instructs the reader on the use of these relationships; their comparison, combination, and criticism. Both strengths and weaknesses of our current knowledge are discussed in order to indicate the many possible directions for further research. This important volume will therefore provide a point of departure toward a new applied ecology, giving quantitative solutions to real questions. It will interest advanced students of ecology and comparative physiology as well as professional biologists.

Experimental Hydrodynamics of Fast-Floating Aquatic Animals presents the latest research on the physiological, morphological and evolutionary factors in aquatic animal locomotion. Beginning with an overview on how to conduct experiments on swimming aquatic animals, assessing hydrodynamic forces, resistance and geometric parameters of animal bodies, the book then details how aquatic animals, such as fast-moving dolphins, can achieve high speeds without over-expelling their energy resources. It provides insights into investigations on how animals, including dolphins, sharks and swordfish can maneuver through water at high speeds, offering a natural model for improving human and technological underwater locomotion. This book is essential for researchers and practicing biologists interested in the study of aquatic animal locomotive physiology and its application to human technology. Advanced undergraduate and graduate students will also find this a helpful academic resource for further understanding animal hydrodynamics.

Reveals how the physical laws of nature control the physiological functions of all animals and influence their size. Shows why the size of living things is of such fundamental importance.