Inactivity: Physiological Effects

Inactivity: Physiological Effects describes the physiological deconditioning inherent in inactivity and immobilization. This book is organized into eight chapters that review the body of information from studies on healthy volunteers conducted in direct support of the space program. Considerable chapters are devoted to the changes occurring in the cardiovascular system, bone and muscle, metabolism and endocrine responses, psychosocial responses, and exercise tolerance. Other chapters discuss the clinical effects and clinical management of deterioration while indicating the changes that have been found in health, normal bed rested subjects. The remaining chapters explore the data on crews that have flown in since their physiological responses are qualitatively similar to those observed in bed rested subjects or immobilized patients on earth. Clinicians, nursing staff, physiologists, researchers, and students in the field will find this book invaluable.

Foreword Preface 1 Introduction I. Entry into the Space Age II. Ground-Based Simulations of Weightlessness III. Effects of Inactivity IV. The Effects of Gravity V. Summary References 2 Cardiovascular Effects of Inactivity I. The Impact of Gravity II. Levels of Defense in Body Position Changes III. The Gauer-Henry Reflex IV. Cardiovascular Responses to Inactivity and Immobilization V. Stress Test Responses following Inactivity VI. Cardiovascular Changes with Weightlessness VII. Management of Cardiovascular Effects of Inactivity VIII. Clinical Applications References 3 Effects of Inactivity on Bone and Calcium Metabolism I. Current Concepts of Skeletal Metabolism II. Current Concepts in Calcium Metabolism III. Negative Calcium Balance during Bed Rest IV. Changes in Blood Chemistries during Bed Rest V. Intestinal Calcium Absorption during Bed Rest VI. Renal Excretion of Calcium during Bed Rest VII. Influence of Age and Sex on Calciuria VIII. The Effect of Bed Rest on Bone Density IX. Effects of Immobilization on Bone Composition and Structure X. Effects of Exercise on Bone Loss during Bed Rest XI. Bone Loss during Spaceflight XII. Bone Changes in "Bed Rested" Animal Models XIII. Summary Reference 4 Effects of Inactivity on Muscle I. Muscles and Gravity II. Functional Anatomy III. Biochemistry of Muscle Contraction IV. Neural Control V. Effects of Exercise on Muscles VI. Disuse Atrophy of Muscle VII. Effects of Inactivity VIII. Spaceflight Findings IX. Management of Disuse Atrophy X. Diseases of Muscle Inactivity XI. Conclusions References 5 Metabolic and Endocrine Changes I. Metabolic Changes with Inactivity II. Post-Bed-Rest Orthostatic Hypotension and Countermeasures III. Drug Metabol