Download or read book Local Control of Microvascular Perfusion written by Michael Hill and published by Morgan & Claypool Publishers. This book was released on 2012 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: Local control of microvascular perfusion refers to the ability of individual tissues to maintain a relative constancy of hemodynamics in the face of changing perfusion pressure while meeting metabolic demands appropriately. The regulation of local blood flow, or autoregulation, and its underlying mechanisms have been a subject of considerable interest for over 100 years. Particular focus has been placed on the acute interaction of myogenic (pressure-induced) and metabolic (local production of vasodilator metabolites) parameters and how they interact with flow (shear stress)-dependent and conduction-based mechanisms to produce integrated local vascular network responses (for example, as seen during reactive and functional hyperemia). This monograph discusses each of these vasoregulatory phenomena while also considering evidence for their underlying cellular mechanisms. Further, an attempt is made to integrate the information into complex in vivo situations and consider their relevance to pathophysiological situations.
Download or read book Local Control of Microvascular Perfusion written by Michael Hill and published by Biota Publishing. This book was released on 2012-10-01 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: Local control of microvascular perfusion refers to the ability of individual tissues to maintain a relative constancy of hemodynamics in the face of changing perfusion pressure while meeting metabolic demands appropriately. The regulation of local blood flow, or autoregulation, and its underlying mechanisms have been a subject of considerable interest for over 100 years. Particular focus has been placed on the acute interaction of myogenic (pressure-induced) and metabolic (local production of vasodilator metabolites) parameters and how they interact with flow (shear stress)-dependent and conduction-based mechanisms to produce integrated local vascular network responses (for example, as seen during reactive and functional hyperemia). This monograph discusses each of these vasoregulatory phenomena while also considering evidence for their underlying cellular mechanisms. Further, an attempt is made to integrate the information into complex in vivo situations and consider their relevance to pathophysiological situations.
Download or read book The Cerebral Circulation written by Marilyn J. Cipolla and published by Biota Publishing. This book was released on 2016-07-28 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: This e-book will review special features of the cerebral circulation and how they contribute to the physiology of the brain. It describes structural and functional properties of the cerebral circulation that are unique to the brain, an organ with high metabolic demands and the need for tight water and ion homeostasis. Autoregulation is pronounced in the brain, with myogenic, metabolic and neurogenic mechanisms contributing to maintain relatively constant blood flow during both increases and decreases in pressure. In addition, unlike peripheral organs where the majority of vascular resistance resides in small arteries and arterioles, large extracranial and intracranial arteries contribute significantly to vascular resistance in the brain. The prominent role of large arteries in cerebrovascular resistance helps maintain blood flow and protect downstream vessels during changes in perfusion pressure. The cerebral endothelium is also unique in that its barrier properties are in some way more like epithelium than endothelium in the periphery. The cerebral endothelium, known as the blood-brain barrier, has specialized tight junctions that do not allow ions to pass freely and has very low hydraulic conductivity and transcellular transport. This special configuration modifies Starling's forces in the brain microcirculation such that ions retained in the vascular lumen oppose water movement due to hydrostatic pressure. Tight water regulation is necessary in the brain because it has limited capacity for expansion within the skull. Increased intracranial pressure due to vasogenic edema can cause severe neurologic complications and death.
Download or read book Regulation of Tissue Oxygenation Second Edition written by Roland N. Pittman and published by Biota Publishing. This book was released on 2016-08-18 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Regulation of Coronary Blood Flow written by Michitoshi Inoue and published by Springer Science & Business Media. This book was released on 2013-11-09 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Regulation of Endothelial Barrier Function written by Sarah Y. Yuan and published by Biota Publishing. This book was released on 2011-02-01 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: The vascular endothelium lining the inner surface of blood vessels serves as the first interface for circulating blood components to interact with cells of the vascular wall and surrounding extravascular tissues. In addition to regulating blood delivery and perfusion, a major function of vascular endothelia, especially those in exchange microvessels (capillaries and postcapillary venules), is to provide a semipermeable barrier that controls blood–tissue exchange of fluids, nutrients, and metabolic wastes while preventing pathogens or harmful materials in the circulation from entering into tissues. During host defense against infection or tissue injury, endothelial barrier dysfunction occurs as a consequence as well as cause of inflammatory responses. Plasma leakage disturbs fluid homeostasis and impairs tissue oxygenation, a pathophysiological process contributing to multiple organ dysfunction associated with trauma, infection, metabolic disorder, and other forms of disease. In this book, we provide an updated overview of microvascular endothelial barrier structure and function in health and disease. The discussion is initiated with the basic physiological principles of fluid and solute transport across microvascular endothelium, followed by detailed information on endothelial cell–cell and cell–matrix interactions and the experimental techniques that are employed to measure endothelial permeability. Further discussion focuses on the signaling and molecular mechanisms of endothelial barrier responses to various stimulations or drugs, as well as their relevance to several common clinical conditions. Taken together, this book provides a comprehensive analysis of microvascular endothelial cell and molecular pathophysiology. Such information will assist scientists and clinicians in advanced basic and clinical research for improved health care.
Download or read book Skeletal Muscle Circulation written by Ronald J. Korthuis and published by Morgan & Claypool Publishers. This book was released on 2011 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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
Download or read book Dynamic Aspects of Dental Pulp written by Reizo Inoki and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 503 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a circumspective overview and update of the present existing knowledge of the biology, chemistry and pathophysiology of the dental pulp. It details numerous observations of a group of highly specialized investigators who have united in the common purpose of presenting their observations for the benefit of clinicians, teachers, researchers and students. Fortunately, the dental literature presents abundant research findings about pulp biology and the pulp's responses to various stimuli. This abundance has resulted in an increased interest and expansion of research on this subject. For example, publications abound on the response of pulp tissue to various medications and to a variety of types of dental materials which may be placed near to or at some distance from the pulp through the medium of dentine. One of the reasons the pulp is of such interest is that it not only provides the vitality to the teeth but also produces the dentine - both the primary and secondary, as well as reparative. The latter-type dentine is a result of the pulp's functions in response to disease as the former dentine is in response to health. As an example, some investigators have reported the effects of cutting of dentine and the placement of restorations in dentine which in turn reflect changes on the pulp tissue. These reports have raised a number of questions, which in turn have created a need for answers.
Download or read book Coronary Microvascular Dysfunction written by Filippo Crea and published by Springer Science & Business Media. This book was released on 2013-08-15 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the past two decades a number of studies have shown that abnormalities in the function and structure of coronary microcirculation can be detected in several cardiovascular diseases. On the basis of the clinical setting in which it occurs, coronary microvascular dysfunction (CMD) can be classified into four types: CMD in the absence of any other cardiac disease; CMD in myocardial diseases; CMD in obstructive epicardial coronary artery disease; and iatrogenic CMD. In some instances CMD represents an epiphenomenon, whereas in others it represents an important marker of risk or may contribute to the pathogenesis of myocardial ischemia, thus becoming a possible therapeutic target. This book provides an update on coronary physiology and a systematic assessment of microvascular abnormalities in cardiovascular diseases, in the hope that it will assist clinicians in prevention, detection and management of CMD in their everyday activity.
Download or read book Encyclopedia of Cardiovascular Research and Medicine written by and published by Elsevier. This book was released on 2017-11-27 with total page 2854 pages. Available in PDF, EPUB and Kindle. Book excerpt: Encyclopedia of Cardiovascular Research and Medicine, Four Volume Set offers researchers over 200 articles covering every aspect of cardiovascular research and medicine, including fully annotated figures, abundant color illustrations and links to supplementary datasets and references. With contributions from top experts in the field, this book is the most reputable and easily searchable resource of cardiovascular-focused basic and translational content for students, researchers, clinicians and teaching faculty across the biomedical and medical sciences. The panel of authors chosen from an international board of leading scholars renders the text trustworthy, contemporary and representative of the global scientific expertise in these domains. The book's thematic structuring of sections and in-depth breakdown of topics encourages user-friendly, easily searchable chapters. Cross-references to related articles and links to further reading and references will further guide readers to a full understanding of the topics under discussion. Readers will find an unparalleled, one-stop resource exploring all major aspects of cardiovascular research and medicine. Presents comprehensive coverage of every aspect of cardiovascular medicine and research Offers readers a broad, interdisciplinary overview of the concepts in cardiovascular research and medicine with applications across biomedical research Includes reputable, foundational content on genetics, cancer, immunology, cell biology and molecular biology Provides a multi-media enriched color-illustrated text with high quality images, graphs and tables.
Download or read book Microcirculation written by Ronald F. Tuma and published by Academic Press. This book was released on 2011-04-28 with total page 999 pages. Available in PDF, EPUB and Kindle. Book excerpt: This reference is a volume in the Handbook of Physiology, co-published with The American Physiological Society. Growth in knowledge about the microcirculation has been explosive with the field becoming fragmented into numerous subdisciplines and subspecialties. This volume pulls all of the critical information into one volume. - Meticulously edited and reviewed. Benefit: Provides investigators a unique tool to explore the significance of their findings in the context of other aspects of the microcirculation. In this way, the updated edition has a direct role in helping to develop new pathways of research and scholarship - Highlights the explosive growth in knowledge about the microcirculation including the biology of nitric oxide synthase (NOS), endothelial cell signaling, angiogenesis, cell adhesion molecules, lymphocyte trafficking, ion channels and receptors, and propagated vasomotor responses. Benefit: Microcirculatory biology has become fragmented into numerous sub-disciplines and subspecialties, and these reference reintegrates the information in one volume
Download or read book Inflammation and the Microcirculation written by D. Neil Granger and published by Morgan & Claypool Publishers. This book was released on 2010 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt: The microcirculation is highly responsive to, and a vital participant in, the inflammatory response. All segments of the microvasculature (arterioles, capillaries, and venules) exhibit characteristic phenotypic changes during inflammation that appear to be directed toward enhancing the delivery of inflammatory cells to the injured/infected tissue, isolating the region from healthy tissue and the systemic circulation, and setting the stage for tissue repair and regeneration. The best characterized responses of the microcirculation to inflammation include impaired vasomotor function, reduced capillary perfusion, adhesion of leukocytes and platelets, activation of the coagulation cascade, and enhanced thrombosis, increased vascular permeability, and an increase in the rate of proliferation of blood and lymphatic vessels. A variety of cells that normally circulate in blood (leukocytes, platelets) or reside within the vessel wall (endothelial cells, pericytes) or in the perivascular space (mast cells, macrophages) are activated in response to inflammation. The activation products and chemical mediators released from these cells act through different well-characterized signaling pathways to induce the phenotypic changes in microvessel function that accompany inflammation. Drugs that target a specific microvascular response to inflammation, such as leukocyte-endothelial cell adhesion or angiogenesis, have shown promise in both the preclinical and clinical studies of inflammatory disease. Future research efforts in this area will likely identify new avenues for therapeutic intervention in inflammation. Table of Contents: Introduction / Historical Perspectives / Anatomical Considerations / Impaired Vasomotor Responses / Capillary Perfusion / Angiogenesis / Leukocyte-Endothelial Cell Adhesion / Platelet-Vessel Wall Interactions / Coagulation and Thrombosis / Endothelial Barrier Dysfunction / Epilogue / References
Download or read book Theoretical Models for Blood Flow Regulation in Heterogeneous Microvascular Networks written by Brendan Fry and published by . This book was released on 2013 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proper distribution of blood flow in the microcirculation is necessary to match changing oxygen demands in various tissues. How this coordination of perfusion and consumption occurs in heterogeneous microvascular networks remains incompletely understood. Theoretical models are powerful tools that can help bridge this knowledge gap by simulating a range of conditions difficult to obtain experimentally. Here, an algorithm is first developed to estimate blood flow rates in large microvascular networks. Then, a theoretical model is presented for metabolic blood flow regulation in a realistic heterogeneous network structure, derived from experimental results from hamster cremaster muscle in control and dilated states. The model is based on modulation of arteriolar diameters according to the length-tension characteristics of vascular smooth muscle. Responses of smooth muscle cell tone to myogenic, shear-dependent, and metabolic stimuli are included. Blood flow is simulated including unequal hematocrit partition at diverging vessel bifurcations. Convective and diffusive oxygen transport in the network is simulated, and oxygen-dependent metabolic signals are assumed to be conducted upstream from distal vessels to arterioles. Simulations are carried out over a range of tissue oxygen demand. With increasing demand, arterioles dilate, blood flow increases, and the numbers of flowing arterioles and capillaries, as defined by red-blood-cell flux above a small threshold value, increase. Unequal hematocrit partition at diverging bifurcations contributes to capillary recruitment and enhances tissue oxygenation. The results imply that microvessel recruitment can occur as a consequence of local control of arteriolar tone. The effectiveness of red-blood-cell-dependent and independent mechanisms for the metabolic response of local blood flow regulation is examined over a range of tissue oxygen demands. Model results suggest that although a red-blood-cell-independent mechanism is most effective in increasing flow and preventing hypoxia, the addition of a red-blood-cell-dependent mechanism leads to a higher median tissue oxygen level, indicating distinct roles for the two mechanisms. In summary, flow rates in large microvessel networks can be estimated with the proposed algorithm, and the theoretical model for flow regulation predicts a mechanism for capillary recruitment, as well as roles for red-blood-cell-dependent and independent mechanisms in the metabolic regulation of blood flow in heterogeneous microvascular networks.
Download or read book Coronary Microvascular Obstruction in Acute Myocardial Infarction written by Giampaolo Niccoli and published by Academic Press. This book was released on 2018-07-07 with total page 401 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coronary Microvascular Obstruction in Acute Myocardial Infarction: From Mechanisms to Treatment provides a comprehensive understanding of the phenomenon of coronary microvascular obstruction (CMVO) that is the main limitation of reperfusion therapies in ST-elevation myocardial infarction. It provides in-depth coverage of the phenomenon of CMVO which heavily affects prognosis by increasing the risk of death and heart failure at follow-up. A first of its kind reference dedicated solely to this topic, it is appropriate for a wide audience, from researchers, to those who aid in the management, prevention and treatment of CMVO. Provides in-depth coverage of coronary microvascular obstruction (CMVO), spanning research, management, prevention and treatment Includes the most up-to-date information on CMVO as presented from top experts around the word Provides access to a companion website with extra material, including tables, additional references and instructional videos Gives extensive coverage on how to measure CMVO, including in-depth indexes that can be used to detect and quantify the phenomenon
Download or read book ABC of Hypertension written by D. Gareth Beevers and published by John Wiley & Sons. This book was released on 2010-07-15 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hypertension is a condition which affects millions of peopleworldwide and its treatment greatly reduces the risk of strokes andheart attacks. This fully revised and updated edition of the ABCof Hypertension is an established guide providing all thenon-specialist needs to know about the measurement of bloodpressure and the investigation and management of hypertensivepatients. This new edition provides comprehensively updated andrevised information on how and whom to treat. The ABC of Hypertension will prove invaluable to generalpractitioners who may be screening large numbers of patients forhypertension, as well as nurse practitioners, midwives and otherhealthcare professionals.
Download or read book Cardiovascular Physiology written by Arisztid G. B. Kovách and published by . This book was released on 1981 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Endothelium written by Michel Félétou and published by Morgan & Claypool Publishers. This book was released on 2011 with total page 309 pages. Available in PDF, EPUB and Kindle. Book excerpt: The endothelium, a monolayer of endothelial cells, constitutes the inner cellular lining of the blood vessels (arteries, veins and capillaries) and the lymphatic system, and therefore is in direct contact with the blood/lymph and the circulating cells. The endothelium is a major player in the control of blood fluidity, platelet aggregation and vascular tone, a major actor in the regulation of immunology, inflammation and angiogenesis, and an important metabolizing and an endocrine organ. Endothelial cells controls vascular tone, and thereby blood flow, by synthesizing and releasing relaxing and contracting factors such as nitric oxide, metabolites of arachidonic acid via the cyclooxygenases, lipoxygenases and cytochrome P450 pathways, various peptides (endothelin, urotensin, CNP, adrenomedullin, etc.), adenosine, purines, reactive oxygen species and so on. Additionally, endothelial ectoenzymes are required steps in the generation of vasoactive hormones such as angiotensin II. An endothelial dysfunction linked to an imbalance in the synthesis and/or the release of these various endothelial factors may explain the initiation of cardiovascular pathologies (from hypertension to atherosclerosis) or their development and perpetuation. Table of Contents: Introduction / Multiple Functions of the Endothelial Cells / Calcium Signaling in Vascular Cells and Cell-to-Cell Communications / Endothelium-Dependent Regulation of Vascular Tone / Conclusion / References
