Regulation of Tissue Oxygenation, Second Edition
Regulation of Tissue Oxygenation, Second Edition

Author: Roland N. Pittman

Publisher: Biota Publishing

Published: 2016-08-18

Total Pages: 117

ISBN-13: 1615047212

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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.

Tissue Oxygen Utilization
Tissue Oxygen Utilization

Author: Guillermo Gutierrez

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 381

ISBN-13: 3642841694

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Disturbances in peripheral O extraction can be produced in dogs treated with 2 endotoxin and thereby provide an opportunity to test theories for the origin of pathological O supply dependency or to try different treatment modalities. The 2 most serious deficiency in the current animal models is the inability to mimic the increased O demand that is observed in patients at 02 delivery rates in excess of 2 normal. A particular feature of this increased O demand is that it apparently does 2 not stimulate increased 02 extraction, although the limitation in O extraction has 2 not been explored in patients by lowering 02 supply, for obvious reasons. At least two possibilities to account for increased 02 demand could be investigated in animal models, however. The amount of 02 that is utilized in extramitochondrial pathways, which is normally on the order of 10%, may be greatly increased in ARDS and sepsis by O radical formation. There is presently no information 2 concerning how much 02 might be used in this way. Another strong possibility is that mitochondrial injury, perhaps as a result of 02 radical formation, uncouples oxidative phosphorylation. Some evidence presently in the literature supports this idea [19]. Indeed, the association of increased blood lactate levels with higher than expected 02 demands makes uncoupling a very attractive hypothesis that warrants further investigation in animal models using such agents as 2,4-dinitrophenol. References 1.

Skeletal Muscle Circulation
Skeletal Muscle Circulation

Author: Ronald J. Korthuis

Publisher: Morgan & Claypool Publishers

Published: 2011

Total Pages: 147

ISBN-13: 1615041834

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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

Oxygen Transport to Tissue XXXII
Oxygen Transport to Tissue XXXII

Author: Joseph C. LaManna

Publisher: Springer Science & Business Media

Published: 2011-03-29

Total Pages: 371

ISBN-13: 1441977562

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This book covers all aspects of oxygen delivery to tissue, including blood flow and its regulation as well as oxygen metabolism. Special attention will be paid to methods of oxygen measurement in living tissue and application of these technologies to understanding physiological and biochemical basis for pathology related to tissue oxygenation. This book is multidisciplinary and designed to bring together experts and students from a range of research fields including biochemical engineering, physiology, microcirculation, and hematology.

Control of Cardiac Output
Control of Cardiac Output

Author: David Young

Publisher: Biota Publishing

Published: 2010-01-01

Total Pages: 110

ISBN-13: 1615040226

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Although cardiac output is measured as the flow of blood from the left ventricle into the aorta, the system that controls cardiac output includes many other components besides the heart itself. The heart’s rate of output cannot exceed the rate of venous return to it, and therefore, the factors governing venous return are primarily responsible for control of output from the heart. Venous return is affected by its pressure gradient and resistance to flow throughout the vascular system. The pressure gradient for venous return is a function of several factors including the blood volume flowing through the system, the unstressed vascular volume of the circulatory system, its capacitance, mean systemic pressure, and right atrial pressure. Resistance to venous return is the sum of total vascular resistance from the aortic valve to the right atrium. The sympathetic nervous system and vasoactive circulating hormones affect short-term resistance, whereas local tissue blood flow autoregulatory mechanisms are the dominant determinants of long-term resistance to venous return. The strength of contraction of the heart responds to changes in atrial pressure driven by changes in venous return, with small changes in atrial pressure eliciting large changes in strength of contraction, as described by the Frank–Starling mechanism. In addition, the autonomic nervous system input to the heart alters myocardial pumping ability in response to cardiovascular challenges. The function of the cardiovascular system is strongly affected by the operation of the renal sodium excretion–body fluid volume–arterial pressure negative feedback system that maintains arterial blood pressure at a controlled value over long periods. The intent of this volume is to integrate the basic knowledge of these cardiovascular system components into an understanding of cardiac output regulation. Table of Contents: Introduction / Venous Return / Cardiac Function / Integrated Analysis of Cardiac Output Control / Analysis of Cardiac Output Regulation by Computer Simulation / Analysis of Cardiac Output Control in Response to Challenges / Conclusion / References / Author Biography

Regulation of Coronary Blood Flow
Regulation of Coronary Blood Flow

Author: Michitoshi Inoue

Publisher: Springer Science & Business Media

Published: 2013-11-09

Total Pages: 330

ISBN-13: 4431683674

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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.

Common Surgical Diseases
Common Surgical Diseases

Author: Jonathan A. Myers

Publisher: Springer Science & Business Media

Published: 2013-03-14

Total Pages: 527

ISBN-13: 1475729456

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In a concise manner, this book presents common surgical problems encountered by medical students and residents. The book provides easy access for residents before teaching rounds, lectures, etc. The algorithm approach lends itself to rapid learning, making the book a must for every surgical resident.

Oxygen Transport to Tissue XVI
Oxygen Transport to Tissue XVI

Author: Michael C. Hogan

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 627

ISBN-13: 146151875X

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Since its inception in 1973, The International Society on Oxygen Transport to Tissue (ISOTT) has provided a unique forum to facilitate and encourage scientific interaction and debate. Welcoming scientists and clinicians from a broad spectrum of disciplines, each with their own particular skills and expertise, ISOTT unites them under the common theme of oxygen transport. The successful blend of scientific presentations and informal discussion which characterizes ISOTT is epitomized best by the many fundamental discoveries and technical advancements which it has spawned. The breadth and strengths of The Society's scientific base promotes the rapid progression of ideas from theoretical concepts to rigorous scientific testing and often, ultimately to the clinical arena. Each publication of the ISOTT proceedings has been recognized by Science Citation Index listing and the papers frequently establish scientific precedents and become considered as standard works in their respective fields. The 21st ISOTT Meeting was held in San Diego from August 14th through August 18th, 1993. The San Diego Meeting attracted about 150 registrants and 40 accompanying persons. Ten state-of-the-art lectures were presented by international experts in ~ transport and there were in addition two symposia -one dealing with assessment of tissue hypoxia and the other with functional heterogeneity in different organ systems. There were 100 free communications, consisting of posters accompanied by an abbreviated oral summary. All manuscripts were reviewed by the Editors for form and content, but as is customary for the ISOTT proceedings, rigorous scientific peer review was not undertaken.