Circadian Rhythms And The Human

Circadian Rhythms and the Human covers the basic principles behind the human circadian rhythms. This book is composed of 12 chapters that discuss the detection, analysis, and definition of rhythms, specifically exogenous and endogenous rhythms. This book also demonstrates the mechanism of metabolic and gastrointestinal rhythms. The opening chapters deal with the rhythms in living organism; establishing the endogeneity of rhythms; definition of nychthemeral rhythm; methods of measuring the frequency of rhythms; exogenous effects upon the temperature rhythm; interaction between exogenous and endogenous influences; and possible origins of renal rhythmicity. The succeeding chapters consider the effect of exercise at different times of day and the concept of sleep-wakefulness rhythm. The discussion then shifts to the effects of repeated time-zone transitions and the effects of time on drug administration. The closing chapters are devoted to the assessment of work performance during shift work. The book can provide useful information to doctors, students, researchers, and the general reader.

Circadian Rhythms and the Human.

Biological rhythmicity has been a subject of scientific research for a relatively short time. In the special case of daily, or circadian rhythms, it is only during the past twenty years that rapidly increasing efforts have been undertaken in evaluat ing properties and mechanisms. As a consequence of these efforts, the study of biological and, in particular, circadian rhythmicity is no longer a somewhat dubious occupation but rather a serious branch of science which combines the interdisciplinary efforts of numerous researchers around the world. The general result of these efforts is that many features of circadian rhythms of many different species of living beings are well known today. In addition to studies with lower organisms, the evaluation of human circadian rhythms was originally more or less a compulsory exercise done in order to extend the "catalogue of species"; of course, the work was of unusual impor tance due to the special position of man in biology. In the course of the very first experimental series, it became clear that humans possess an "internal clock" as had been established in various organisms, protists, plants, and animals, and that human circadian rhythms fit the general regularities of biological rhythms known at that time. However, it soon became apparent that circadian rhythmicity of man shows, additionally, particularities of great general interest, for practical and theoretical reasons.

With the invitation to edit this volume, I wanted to take the opportunity to assemble reviews on different aspects of circadian clocks and rhythms. Although most c- tributions in this volume focus on mammalian circadian clocks, the historical int- duction and comparative clocks section illustrate the importance of various other organisms in deciphering the mechanisms and principles of circadian biology. Circadian rhythms have been studied for centuries, but only recently, a mole- lar understanding of this process has emerged. This has taken research on circadian clocks from mystic phenomenology to a mechanistic level; chains of molecular events can describe phenomena with remarkable accuracy. Nevertheless, current models of the functioning of circadian clocks are still rudimentary. This is not due to the faultiness of discovered mechanisms, but due to the lack of undiscovered processes involved in contributing to circadian rhythmicity. We know for example, that the general circadian mechanism is not regulated equally in all tissues of m- mals. Hence, a lot still needs to be discovered to get a full understanding of cir- dian rhythms at the systems level. In this respect, technology has advanced at high speed in the last years and provided us with data illustrating the sheer complexity of regulation of physiological processes in organisms. To handle this information, computer aided integration of the results is of utmost importance in order to d- cover novel concepts that ultimately need to be tested experimentally.

The earth's daily rotation affects just about every living creature. From dawn through to dusk, there are changes in light, temperature, humidity, and rainfall. However, these changes are regular, rhythmic and, therefore, predictable. Thus, the near 24 hour circadian rhythm is innate: a genetically programmed clock that essentially ticks of its own accord. This Very Short Introduction explains how organisms can "know" the time and reveals what we now understand of the nature and operation of chronobiological processes. Covering variables such as light, the metabolism, human health, and the seasons, Foster and Kreitzman illustrate how jet lag and shift work can impact on human well-being, and consider circadian rhythms alongside a wide range of disorders, from schizophrenia to obesity. ABOUT THE SERIES: The Very Short Introductions series from Oxford University Press contains hundreds of titles in almost every subject area. These pocket-sized books are the perfect way to get ahead in a new subject quickly. Our expert authors combine facts, analysis, perspective, new ideas, and enthusiasm to make interesting and challenging topics highly readable.

Popular science at its most exciting: the breaking new world of chronobiology - understanding the rhythm of life in humans and all plants and animals. The entire natural world is full of rhythms. The early bird catches the worm -and migrates to an internal calendar. Dormice hibernate away the winter. Plants open and close their flowers at the same hour each day. Bees search out nectar-rich flowers day after day. There are cicadas that can breed for only two weeks every 17 years. And in humans: why are people who work anti-social shifts more illness prone and die younger? What is jet-lag and can anything help? Why do teenagers refuse to get up in the morning, and are the rest of us really 'larks' or 'owls'? Why are most people born (and die) between 3am-5am? And should patients be given medicines (and operations) at set times of day, because the body reacts so differently in the morning, evening and at night? The answers lie in our biological clocks the mechanisms which give order to all living things. They impose a structure that enables us to change our behaviour in relation to the time of day, month or year. They are reset at sunrise and sunset each day to link astronomical time with an organism's internal time.

Circadian clocks are endogenous and temperature-compensating timekeepers that provide temporal organization of biological processes in living organisms. Circadian rhythms allow living organisms to adapt to the daily light cycles associated with Earth's rotation and to anticipate and prepare for precise and regular environmental changes. This book discusses the fundamental advances of how the circadian clock regulates critical biological functions as well as the cellular and molecular mechanisms controlling circadian rhythm in living organisms. It also provides new insights into and sheds new light on the current research trends and future research directions related to circadian rhythm. This book provokes interest in many readers, researchers and scientists, who can find this information useful for the advancement of their research works towards a better understanding of circadian rhythm regulatory mechanisms.