The Cerebral Circulation

The Cerebral Circulation PDF Author: Marilyn J. Cipolla
Publisher: Biota Publishing
ISBN: 1615047239
Category : Medical
Languages : en
Pages : 82

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Book Description
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.

The Cerebral Circulation

The Cerebral Circulation PDF Author: Marilyn J. Cipolla
Publisher: Biota Publishing
ISBN: 1615047239
Category : Medical
Languages : en
Pages : 82

Get Book Here

Book Description
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.

Regulation of Coronary Blood Flow

Regulation of Coronary Blood Flow PDF Author: Michitoshi Inoue
Publisher: Springer Science & Business Media
ISBN: 4431683674
Category : Medical
Languages : en
Pages : 330

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Book Description
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 Gastrointestinal Circulation

The Gastrointestinal Circulation PDF Author: Peter R. Kvietys
Publisher: Morgan & Claypool Publishers
ISBN: 1615041176
Category : Medical
Languages : en
Pages : 127

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Book Description
The microcirculation of the gastrointestinal tract is under the control of both myogenic and metabolic regulatory systems. The myogenic mechanism contributes to basal vascular tone and the regulation of transmural pressure, while the metabolic mechanism is responsible for maintaining an appropriate balance between O2 demand and O2 delivery. In the postprandial state, hydrolytic products of food digestion elicit a hyperemia, which serves to meet the increased O2 demand of nutrient assimilation. Metabolically linked factors (e.g., tissue pO2, adenosine) are primarily responsible for this functional hyperemia. The fenestrated capillaries of the gastrointestinal mucosa are relatively permeable to small hydrolytic products of food digestion (e.g., glucose), yet restrict the transcapillary movement of larger molecules (e.g., albumin). This allows for the absorption of hydrolytic products of food digestion without compromising the oncotic pressure gradient governing transcapillary fluid movement and edema formation. The gastrointestinal microcirculation is also an important component of the mucosal defense system whose function is to prevent (and rapidly repair) inadvertent epithelial injury by potentially noxious constituents of chyme. Two pathological conditions in which the gastrointestinal circulation plays an important role are ischemia/reperfusion and chronic portal hypertension. Ischemia/reperfusion results in mucosal edema and disruption of the epithelium due, in part, to an inflammatory response (e.g., increase in capillary permeability to macromolecules and neutrophil infiltration). Chronic portal hypertension results in an increase in gastrointestinal blood flow due to an imbalance in vasodilator and vasoconstrictor influences on the microcirculation. Table of Contents: Introduction / Anatomy / Regulation of Vascular Tone and Oxygenation / Extrinsic Vasoregulation: Neural and Humoral / Postprandial Hyperemia / Transcapillary Solute Exchange / Transcapillary Fluid Exchange / Interaction of Capillary and Interstitial Forces / Gastrointestinal Circulation and Mucosal Defense / Gastrointestinal Circulation and Mucosal Pathology I: Ischemia/Reperfusion / Gastrointestinal Circulation and Mucosal Pathology II: Chronic Portal Hypertension / Summary and Conclusions / References / Author Biography

Arteriogenesis

Arteriogenesis PDF Author: Wolfgang Schaper
Publisher: Springer Science & Business Media
ISBN: 1402081251
Category : Medical
Languages : en
Pages : 371

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Book Description
Covers the topic of collateral circulation and its structure and function; its molecular mechanisms during the course of critical arterial stenosis; and how it can be stimulated by physical and growth factors. Animal models are covered in this volume as they reproduce the clinical situation in the laboratory. The book also contains mechanistic explanations of vascular growth that are reflected in numerous charts.

Textbook of Catheter-Based Cardiovascular Interventions

Textbook of Catheter-Based Cardiovascular Interventions PDF Author: Peter Lanzer
Publisher: Springer
ISBN: 331955994X
Category : Medical
Languages : en
Pages : 1887

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Book Description
This book is a fully updated and revised second edition of a highly successful text in which a new concept of knowledge mining, based on explication and transfer of interventional knowledge of experts, has been implemented. The dedicated training program that is set out will serve the needs of all interventional operators, whether cardiologists, vascular surgeons, vascular specialists, or radiologists, enabling them to achieve a consistent expert level across the entire broad spectrum of catheter-based interventions. Operator skills – and in particular decision-making and strategic skills – are the most critical factors for the outcome of catheter-based cardiovascular interventions. Currently, such skills are commonly developed by the empirical trial and error method only. The explicit teaching, training, and learning approach adopted in this book permits the rapid transfer of interventional knowledge and enables individual operators to negotiate steep learning curves and acquire complex skills in a highly efficient manner. It will thereby offer invaluable assistance in meeting successfully the challenges of modern cardiovascular care.

Collateral Circulation of the Heart

Collateral Circulation of the Heart PDF Author: Christian Seiler
Publisher: Springer Science & Business Media
ISBN: 1848823428
Category : Medical
Languages : en
Pages : 427

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Book Description
The sober explanation for this book is a call by the Springer-Verlag, London, to edit a publication on ‘The functional relevance of the collateral circulation’ of the heart. Alternatively, it could be ‘sold’ as the result of my intention to reduce entropy of 18 years of scientific work on the topic of the coronary circulation, which was itself meant to diminish the amount of ‘useless’ energy. Such a process of reducing disarray in a system with the aim of grasping it better is related to simplification, which carries the risk of introducing error. This can be exemplified by the historic view of angina pectoris, which used to be simplified as being always fatal, thus obscuring for nearly two centuries the view of a ‘self-healing’ mechanism such as the collateral circulation of the heart. It would be na? ̈ve, to assume the present work to be free of erroneous oversimplification, because the very nature of scientific work is related to generating (simple) hypotheses with their subsequent falsification. In that context and bluntly, my primary interest in the field of the collateral circulation was not initiated with a vision of eradicating the consequences of coronary artery disease (CAD) by promoting the growth of natural bypasses. The time for such sizeable ideas had passed in the 1970s with the start of the work by Wolfgang Schaper.

Manual of Neurosonology

Manual of Neurosonology PDF Author: László Csiba
Publisher: Cambridge University Press
ISBN: 1107659159
Category : Medical
Languages : en
Pages : 333

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Book Description
Neurosonology is non-invasive, portable, and has excellent temporal resolution, making it a valuable and increasingly popular tool for the diagnosis and monitoring of neurological conditions when compared to other imaging techniques. This guide looks beyond the use of neurovascular ultrasound in stroke to encompass a wide range of other neurological diseases and emergencies. It offers a practical approach to the examination of patients, interpretation of ultrasound studies, and the application of neurosonology to the development of management and treatment strategies. Each chapter incorporates a thorough and clear procedural methodology alongside scanning tips for trainees; this step-by-step approach is further enhanced by example images and focused diagnostic questions. Authored and edited by international experts, this practical manual of neurosonology is an invaluable resource for neurologists, neurosurgeons, intensivists, radiologists, and ultrasonographers.

Collateral Circulation

Collateral Circulation PDF Author: Wolfgang Schaper
Publisher: Springer Science & Business Media
ISBN: 146153092X
Category : Medical
Languages : en
Pages : 411

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Book Description
Collateral blood vessels develop by growth of pre or newly formed structures in almost all vascular provinces as a consequence of progressing stenosis of the main artery. These alternative routes of blood supply are potentially able to alter the course of vascular disease. Collateral development is a time consuming process, and arterial stenosis and occlusion often progress faster than growth of the alternative routes. The authors' ultimate goal is to provide a better understanding of collateral growth in order to pave the way for improving the conditions for these potentially selfhealing processes. These were programmed by nature but have not been perfected, probably because defenses against arterial disease had not been put under the pressure of natural selection.

Physiological Assessment of Coronary Stenoses and the Microcirculation

Physiological Assessment of Coronary Stenoses and the Microcirculation PDF Author: Javier Escaned
Publisher: Springer
ISBN: 144715245X
Category : Medical
Languages : en
Pages : 301

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Book Description
Since the introduction of coronary angiography, a key technique in understanding coronary artery disease, a number of paradigms regarding its study and interpretation have taken place. Following an emphasis on improved angiographic and subsequent intracoronary imaging techniques, functional assessment of coronary circulation has demonstrated to have major implications for diagnosis and treatment of coronary artery disease. Fractional flow reserve, a pressure derived index of stenosis severity, constitutes the best example of the current importance of physiological assessment in clinical practice. However, the acceptance of FFR by cardiologists contrasts with important voids in knowledge on the basic principles of coronary physiology and of other available techniques that, as an alternative to FFR, allow a more comprehensive assessment of coronary circulation. This is particularly noticeable in the assessment of microcirculation, an unavoidable compartment of coronary circulation that is frequently affected in acute coronary syndromes of in the presence of cardiovascular risk factors or non-coronary heart disease. A deeper understanding of the relationship between epicardial vessel and microcirculatory involvement has started with the advent of newer imaging techniques like invasive optical coherence tomography, and non-invasive CT and NMR techniques. This book aims to be an indispensable tool for clinicians and researches in the field of coronary artery disease. It provides a balanced, comprehensive review of anatomy, physiology and available techniques, discusses both the diagnosis of epicardial vessel and microcirculatory disease, the impact of different diseases at different levels of coronary circulation, and the best way to address a separate or combined assessment of different levels of coronary circulation. ​

Vascular Biology of the Placenta

Vascular Biology of the Placenta PDF Author: Yuping Wang
Publisher: Biota Publishing
ISBN: 1615047514
Category : Medical
Languages : en
Pages : 126

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Book Description
The placenta is an organ that connects the developing fetus to the uterine wall, thereby allowing nutrient uptake, waste elimination, and gas exchange via the mother's blood supply. Proper vascular development in the placenta is fundamental to ensuring a healthy fetus and successful pregnancy. This book provides an up-to-date summary and synthesis of knowledge regarding placental vascular biology and discusses the relevance of this vascular bed to the functions of the human placenta.