Download or read book Regulation of Cardiac Contractility written by R. John Solaro and published by Biota Publishing. This book was released on 2011-04-01 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contractility describes the relative ability of the heart to eject a stroke volume (SV) at a given prevailing afterload (arterial pressure) and preload (end-diastolic volume; EDV). Various measures of contractility are related to the fraction as the SV/EDV or the ejection fraction, and the dynamics of ejection as determined from maximum pressure rise in the ventricles or arteries or from aortic flow velocities determined by echocardiography. At the cellular level, the ultimate determinant of contractility is the relative tension generation and shortening capability of the molecular motors (myosin cross-bridges) of the sarcomeres as determined by the rates and extent of Ca activation, the turnover kinetics of the cross-bridges, and the relative Ca responsiveness of the sarcomeres. Engagement of the regulatory signaling cascades controlling contractility occurs with occupancy and signal transduction by receptors for neurohumors of the autonomic nervous system as well as growth and stress signaling pathways. Contractility is also determined by the prevailing conditions of pH, temperature, and redox state. Short-term control of contractility is fully expressed during exercise. In long-term responses to stresses on the heart, contractility is modified by cellular remodeling and altered signaling that may compensate for a time but which ultimately may fail, leading to disorders.
Download or read book Control of Cardiac Output written by David Young and published by Biota Publishing. This book was released on 2010-01-01 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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
Download or read book Cardiac Output and Its Regulation written by Arthur C. Guyton and published by . This book was released on 1963 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Simulation and Imaging of the Cardiac System written by S. Sideman and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ultrasound velocity tomography allows measurement of cardiac geometries for various phases in the cardiac cycle. The present tomograph makes reconstruc tions at intervals of 20 ms. Because of a lack of clear (intramural) landmarks (except the roots of the papillairy muscle), it is difficult to pinpoint spatial trajectories of particular points in the heart. Therefore, a second method was developed of injecting radiopaque markers in the heart and following their motion patterns during the cardiac cycle with help of a biplane X-ray equipment. The data obtained with both methods can be implemented in our finite element model of the heart to compute intramural stresses and strains. The results obtained sofar with the extended Darcy equation to account for the interaction of blood rheology and tissue mechanics look promising. Further testing with more sophisticated subjects than mentioned in Figure 9 is required before it will be implemented in our finite element model of the heart. We conclude that analysis of regional cardiac function, including regional myocardial blood flow, requires still a major research effort but the results obtained sofar justify, to our opinion, a continuation in this direction. Acknowledgement The authors acknowledge Dr. C. Borst and coworkers for doing the animal experiments and prof. Van Campen and dr. Grootenboer for their participation is some aspects of this work.
Download or read book Circulatory Physiology written by Arthur C. Guyton and published by W.B. Saunders Company. This book was released on 1973 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fluid Resuscitation written by Institute of Medicine and published by National Academies Press. This book was released on 1999-11-05 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Historically, 20% of all injured combatants die on the battlefield before they can be evacuated to a field hospital. Blood lossâ€"hemorrhageâ€"is the single major cause of death among those killed in action whose lives might otherwise be saved. Fluid resuscitation and the treatment of hypovolemia (the abnormally decreased volume of circulating fluid in the body) offer the greatest opportunity for reducing mortality and morbidity associated with battlefield casualties. In Fluid Resuscitation, a committee of experts assess current resuscitation fluids and protocols for the treatment of combat casualties and make recommendations for future research. Chapters focus on the pathophysiology of acute hemorrhagic shock, experience with and complications of fluid resuscitation, novel approaches to the treatment of shock, protocols of care at the site of injury, and future directions for research. The committee explicitly describes the similarities and differences between acute medical care during combat and civilian emergency trauma care. Fluid Resuscitation should help energize and focus research in both civilian and military emergency care and help save the lives of citizens and soldiers alike.
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 Cardiopulmonary Monitoring written by Sheldon Magder and published by Springer Nature. This book was released on 2021-09-01 with total page 952 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers a comprehensive overview of the basic physiology of the cardiac and pulmonary systems, tools for cardiopulmonary monitoring, and related issues in the management of specific conditions. The volume is divided into three main parts. The first part examines the functional basis of normal and abnormal physiology, organized into cardiac and pulmonary units and followed by a “combined” interactive component. The next section discusses cardiopulmonary monitoring tools and variables and is also divided into cardiac (e.g, echocardiography, heart rate, cardiac output), pulmonary (e.g, lung volume, pleural pressure, electrical impedance tomography), and combined tools such as radiology/MRI and tissue perfusion tests. The third section concerns the management and application of specific clinical problems such as pulmonary hypertension, cardiac shunts, cardiogenic shock, and ECMO with an emphasis on the physiological basics. /div Cardiopulmonary Monitoring: Basic Physiology, Tools, and Bedside Management for the Critically Ill is an essential resource for physicians, residents, fellows, medical students, and researchers in cardiology, critical care, emergency medicine, anesthesiology, and radiology.
Download or read book Cardiovascular Regulation written by David Jordan and published by Ashgate Publishing. This book was released on 1995 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Studies in Physiology series provides a concise introduction to developments in complex areas of physiology for a wide audience. Published on behalf of the Physiology Society, Cardiovascular Regulation provides an up-to-date account of our current understanding of the control of the cardiovascular system that is not covered by existing textbooks. Both students and lecturers of cardiovascular and exercise physiology, medicine, dentistry and biomedical sciences will find this book informative and easy to read. Each chapter has numerous summary boxes. 'Essential reading' suggestions provide additional reading for undergraduates and the suggestions for 'Further reading' cover the subject to postgraduate level.
Download or read book Circulatory Physiology Cardiac Output and Its Regulation 2nd Ed written by Arthur C. Guyton and published by . This book was released on 1973 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Anatomy and Physiology written by J. Gordon Betts and published by . This book was released on 2013-04-25 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Exercise Cardiopulmonary Function in Cardiac Patients written by Michael S. Sagiv and published by Springer Science & Business Media. This book was released on 2012-05-08 with total page 267 pages. Available in PDF, EPUB and Kindle. Book excerpt: The textbook will describe the relationship between human cardiopulmonary system and exercise in a format that is related to the mode of exercise, health status and aging. It will include data regarding exercise training principles and the adaptations of the cardiopulmonary following: anaerobic, resistance and aerobic training. A more in-depth presentation of the cardiopulmonary system adaptations in pressing environments such as: warm, cold and altitude. Therefore, students will experience a depth and extent of content balanced with unique and effective learning features: It will help students find the way by both the text and subject matter. Knowing cardiopulmonary exercise function in health and disease will allow understand new research and findings relevant to cardiovascular status as assessed by cardiopulmonary exercise indices. It will bring together investigational exercise physiologists, cardiologists and scientists who share a wealth of experience needed to judge the cardiovascular status and function, and the impairments of patients with a variety of cardiac dysfunction. This book will provide a comprehensive, updated presentation of the information of the cardiovascular system as a whole, and its individual components.
Download or read book Basic Physiology for Anaesthetists written by David Chambers and published by Cambridge University Press. This book was released on 2019-07-25 with total page 469 pages. Available in PDF, EPUB and Kindle. Book excerpt: Easily understood, up-to-date and clinically relevant, this book provides junior anaesthetists with an essential physiology resource.
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 Oxygen Transport to Tissue XXVII written by Giuseppe Cicco and published by Springer Science & Business Media. This book was released on 2006-11-22 with total page 393 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the proceedings of the 32nd scientific meeting of the International Society on Oxygen Transport to Tissue (ISOTT) in Bari, Italy, August 21-26, 2004. It covers all aspects of oxygen delivery to tissue, including blood flow and its regulation as well as oxygen metabolism. Special emphasis is placed on methods of oxygen measurement in living tissue and application of these technologies to understanding physiological and biochemical basis for pathology related to tissue oxygenation. The event hosted was a multidisciplinary meeting designed to bring together experts and students from a range of research fields.
Download or read book Control of Cardiac Output written by David B. Young and published by Morgan & Claypool Publishers. This book was released on 2010 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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
