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.

ABC of Hypertension

ABC of Hypertension PDF Author: D. Gareth Beevers
Publisher: John Wiley & Sons
ISBN: 1405171359
Category : Medical
Languages : en
Pages : 89

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Book Description
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.

The Endothelium

The Endothelium PDF Author: Michel Félétou
Publisher: Morgan & Claypool Publishers
ISBN: 1615041230
Category : Science
Languages : en
Pages : 309

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Book Description
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

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.

Regulation of Tissue Oxygenation, Second Edition

Regulation of Tissue Oxygenation, Second Edition PDF Author: Roland N. Pittman
Publisher: Biota Publishing
ISBN: 1615047212
Category : Medical
Languages : en
Pages : 117

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Book Description
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.

Endothelium and Cardiovascular Diseases

Endothelium and Cardiovascular Diseases PDF Author: Protasio L. Da Luz
Publisher: Academic Press
ISBN: 0128125519
Category : Medical
Languages : en
Pages : 760

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Book Description
Endothelium and Cardiovascular Diseases: Vascular Biology and Clinical Syndromes provides an in-depth examination of the role of endothelium and endothelial dysfunction in normal vascular function, and in a broad spectrum of clinical syndromes, from atherosclerosis, to cognitive disturbances and eclampsia. The endothelium is a major participant in the pathophysiology of diseases, such as atherosclerosis, diabetes and hypertension, and these entities are responsible for the largest part of cardiovascular mortality and morbidly. Over the last decade major new discoveries and concepts involving the endothelium have come to light. This important reference collects this data in an easy to reference resource. Written by known experts, and covering all aspects of endothelial function in health and disease, this reference represents an assembly of recent knowledge that is essential to both basic investigators and clinicians. - Provides a complete overview of endothelial function in health and diseases, along with an assessment of new information - Includes coverage of groundbreaking areas, including the artificial LDL particle, the development of a new anti-erectile dysfunction agent, a vaccine for atherosclerosis, coronary calcification associated with red wine, and the interplay of endoplasmic reticulum/oxidative stress - Explores the genetic features of endothelium and the interaction between basic knowledge and clinical syndromes

Arterial Vasodilation

Arterial Vasodilation PDF Author: Michael F. O'Rourke
Publisher:
ISBN: 9780812116717
Category : Medical
Languages : en
Pages : 231

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Book Description


Pathophysiology of Heart Disease

Pathophysiology of Heart Disease PDF Author: Naranjan S. Dhalla
Publisher: Springer Science & Business Media
ISBN: 9780898388640
Category : Medical
Languages : en
Pages : 398

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Book Description
It is indeed ironical that in the absence of a complete knowledge of Pathophysiology, clinical cardiologists are left with no choice but to do the best they can to help the patient with the armamentarium of drugs at their disposal. But nothing could be further from truth than to treat the diagnosed end point of a disease process without a full understanding of its patho physiology. This point was eloquently made by Dr. Arnold Katz in his Presidential Address (Chapter 1) at the 8th Annual Meeting of the American Section of the International Society for Heart Research held in Winnipeg, Canada, July 8-11, 1986. This volume represents a part of the scientific proceedings of this Meeting. From a reading of this treatise it will become evident that discoveries of newer scientific facts as well as a better understanding of pathophysiology are continuously influencing/ improving our therapeutic approaches in modern medicine. In this book, latest biochemical, physiological and pharmacological findings on different experimental models such as Myocaridal hypertrophy, Hypertension and heart failure, Diabetes, Cardio myopathies and Cardiac function in shock are described by internationally recognised experts. Hopefully information presented here will provide another building block to the edifice of Science of Cardiology which we all are trying to create. Acknowledgements We are grateful to the following Agencies and Foundations for their generous financial support of the Symposium, which formed the basis of this book. A. Major Contributors: 1. Manitoba Heart Foundation 2. Sterling-Winthrop Research Institute 3. Squibb Canada, Inc.

Skeletal Muscle Circulation

Skeletal Muscle Circulation PDF Author: Ronald J. Korthuis
Publisher: Morgan & Claypool Publishers
ISBN: 1615041834
Category : Medical
Languages : en
Pages : 147

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Book Description
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