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 Regulation of Smooth Muscle Contraction written by Robert S. Moreland and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 547 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sixth Annual Graduate Hospital Research Symposium REGULATION OF SMOOTH MUSCLE PROGRESS IN SOLVING THE PUZZLE Every so often a scientific conference comes at a time when everyone has new and exciting information, when old "dogmas" do not seem to be as well established, and when speakers and participants alike are ready to challenge interpretations of old and new experimental data. This was such a conference. What turns on a smooth muscle cell? The precise answer to this question has eluded scientists for much longer than I have been involved in the field. We know that an increase in cytosolic calcium is necessary and we know that phosphorylation of the 20 kDa myosin light chain is an important step in the process. We do not know if other processes are necessary for the initiation and lor maintenance of a smooth muscle contraction nor do we know if other processes modulate the regulation of contraction. The goal of the symposium on which this volume is based was to explore the most current hypotheses for the answers to these questions. I believe that after reading the chapters included in this volume, you will agree that this goal was achieved. The importance of calcium and calmodulin dependent myosin light chain phosphoryla tion in the regulation of smooth muscle contraction was reinforced by many presentations. However, the status of myosin light chain phosphorylation as a simple calcium dependent switch came under serious suspicion.

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 Anatomy Physiology written by Lindsay Biga and published by . This book was released on 2019-09-26 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A version of the OpenStax text

Download or read book Colonic Motility written by Sushil K. Sarna and published by Biota Publishing. This book was released on 2010-11-01 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three distinct types of contractions perform colonic motility functions. Rhythmic phasic contractions (RPCs) cause slow net distal propulsion with extensive mixing/turning over. Infrequently occurring giant migrating contractions (GMCs) produce mass movements. Tonic contractions aid RPCs in their motor function. The spatiotemporal patterns of these contractions differ markedly. The amplitude and distance of propagation of a GMC are several-fold larger than those of an RPC. The enteric neurons and smooth muscle cells are the core regulators of all three types of contractions. The regulation of contractions by these mechanisms is modifiable by extrinsic factors: CNS, autonomic neurons, hormones, inflammatory mediators, and stress mediators. Only the GMCs produce descending inhibition, which accommodates the large bolus being propelled without increasing muscle tone. The strong compression of the colon wall generates afferent signals that are below nociceptive threshold in healthy subjects. However, these signals become nociceptive; if the amplitudes of GMCs increase, afferent nerves become hypersensitive, or descending inhibition is impaired. The GMCs also provide the force for rapid propulsion of feces and descending inhibition to relax the internal anal sphincter during defecation. The dysregulation of GMCs is a major factor in colonic motility disorders: irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), and diverticular disease (DD). Frequent mass movements by GMCs cause diarrhea in diarrhea predominant IBS, IBD, and DD, while a decrease in the frequency of GMCs causes constipation. The GMCs generate the afferent signals for intermittent short-lived episodes of abdominal cramping in these disorders. Epigenetic dysregulation due to adverse events in early life is one of the major factors in generating the symptoms of IBS in adulthood.

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 Molecular Control Mechanisms in Striated Muscle Contraction written by R.J. Solaro and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 469 pages. Available in PDF, EPUB and Kindle. Book excerpt: Molecular Control Mechanisms in Striated Muscle Contraction addresses the molecular mechanisms by which contraction of heart and skeletal muscles is regulated, as well as the modulation of these mechanisms by important (patho)physiological variables such as ionic composition of the myoplasm and phosphorylations of contractile and regulatory proteins. For the novice, this volume includes chapters that summarize current understanding of excitation-contraction coupling in striated muscles, as well as the compositions and structures myofibrillar thick and thin filaments. For the expert, this volume presents detailed pictures of current understanding of the mechanisms underlying the CA2+ regulation of contraction in heart and skeletal muscles and discusses important directions for future investigation.

Download or read book Biochemistry of Smooth Muscle Contraction written by Michael Barany and published by Elsevier. This book was released on 1996-01-04 with total page 455 pages. Available in PDF, EPUB and Kindle. Book excerpt: This valuable resource provides a systematic account of the biochemistry of smooth muscle contraction. As a comprehensive guide to this rapidly growing area of research, it covers the structure and characteristic properties of contractile and regulatory proteins, with special emphasis on their predicted function in the live muscle. Also included in this book are intermediate filament proteins, and desmin and vimentin, whose function in smooth muscle is unknown; and several enzymes involved in the phosphorylation-dephosphorylation of contractile and other proteins.

Download or read book Muscle Contraction written by Setsurō Ebashi and published by Springer. This book was released on 1980 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Sliding Filament Theory of Muscle Contraction written by David Aitchison Smith and published by Springer. This book was released on 2019-02-05 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the molecular mechanism of muscle contraction started with the discovery that striated muscle is composed of interdigitating filaments which slide against each other. Sliding filaments and the working-stroke mechanism provide the framework for individual myosin motors to act in parallel, generating tension and loaded shortening with an efficient use of chemical energy. Our knowledge of this exquisitely structured molecular machine has exploded in the last four decades, thanks to a bewildering array of techniques for studying intact muscle, muscle fibres, myofibrils and single myosin molecules. After reviewing the mechanical and biochemical background, this monograph shows how old and new experimental discoveries can be modelled, interpreted and incorporated into a coherent mathematical theory of contractility at the molecular level. The theory is applied to steady-state and transient phenomena in muscle fibres, wing-beat oscillations in insect flight muscle, motility assays and single-molecule experiments with optical trapping. Such a synthesis addresses major issues, most notably whether a single myosin motor is driven by a working stroke or a ratchet mechanism, how the working stroke is coupled to phosphate release, and whether one cycle of attachment is driven by the hydrolysis of one molecule of ATP. Ways in which the theory can be extended are explored in appendices. A separate theory is required for the cooperative regulation of muscle by calcium via tropomyosin and troponin on actin filaments. The book reviews the evolution of models for actin-based regulation, culminating in a model motivated by cryo-EM studies where tropomyosin protomers are linked to form a continuous flexible chain. It also explores muscle behaviour as a function of calcium level, including emergent phenomena such as spontaneous oscillatory contractions and direct myosin regulation by its regulatory light chains. Contraction models can be extended to all levels of calcium-activation by embedding them in a cooperative theory of thin-filament regulation, and a method for achieving this grand synthesis is proposed. Dr. David Aitchison Smith is a theoretical physicist with thirty years of research experience in modelling muscle contractility, in collaboration with experimental groups in different laboratories.

Download or read book Muscle Contraction written by Clive R. Bagshaw and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt: The student of biolo,gical science in his final years as an undergraduate and his first years as a graduate is expected to gain some familiarity with current research at the frontiers of his discipline. New research work is published in a perplexing diversity of publications and is inevitably concerned with the minutiae of the subject. The sheer number of research journals and papers also causes confusion and difficulties of assimilation. Review articles usually presuppose a background knowledge of the field and are inevitably rather restricted in scope. There is thus a need for short but authoritative introductions to those areas of modern biological research which are either not dealt with in standard introductory textbooks or are not dealt with in sufficient detail to enable the student to go on from them to read scholarly reviews with profit. This series of books is designed to satisfy this need. The authors have been asked to produce a brief outline of their subject assuming that their readers will have read and remembered much of a standard introductory textbook of biology. This outline then sets out to provide by building on this basis, the conceptual framework within which modern research work is progressing and aims to give the reader an indication of the problems, both conceptual and practical, which must be overcome if progress is to be maintained.

Download or read book Molecular Biology of The Cell written by Bruce Alberts and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Regulation of Muscle Contraction written by Alan Grinnell and published by . This book was released on 1981 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Structural Basis of Muscular Contraction written by John Squire and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt: Muscular contraction provides one of the most fascinating topics for a biophysicist to study. Although muscle comprises a molecular machine whereby chemical energy is converted to mechanical work, its action in producing force is something that is readily observable in everyday life, a feature that does not apply to most other structures of biophysical inter est. In addition, muscle is so beautifully organized at the microscopic level that those important structural probes, electron microscopy (with the associated image analysis methods) and X-ray diffraction, have pro vided a wealth of information about the arrangements of the constituent proteins in a variety of muscle types. But, despite all this, the answer to the question "How does muscle work?" is still uncertain, especially with regard to the molecular events by which force is actually generated, and the question remains one of the major unsolved problems in biology. With this problem in mind, this book has been written to collect together the available evidence on the structures of the muscle fila ments and on their arrangements in different muscle cells, to extract the common structural features of these cells, and thus to attempt to define a possible series of mechanical steps that will describe at molecular resolu tion the process by which force is generated. The book cannot be considered to be an introductory text; in fact, it presents a very detailed account of muscle structure as gleaned mainly from electron microscopy and X-ray diffraction.

Download or read book Mechanism of Muscular Contraction written by Jack A. Rall and published by Springer. This book was released on 2014-10-21 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the evolution of ideas relating to the mechanism of muscular contraction since the discovery of sliding filaments in 1954. An amazing variety of experimental techniques have been employed to investigate the mechanism of muscular contraction and relaxation. Some background of these various techniques is presented in order to gain a fuller appreciation of their strengths and weaknesses. Controversies in the muscle field are discussed along with some missed opportunities and false trails. The pathway to ATP and the high energy phosphate bond will be discussed, as well as the discovery of myosin, contraction coupling and the emergence of cell and molecular biology in the muscle field. Numerous figures from original papers are also included for readers to see the data that led to important conclusions. This book is published on behalf of the American Physiological Society by Springer. Access to APS books published with Springer is free to APS members.

Download or read book Fundamentals of Anaesthesia written by Colin Pinnock and published by Cambridge University Press. This book was released on 2002-12 with total page 990 pages. Available in PDF, EPUB and Kindle. Book excerpt: The second edition of Fundamentals of Anaesthesia builds upon the success of the first edition, and encapsulates the modern practice of anaesthesia in a single volume. Written and edited by a team of expert contributors, it provides a comprehensive but easily readable account of all of the information required by the FRCA Primary examination candidate and has been expanded to include more detail on all topics and to include new topics now covered in the examination. As with the previous edition, presentation of information is clear and concise, with the use of lists, tables, summary boxes and line illustrations where necessary to highlight important information and aid the understanding of complex topics. Great care has been taken to ensure an unrivalled consistency of style and presentation throughout.

Download or read book Tropomyosin written by Peter Gunning and published by Springer Science & Business Media. This book was released on 2009-09-30 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: A recent review of one of my grant applications commented on the ‘rediscovery of tropomyosin’. I was tempted to write back in my rebuttal to the reviewer that I didn’t realise it had been lost. Uncharacteristic maturity prevailed and I resisted the temptation, but I was struck by the underlying observation that research on the str- ture and function of tropomyosin has been somewhat invisible, particularly in terms of the cytoskeleton isoforms. So, how can it be that one of the two major components of the actin filament has been so thoroughly overlooked? I suspect that the answer is disappointingly pedestrian. Whereas the biochemistry of the 1980s revealed the potential of tropomyosin isoforms to diversify the function of actin filaments, the subsequent disenchantment with isoform biology in general in the 1990s inhibited growth of this field. With the development of more sophisticated experimental - proaches we are now seeing a growing realisation of the importance of tropomyosin in regulating actin filaments beyond its pivotal role in muscle contraction. The opportunity to edit this book came at a time when we had written several reviews on different aspects of tropomyosin function and I had just finished the background reading for a comprehensive review of tropomyosin biology. I realised that the field was simply beyond the capacity of any one person to do the field j- tice.