Download or read book The Exocrine Pancreas written by Stephen Pandol and published by Morgan & Claypool Publishers. This book was released on 2011 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: The secretions of the exocrine pancreas provide for digestion of a meal into components that are then available for processing and absorption by the intestinal epithelium. Without the exocrine pancreas, malabsorption and malnutrition result. This chapter describes the cellular participants responsible for the secretion of digestive enzymes and fluid that in combination provide a pancreatic secretion that accomplishes the digestive functions of the gland. Key cellular participants, the acinar cell and the duct cell, are responsible for digestive enzyme and fluid secretion, respectively, of the exocrine pancreas. This chapter describes the neurohumoral pathways that mediate the pancreatic response to a meal as well as details of the cellular mechanisms that are necessary for the organ responses, including protein synthesis and transport and ion transports, and the regulation of these responses by intracellular signaling systems. Examples of pancreatic diseases resulting from dysfunction in cellular mechanisms provide emphasis of the importance of the normal physiologic mechanisms.

Download or read book The Biliary System written by David Q.-H. Wang and published by Morgan & Claypool Publishers. This book was released on 2012 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: The exponential expansion of knowledge in the field of hepatobiliary diseases makes systematic revisions of current concepts almost mandatory nowadays. This eBook summarizes the progress in understanding the molecular mechanism of cholesterol and bile acid metabolism and the physical-chemistry of biliary lipids, with emphasis on biliary lipid metabolism that is regulated by nuclear receptors in the hepatobiliary system. By guiding the readers through the various aspects of anatomy, physiology, and biochemistry of all "players" involved in bile formation, this eBook is intended to be a compendium of recent progresses in understanding the molecular mechanisms of cholesterol and bile acid metabolism. Table of Contents: Introduction / Anatomy of the Liver, Biliary Tract, and Gallbladder / Physical Chemistry of Bile / Hepatic Cholesterol Metabolism / Physical Chemistry and Hepatic Metabolism of Bile Acids / The Enterohepatic Circulation of Bile Acids / Hepatic Secretion of Biliary Lipids and Bile Formation / Summary / Acknowledgments / References / Author Biographies

Download or read book The Endocannabinoid System in Local and Systemic Inflammation written by Melanie E. M. Kelly and published by Biota Publishing. This book was released on 2017-03-29 with total page 209 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the role of the endocannabinoid system in local and systemic inflammation, with individual chapters written by experts in the field of cannabinoid research and medicine. The topics explore the actions of the endocannabinoid system on the immune system, including neuroinflammation in autoimmune disorders such as multiple sclerosis, and in neurodegenerative disorders such as Huntington's and Alzheimer's, as well as local and systemic inflammatory conditions affecting organs including the eye (uveitis and corneal inflammation), the bladder (interstitial cystitis), pancreas (diabetes), cardiovascular system (stroke), joints (arthritis), and sepsis. The objective of this book is to provide knowledge transfer on the use of cannabinoids in inflammatory disease by critically examining preclinical and clinical research on the immunomodulatory actions of the endocannabinoid system, with specific emphasis on the actions of cannabinoids in diseases where inflammation is a prominent component. By drawing these results together, we seek to provide further understanding of the complexities of endocannabinoid system modulation of immune function and identify potential uses and limitations for cannabinoid-based therapeutics.

Download or read book The Renin Angiotensin System and the Kidney written by Xiao C. Li and published by Biota Publishing. This book was released on 2015-03-01 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: The renin-angiotensin system (RAS) is one of the most important endocrine (tissue-to-tissue), paracrine (cell-to-cell) and intracrine (intracellular/nuclear) humoral systems in the regulation of blood pressure, cardiovascular, and kidney function in health and disease. The RAS has remarkably evolved from the initial discovery of the rate-limiting enzyme renin to a complex biochemical and physiological cascade involving more than a dozen members. Currently, there are up to five axes or pathways identified in the RAS; each has its substrate, enzyme, effector peptide, receptor, and downstream signaling pathways. These include the renin/ACE/ANG II/AT1 receptor, the APA/ANG III/AT2 receptor, the ACE2/ANG (1-7)/Mas receptor, the prorenin/prorenin receptor (PRR), and the ANG IV/AT4 receptor (IRAP) pathways. Accordingly, the roles of the RAS have expanded well beyond the classic endocrine paradigm as a powerful vasoconstrictor, a potent aldosterone stimulator, or a sodium-retaining hormonal system. The goals of this article are to review and discuss the current insights into and new perspectives on the expression, localization, and novel actions of the RAS with a focus in the kidney. Special emphasis will be placed on recently discovered new members of the RAS derived from studies using innovative mutant rats or mice that either overexpress (knockin) or are deficient (knockout) of a particular substrate, enzyme, ANG peptide, or receptor. This new knowledge will help improve our understanding how each of these pathways act directly or indirectly to regulate blood pressure, cardiovascular and kidney function in physiology, and can be targeted to treat hypertension, cardiovascular and renal diseases.

Download or read book Hepatic Circulation written by W. Wayne Lautt and published by Biota Publishing. This book was released on 2009-11-01 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Hepatic circulation is unique among vascular beds. The most obvious unique features include the dual vascular supply; the mechanism of intrinsic regulation of the hepatic artery (the hepatic arterial buffer response); the fact that portal blood flow, supplying two thirds of liver blood flow, is not controlled directly by the liver; the fact that 20% of the cardiac output rushes through the most vascularized organ in the body, driven by a pressure gradient of only a few millimeters of mercury; the extremely distensible capacitance and venous resistance sites; the unidirectional acinar blood flow that regulates parenchymal cell metabolic specialization; and the high concentration of macrophagic (Kupffer) cells filtering the blood. The liver is the only organ reported to have regional blood flow monitored by the autonomic nervous system. This mechanism, when dysfunctional, accounts for the hepatorenal syndrome and offers a mechanistic therapeutic target to treat this syndrome. The trigger for liver regeneration is dependent on hepatic hemodynamics so that chronic liver blood flow regulates liver cell mass. In severe liver disease, the whole body circulation is reorganized, by forming portacaval shunts, to accommodate the increased intrahepatic venous resistance. These shunts protect the venous drainage of the splanchnic organs but lead to loss of major regulatory roles of the liver. The development of knowledge of the hepatic vasculature is presented from a historical perspective with modern concepts summarized based on the perspective of the author’s four decades of devotion to this most marvelous of organs.

Download or read book How the Heart Develops written by Donald Fischman and published by Biota Publishing. This book was released on 2009-06-01 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: With possible exception of the atomic clock, the heart may be the most perfect machine ever devised. How it develops from a simple embryonic tube is a fascinating story of biology and lends a great deal of insight into the source of heart defects that affect children and adults alike. Central to this entire lecture is the fact that the fetus resides in an aquatic environment. Oxygenated blood arrives from the placenta and deoxygenated returns to the placenta. The lungs play no role in delivering oxygen or removing carbon dioxide to or from the circulation. Thus, the fetus mainly (but not exclusively) requires a three-chambered heart rather than the fourchambered heart that we are all familiar with. This resembles fish circulation in which blood leaves the heart into an aortic sac from which emanate the aortic arches that deliver blood to the gills, where it is oxygenated and CO2 is removed. Blood then goes to the dorsal aortae for nourishing the body tissues. In a fish there is no need for a four-chambered heart, since fish do not use lungs to aerate the blood or remove CO2. Although the fetus lacks gills and still develops a four-chambered heart, much of fetal circulatory physiology depends on a "quasi-three-chambered circulation" that bypasses the pulmonary circulation. Upon birth, this "aquatic" circulation must change within minutes to permit lung function. The topics to follow trace how this circulation develops and how it changes upon birth. Table of Contents: Fetal and Embryonic Hematopoiesis / Formation of the Precardiac Mesoderm and Fate Mapping During Gastrulation / Tubular Heart / Cardiac Looping / Pericardial Cavity / Endocardial Cushions / Atrial Septation / Ventricular Septation / Partitioning of the Bulbus Cordis and Truncus Arteriosus / Conducting System / Cell Lineages During Heart Development / Circulation at Term and Changes upon Birth / Recommended Readings

Download or read book Inflammation and the Microcirculation written by D. Neil Granger and published by Biota Publishing. This book was released on 2010-06-01 with total page 100 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.

Download or read book The Enteric Microbiota written by Francisco Guarner and published by Morgan & Claypool Publishers. This book was released on 2011-12-13 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: The human gut is the natural habitat for a diverse and dynamic microbial ecosystem having an important impact on health and disease. Bacteria have lived in and on animal hosts since multicellular life evolved about 1 billion years ago. Hosts provide habitat and nutrition to the microbial communities and derive many benefits from their guests that contribute with metabolic (recovery of energy and nutrients), defensive (barrier effect against invaders) and trophic (immune regulation, neuro-endocrine development) functions. Several disease states or disorders have been associated with changes in the composition or function of the enteric microbiota, including inflammatory bowel diseases, obesity and the metabolic syndrome. Probiotics and prebiotics can be used to improve symbiosis between enteric microbiota and host, or correct states of dysbiosis. Table of Contents: Microbial Communities / Host-Microbe Interactions in the Gut / Composition of the Human Enteric Microbiota / Acquisition of the Enteric Microbiota / Dysfunction of the Enteric Microbiota / Therapeutic Manipulation of the Enteric Microbiota / References / Author Biography

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 Endothelin in the Kidney written by David M. Pollock and published by Morgan & Claypool Publishers. This book was released on 2011 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: The discovery of a potent vasoconstrictor, endothelin (ET)-1, derived from vascular endothelial cells was among a variety of key lines of investigation that helped to fuel a major explosion of studies related to endothelial cell biology. This was particularly evident within the pharmaceutical industry where receptor antagonists were quickly developed and are now on the market for treatment of pulmonary hypertension and in development for other diseases such as diabetic nephropathy and cancer. Importantly, we know that the kidney contains the highest level of ET-1 production and receptor expression in the body where it has been demonstrated to function as a pro-natriuretic autocrine and paracrine factor that is activated in conditions of high salt intake. This eBook provides a review of the various mechanisms whereby ET-1 has been shown to function within the kidney through a wide range of actions that include direct effects on tubular transport, intrarenal hemodynamics, as well as neural and endocrine functions. Much has yet to be discerned, but it is clear that the ET system is a major physiological regulator of fluid-electrolyte balance and blood pressure through these renal actions. Table of Contents: Discovery of Endothelin / Basic Biology of the Endothelin System / Renal Localization / Renal Hemodynamics / Renal Tubular Actions of Endothelin / Endothelin in Neural Modulation of Renal Function / Physiological Role of Endothelin / Endothelin in Renal Pathology / References / Author Biographies

Download or read book Cardiovascular Responses to Exercise written by Lusha Xiang and published by Morgan & Claypool Publishers. This book was released on 2012 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exercise is the act of increasing metabolic rate for the purpose of enhancing physical fitness. Exercise can be one of the most stressful physiological responses that the body undertakes. With exercise, there are increases in metabolic rate, heart rate, blood flow (hyperemia), respiration, and heat production. The increased metabolic requirement during exercise is well met by an increased blood flow (functional hyperemia) and oxygen supply to the exercising tissue, which is regulated by multiple local and systemic mechanisms. The local mechanisms (factors) are responsible for mediating the muscle homeostasis and vascular conductance to match the increased metabolic requirement, whereas the systemic mechanisms are responsible for the maintenance of blood pressure and global cardiovascular homeostasis, including the increase in and redistribution of cardiac output, which is mainly mediated by sympathetic activation. For instance, the substantial decreases in vascular resistance and resultant large increase in blood flow during exercise require higher blood pressure and more cardiac output, such that the metabolically active muscle can be perfused with adequate blood flow. This book will provide an overview of the cardiovascular responses to exercise under physiological conditions as well as some pathological circumstances. Table of Contents: Capillary Perfusion in Skeletal Muscle During Exercise / Local Control of Arteriolar Diameter and Blood Flow During Exercise / Systemic Control of Cardiovascular Response to Exercise / Cardiovascular Response to Exercise under Pathological Conditions / References / Author Biography

Download or read book The Lymphatic System in Health and Disease written by J. Winny Yun and published by Biota Publishing. This book was released on 2018-11-09 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: The lymphatic system develops and functions in parallel with the blood circulatory system (termed the "hemovasculature") and accomplishes transport of interstitial fluids, dietary lipids, and reverse transport of cholesterol, immune cells, and antigens—providing a critical homeostatic fluid balance and transmission of immune cells and mediators back to the cardiovascular system. Although the daily flow of lymph (normally 1-2 L/day under unstressed conditions) is far lower than that of daily blood flow (which is 7,500 L/day), without the adequate functioning of the lymphatics, virtually all organs and tissues would acutely suffer many different physical and inflammatory stresses ranging from edema to organ system failure. Although blood and lymphatic vessels often form in anatomic parallels to one another, our knowledge of the workings of the lymphatic system, the fine structure of lymphatic networks, how they function in different organs, and how they are regulated physiologically and immunologically are far from parallel; our knowledge of the lymphatic system still remains at only a tiny fraction of what is understood about the cardiovascular system. Although both the cardiovascular and lymphatic systems are important transport systems, what they transport and how they transport and propel these very different cargoes could not be more dissimilar. This book provides an overview of the history of the discovery (and re-discovery) of the components of the lymphatic system, lymphatic anatomy, physiological functions of lymphatics, molecular features of the lymphatic system, and clinical perspectives involving lymphatics which may be of interest to scientists, clinicians, patients, and the lay public. We provide a current understanding of some of the more important structural similarities and differences between lymphatics and the blood vascular system, their coordinated control by angiogenic and hemangiogenic growth factors and other modulators, the fate and lineage determinants which control lymphatic development, and the roles that lymphatics may play in several different diseases.

Download or read book Necrotizing Enterocolitis written by Michael S. Caplan and published by Biota Publishing. This book was released on 2013-12-01 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: Necrotizing enterocolitis is an acute inflammatory necrosis of bowel that primarily afflicts premature infants in the neonatal intensive care unit setting. Although patients who develop this disease have high morbidity and mortality rates, the pathogenesis is poorly understood, and therefore there are no specific preventive or treatment strategies that have been clearly effective. Recent studies have suggested that the pathophysiology of necrotizing enterocolitis includes alterations in the inflammatory response leading to dysregulated pro-inflammatory signaling in premature infants, as well as abnormal intestinal bacterial colonization patterns that can activate these inflammatory pathways, and these factors are discussed in depth in the following chapters. While human milk feedings are currently the standard of care for the prevention of this challenging condition, new approaches will be described based on sound evidence that might have a significant impact for premature infants throughout the world.

Download or read book Dengue written by Rafael Elias Marques and published by Biota Publishing. This book was released on 2014-02-01 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dengue is a major public health concern throughout the tropical and sub-tropical regions of the world. It is the most rapidly spreading mosquito-borne viral disease, with a 30-fold increase in global incidence over the past 50 years. Infection with any of the Dengue virus serotypes can be asymptomatic, cause the classic dengue fever, or evolve to severe disease, which leads to hypovolemic shock and death if untreated. There is no approved specific treatment, prognostic markers, or vaccines for dengue, in part because there is insufficient knowledge of dengue pathogenesis. In this e-book, we will focus on what we believe to be a true challenge in dengue research: to understand host–pathogen interactions. Disease development results from the interaction between host and viral factors, in which the host immune response is critical. Recent advances in dengue experimental models together with clinical data have provided useful information indicating that severe dengue hallmarks (excessive production of pro-inflammatory cytokines, endothelial activation, and plasma leakage) are immune-mediated events. We hope to present readers with a comprehensive description of the immune response to the Dengue virus, detailing how DENV unbalances host homeostasis.

Download or read book Reactive Oxygen Species and the Cardiovascular System written by Augusto C. Montezano and published by Morgan & Claypool Publishers. This book was released on 2012 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reactive oxygen species (ROS) influence various physiological processes including host defense, hormone biosynthesis, and cellular signaling. Increased ROS production (oxidative stress) is implicated in many diseases of the cardiovascular system, including hypertension, atherosclerosis, cardiac failure, stroke, diabetes, and kidney disease. ROS are produced throughout the cardiovascular system, in the kidney and central and peripheral nervous system. A major source for cardiovascular, renal, and neural ROS is a family of non-phagocytic NAD(P)H oxidases, including the prototypic Nox2 homologue-based NAD(P)H oxidase, as well as other NAD(P)H oxidases, such as Nox1 and Nox4. Other possible sources include mitochondrial electron transport enzymes, xanthine oxidase, cyclooxygenase, lipoxygenase, and uncoupled nitric oxide synthase (NOS). NAD(P)H oxidase-derived ROS is important in regulating endothelial function and vascular tone and oxidative stress is implicated in endothelial dysfunction, inflammation, hypertrophy, apoptosis, migration, fibrosis, angiogenesis and rarefaction, important processes involved in vascular remodeling in cardiovascular disease. These findings have evoked considerable interest because of the possibilities that therapies targeted against non-phagocytic NAD(P)H oxidase to decrease ROS generation and/or strategies to increase nitric oxide (NO) availability and antioxidants may be useful in minimizing vascular injury and thereby prevent or regress target organ damage associated with hypertension and other cardiovascular diseases.

Download or read book Gastrointestinal Mucosal Defense System written by Peter R. Kvietys and published by Biota Publishing. This book was released on 2014-11-01 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: The gastrointestinal mucosal defense system serves to minimize mucosal injury by either ingested or endogenously produced noxious substances. The mucosal defense system is stratified into pre-epithelial (alkaline mucus), epithelial (dynamic epithelial lining), and post-epithelial (microcirculation) components. The mucus lining the epithelial surface presents a diffusional barrier to ingested material (e.g., lipids) and also serves as an unstirred layer in which a pH gradient can be established to prevent acid-induced injury. The epithelial lining prevents entrance of any toxic material to the interstitium and, should it be damaged, it is rapidly resealed by migration of adjacent viable epithelial cells to cover the defect. Any acid or other material that has entered the interstitium is washed out by an intense neurogenic hyperemia. In general, the mucosal defense system is quite effective and any adverse gastrointestinal effects associated with the normal course of nutrient assimilation are minimal. However, there are two situations in which the mucosal defense system is known to be ineffective and result in gastric mucosal injury: inadvertent ingestion of H. pylori. or intentional ingestion of NSAIDs. H. pylori can penetrate the mucus layers and cause epithelial injury and inflammation, while at the same time preventing its clearance by the host immune system. NSAIDs weaken the mucus layer and cause epithelial cell injury. Table of Contents: Acknowledgments / Introduction / The Mucus Layer / Epithelial Lining / Gastrointestinal Circulation / Integration of Mucosal Defense / Mucosal Defense System: Physiologic / Mucosal Defense System: H. pylori / Mucosal Defense System: Nonsteroidal Anti-Inflammatory Drugs (NSAIDS) / Overall Summary and Conclusions / References / Author Biographies

Download or read book Respiratory Muscles written by Gary C. Sieck and published by Biota Publishing. This book was released on 2012-05-01 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: Breathing is usually automatic and without conscious effort; yet our breathing is a complex motor function requiring the coordinated activation of a number of respiratory muscles that span from our heads to our abdomen. Some of our respiratory muscles serve to pump air into and out of our lungs (ventilation). These pump muscles act on the thoracic and abdominal walls and are all skeletal muscles. Other respiratory muscles in our bodies control the caliber of the passageway for air to enter our lungs. These airway muscles include skeletal muscles of the head (e.g., tongue and suprahyoid muscles) and neck (infrahyoid, pharyngeal and laryngeal muscles), as well as smooth muscles that line our trachea and bronchi down to the alveoli where gas exchange occurs. This book provides an overview of the anatomy and physiology of our respiratory muscles, including their neural control. This book also includes an overview of the basic structure and function of both skeletal and smooth muscles. The two basic types of respiratory muscles (skeletal and smooth muscle) vary considerably in the organization of their contractile proteins and the underlying mechanisms that lead to force generation and contraction, including their neural control.