Download Free Human Skeletal Muscle Oxygenation And Perfusion Book in PDF and EPUB Free Download. You can read online Human Skeletal Muscle Oxygenation And Perfusion and write the review.

This presentation describes various aspects of the regulation of tissue oxygenation, including the roles of the circulatory system, respiratory system, and blood, the carrier of oxygen within these components of the cardiorespiratory system. The respiratory system takes oxygen from the atmosphere and transports it by diffusion from the air in the alveoli to the blood flowing through the pulmonary capillaries. The cardiovascular system then moves the oxygenated blood from the heart to the microcirculation of the various organs by convection, where oxygen is released from hemoglobin in the red blood cells and moves to the parenchymal cells of each tissue by diffusion. Oxygen that has diffused into cells is then utilized in the mitochondria to produce adenosine triphosphate (ATP), the energy currency of all cells. The mitochondria are able to produce ATP until the oxygen tension or PO2 on the cell surface falls to a critical level of about 4–5 mm Hg. Thus, in order to meet the energetic needs of cells, it is important to maintain a continuous supply of oxygen to the mitochondria at or above the critical PO2 . In order to accomplish this desired outcome, the cardiorespiratory system, including the blood, must be capable of regulation to ensure survival of all tissues under a wide range of circumstances. The purpose of this presentation is to provide basic information about the operation and regulation of the cardiovascular and respiratory systems, as well as the properties of the blood and parenchymal cells, so that a fundamental understanding of the regulation of tissue oxygenation is achieved.
The aim of this treatise is to summarize the current understanding of the mechanisms for blood flow control to skeletal muscle under resting conditions, how perfusion is elevated (exercise hyperemia) to meet the increased demand for oxygen and other substrates during exercise, mechanisms underlying the beneficial effects of regular physical activity on cardiovascular health, the regulation of transcapillary fluid filtration and protein flux across the microvascular exchange vessels, and the role of changes in the skeletal muscle circulation in pathologic states. Skeletal muscle is unique among organs in that its blood flow can change over a remarkably large range. Compared to blood flow at rest, muscle blood flow can increase by more than 20-fold on average during intense exercise, while perfusion of certain individual white muscles or portions of those muscles can increase by as much as 80-fold. This is compared to maximal increases of 4- to 6-fold in the coronary circulation during exercise. These increases in muscle perfusion are required to meet the enormous demands for oxygen and nutrients by the active muscles. Because of its large mass and the fact that skeletal muscles receive 25% of the cardiac output at rest, sympathetically mediated vasoconstriction in vessels supplying this tissue allows central hemodynamic variables (e.g., blood pressure) to be spared during stresses such as hypovolemic shock. Sympathetic vasoconstriction in skeletal muscle in such pathologic conditions also effectively shunts blood flow away from muscles to tissues that are more sensitive to reductions in their blood supply that might otherwise occur. Again, because of its large mass and percentage of cardiac output directed to skeletal muscle, alterations in blood vessel structure and function with chronic disease (e.g., hypertension) contribute significantly to the pathology of such disorders. Alterations in skeletal muscle vascular resistance and/or in the exchange properties of this vascular bed also modify transcapillary fluid filtration and solute movement across the microvascular barrier to influence muscle function and contribute to disease pathology. Finally, it is clear that exercise training induces an adaptive transformation to a protected phenotype in the vasculature supplying skeletal muscle and other tissues to promote overall cardiovascular health. Table of Contents: Introduction / Anatomy of Skeletal Muscle and Its Vascular Supply / Regulation of Vascular Tone in Skeletal Muscle / Exercise Hyperemia and Regulation of Tissue Oxygenation During Muscular Activity / Microvascular Fluid and Solute Exchange in Skeletal Muscle / Skeletal Muscle Circulation in Aging and Disease States: Protective Effects of Exercise / References
This dissertation examined the effect of skeletal muscle stretching on central and peripheral cardiovascular responses in humans. Healthy males performed controlled passive stretching at three different stretching intensities of the plantar flexors on an isokinetic dynamometer. To determine how stretching effects peripheral cardiovascular parameters of muscle blood flow and perfusion of the popliteal artery, Doppler ultrasound velocimetry and imaging techniques were used to determine mean blood flow (MBF), antegrade blood flow and retrograde blood flow responses while near infrared spectroscopy (NIRS) was used to measure changes in muscle tissue oxygen extraction (deoxygenated hemoglobin; [HHb]) and blood volume (total hemoglobin+myoglobin; (Hbtot). To determine how stretching effects central cardiovascular parameters, heart rate (HR) was measured using electrocardiography and finger photoplethysmography was used to measure mean arterial pressure (MAP) simultaneous to peripheral cardiovascular responses. During each stretching session a significant elevation in antegrade and retrograde blood flow were observed, whereas MBF responses were not significantly altered suggesting that skeletal muscle stretching in humans does not alter blood flow but can cause a dramatic change in the biphasic nature of the blood flow responses. NIRS-derived estimates of [HHb] and [Hbtot] were significantly increased, suggesting that skeletal muscle stretching in humans increases muscle metabolism. Heart rate significantly rose in a stretch intensity- and time-dependent manner, whereas blood pressure was not significantly altered, suggesting a role for mechanoreceptive afferent feedback arising from the musculature to initiate rapid adjustments in blood flow control. After each stretching session a significant elevation in [Hbtot], MBF and antegrade blood flow responses were observed in each stretching condition, suggesting that stretching creates a post-stretch hyperemic response in humans. The retrograde blood flow responses were significantly decreased following each stretching session and these responses remained depressed at every time interval measured, suggesting that stretching in humans creates a lower level of resting myogenic tone and reduced downstream vascular resistance. These changes were also marked by significant decreases in MAP in a muscle stretching-extent dependent manner suggesting that: 1) skeletal muscle stretching in humans (afterward) mediates a baroreflex that serves to adjust central (HR and BP) parameters back to normal and 2) the magnitude of the stretch (i.e. higher intensity stretches) appear to dictate this response. Collectively, the data acquired from this investigation has examined and verified a critical role for skeletal muscle stretching and cardiovascular responses. Moreover, the reductions in BP and retrograde blood flow seen after stretching suggests that skeletal muscle stretching in humans reduces myogenic vascular tone which may confer additional beneficial vascular effects in a post-stretch resting period. Alterations in NIRS-derived microvascular parameters may reveal a causal role for this phenomenon which serves to regulate how the upstream conduit artery blood flow profiles manifest.
Research centering on blood flow in the heart continues to hold an important position, especially since a better understanding of the subject may help reduce the incidence of coronary arterial disease and heart attacks. This book summarizes recent advances in the field; it is the product of fruitful cooperation among international scientists who met in Japan in May, 1990 to discuss the regulation of coronary blood flow.
The two previous editions of Applied Physiology in Intensive Care Medicine proved extremely successful, and the book has now been revised and split into two volumes to enhance ease of use. In this second volume some of the most renowned experts in the field offer detailed reviews on measurement techniques and physiological processes of crucial importance in intensive care medicine. Throughout, a key aim is to help overcome the fundamental unevenness in clinicians’ understanding of applied physiology, which can lead to suboptimal treatment decisions. Applied Physiology in Intensive Care has been written by some of the most renowned experts in the field and provides an up-to-date compendium of practical bedside knowledge essential to the effective delivery of acute care medicine. It will serve the clinician as an invaluable reference source on key issues regularly confronted in everyday practice.
It is a commonly held belief that athletes, particularly body builders, have greater requirements for dietary protein than sedentary individuals. However, the evidence in support of this contention is controversial. This book is the latest in a series of publications designed to inform both civilian and military scientists and personnel about issues related to nutrition and military service. Among the many other stressors they experience, soldiers face unique nutritional demands during combat. Of particular concern is the role that dietary protein might play in controlling muscle mass and strength, response to injury and infection, and cognitive performance. The first part of the book contains the committee's summary of the workshop, responses to the Army's questions, conclusions, and recommendations. The remainder of the book contains papers contributed by speakers at the workshop on such topics as, the effects of aging and hormones on regulation of muscle mass and function, alterations in protein metabolism due to the stress of injury or infection, the role of individual amino acids, the components of proteins, as neurotransmitters, hormones, and modulators of various physiological processes, and the efficacy and safety considerations associated with dietary supplements aimed at enhancing performance.
Respiratory Muscle Training: theory and practice is the world’s first book to provide an "everything-you-need-to-know" guide to respiratory muscle training (RMT). Authored by an internationally-acclaimed expert, it is an evidence-based resource, built upon current scientific knowledge, as well as experience at the cutting-edge of respiratory training in a wide range of settings. The aim of the book is to give readers: 1) an introduction to respiratory physiology and exercise physiology, as well as training theory; 2) an understanding of how disease affects the respiratory muscles and the mechanics of breathing; 3) an insight into the disease-specific, evidence-based benefits of RMT; 4) advice on the application of RMT as a standalone treatment, and as part of a rehabilitation programme; and finally, 5) guidance on the application of functional training techniques to RMT. The book is divided into two parts – theory and practice. Part I provides readers with access to the theoretical building blocks that support practice. It explores the evidence base for RMT as well as the different methods of training respiratory muscles and their respective efficacy. Part II guides the reader through the practical implementation of the most widely validated form of RMT, namely inspiratory muscle resistance training. Finally, over 150 "Functional" RMT exercises are described, which incorporate a stability and/or postural challenge – and address specific movements that provoke dyspnoea. Respiratory Muscle Training: theory and practice is supported by a dedicated website (www.physiobreathe.com), which provides access to the latest information on RMT, as well as video clips of all exercises described in the book. Purchasers will also receive a three-month free trial of the Physiotec software platform (via www.physiotec.ca), which allows clinicians to create bespoke training programmes (including video clips) that can be printed or emailed to patients. Introductory overviews of respiratory and exercise physiology, as well as training theory Comprehensive, up-to-date review of respiratory muscle function, breathing mechanics and RMT Analysis of the interaction between disease and respiratory mechanics, as well as their independent and combined influence upon exercise tolerance Analysis of the rationale and application of RMT to over 20 clinical conditions, e.g., COPD, heart failure, obesity, mechanical ventilation Evidence-based guidance on the implementation of inspiratory muscle resistance training Over 150 functional exercises that incorporate a breathing challenge www.physiobreathe.com - access up-to-date information, video clips of exercises and a three-month free trial of Physiotec’s RMT exercise module (via www.physiotec.ca)
From the 39th annual conference of the International Society on Oxygen Transport to Tissue (ISOTT), held in Washington, DC, USA in July 2011, this volume covers aspects of oxygen transport from air to the cells, organs and organisms; instrumentation and methods to sense oxygen and clinical evidence. Oxygen Transport to Tissue XXXIV includes contributions from scientists (physicists, biologists and chemists), engineers, clinicians and mathematicians.