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The unique anatomy and physiology of the pleural space provides tight regulation of liquid within the space under normal physiologic conditions. When this balance is disrupted and pleural effusions develop, there can be significant impacts on the respiratory system. Drainage of effusions can lead to meaningful improvement in symptoms, primarily owing to improvement in the length-tension relationship of the respiratory muscles. Ultrasound examination to evaluate the movement and function of the diaphragm, as well as pleural manometry, have provided a greater understanding of the impact of pleural effusion and thoracentesis.

Febrile neutropenia (FN) is a common and dangerous consequence of myelosuppressive chemotherapy but can occur as part of the disease processes. Bacterial bloodstream infection is the most commonly diagnosed cause of febrile neutropenia, with Gram-positive organisms most frequently isolated. However, Gram-negative organisms are becoming more prevalent, with a worrying trend towards resistant organisms. When FN is prolonged, lasting for more than 5 days, there is an increased risk of invasive fungal infections. Prompt recognition, diagnosis and initiation of treatment with broad-spectrum antibiotics are essential to avoid complications and prevent rapid progression to sepsis and possible death. This short article summarises the definition, causes, pathogenesis, applied physiology and management of FN in children.

Different theories have been proposed to explain hypertension from an Ayurvedic perspective, but there is no consensus amongst the experts. A better understanding of the applied physiology and etio-pathogenesis of hypertension in the light of Ayurvedic principles is being attempted to fill this gap. A detailed review of available Ayurvedic literature was carried out to understand the physiology of blood pressure and etio-pathogenesis of hypertension from the perspective of Ayurveda. Many parallels were drawn from the concepts such as Shad Kriyakala (six stages of Dosha imbalance) and Avarana of Doshas (occlusion in the normal functioning of the Doshas) to the modern pathogenesis of hypertension to gain a deeper understanding of it. Hypertension without specific symptoms in its mild and moderate stages cannot be considered as a disease in Ayurveda. It appears to be an early stage of pathogenesis and a risk factor for development of diseases affecting the heart, brain, kidneys and eyes etc. Improper food habits and modern sedentary lifestyle with or without genetic predisposition provokes and vitiates all the Tridoshas to trigger the pathogenesis of hypertension. It is proposed that hypertension is to be understood as the Prasara-Avastha which means spread of vitiated Doshas from their specific sites, specifically of Vyana Vata, Prana Vata, Sadhaka Pitta and Avalambaka Kapha along with Rakta in their disturbed states. The Avarana (occlusion of normal functioning) of Vata Dosha by Pitta and Kapha can be seen in the Rasa-Rakta Dhathus, which in turn hampers the functioning of the respective Srotas (micro-channels) of circulation.

Background. This study aimed to evaluate the physiological strain index (PSI) along with specific immune system markers in response to a simulated firefighting occupation workload. Methods. Ten hea...

Similar to human beings, pain is an unpleasant sensation experienced by animals as well. There is no exception when the animals are subjected to experimental procedures. Our duty as researchers/scientists is to prevent or minimize the pain in animals so as to lessen their suffering and distress during experimental procedures. The basics of the physiology of pain and pain perception, analgesia, anesthesia, and euthanasia of laboratory animals were included to complete the program, before the practical part was attempted and before advanced topics, such as comparison of anesthetic combinations, were discussed. Therefore, this course was organized in Sri Lanka for the first time in collaboration with the Comparative Biology Centre of Newcastle University, UK. During this course, we were able to demonstrate how an anesthesia machine could be used in laboratory animal anesthesia for the first time in the country. None of the animal houses in the country were equipped with an anesthesia machine at the time of conducting the course.

Different theories have been proposed to explain hypertension from an Ayurvedic perspective, but there is no consensus amongst the experts. A better understanding of the applied physiology and etio-pathogenesis of hypertension in the light of Ayurvedic principles is being attempted to fill this gap. A detailed review of available Ayurvedic literature was carried out to understand the physiology of blood pressure and etio-pathogenesis of hypertension from the perspective of Ayurveda. Many parallels were drawn from the concepts such as Shad Kriyakala (six stages of Dosha imbalance) and Avarana of Doshas (occlusion in the normal functioning of the Doshas) to the modern pathogenesis of hypertension to gain a deeper understanding of it. Hypertension without specific symptoms in its mild and moderate stages cannot be considered as a disease in Ayurveda. It appears to be an early stage of pathogenesis and a risk factor for development of diseases affecting the heart, brain, kidneys and eyes etc. Improper food habits and modern sedentary lifestyle with or without genetic predisposition provokes and vitiates all the Tridoshas to trigger the pathogenesis of hypertension. It is proposed that hypertension is to be understood as the Prasara-Avastha which means spread of vitiated Doshas from their specific sites, specifically of Vyana Vata, Prana Vata, Sadhaka Pitta and Avalambaka Kapha along with Rakta in their disturbed states. The Avarana (occlusion of normal functioning) of Vata Dosha by Pitta and Kapha can be seen in the Rasa-Rakta Dhathus, which in turn hampers the functioning of the respective Srotas (micro-channels) of circulation. Keywords: Hypertension, Ayurveda, Blood pressure, Etio-pathogenesis

The quadrennial International Conference on Equine Exercise Physiology (ICEEP) allows focused presentations of a variety of horse exercise- and performance-related research data in cardiorespiratory, muscle, biomechanics, nutrition, genomics, and applied physiology. The most diverse section of the ICEEP meeting has been termed variously ‘Applied Exercise Physiology’ (ICEEP 8 and 9), ‘Applied Physiology: Training Methods, Exercise Testing and Selection’ (ICEEP 7), or ‘Applied Physiology of Athletic Performance’ (ICEEP 6 and earlier). The next ICEEP meeting is scheduled to be held in Australia in 2018. In this subspeciality of equine exercise physiology, scientists attempt to apply or put into practical field use the techniques and tools developed in the more basic sciences in order to assess the performance, training, and injury of horses working and performing under true, non-laboratory conditions. The real test of the value of this subspeciality will be the increased application and sustainability of the use of laboratory techniques in the assessment of equine athletes in field settings. This review summarises exercise physiology findings prior to the widespread use of equine laboratory treadmills which have tethered investigators to the laboratory, and explains and illustrates newer, more portable, often digital technological developments which have allowed investigations to move out of the laboratory and back to the field setting where horses train and compete on a daily basis.

Despite the availability and utilization of the physiology textbooks authored by Albrecht von Haller during the 18th century that heralded the modern age of physiology, not all physicians or physiologists were satisfied with its presentation, contents, or application to medicine. Initial reasons were fundamental disagreements between the “mechanists,” represented by Boerhaave, Robinson, and von Haller, and the “vitalists,” represented by the faculty and graduates of the Montpellier School of Medicine in France, notably, Bordeu and Barthez. Subsequently, objections originated from Europe, United Kingdom, and the United States in publications that focused not only on the teaching of physiology to medical and secondary students, but on the specific applications of the content of physiology to medicine, health, hygiene, pathology, and chronic diseases. At the turn of the 20th century, texts began to appear with applied physiology in their titles and in 1926, physician Samson Wright published a textbook entitled Applied Physiology that was intended for both medical students and the medical profession. Eleven years later, physicians Best and Taylor published The Physiological Basis of Medical Practice: A University of Toronto Texbook in Applied Physiology. Although both sets of authors defined the connection between applied physiology and physiology, they failed to define the areas of physiology that were included within applied physiology. This was accomplished by the American Physiological Society (APS) Publications Committee in 1948 with the publication of the Journal of Appplied Physiology, that stated the word “applied” would broadly denote human physiology whereas the terms stress and environment would broadly include work, exercise, plus industrial, climatic and social factors. NIH established a study section (SS) devoted to applied physiology in 1964 which remained active until 2001 when it became amalgamated into other SSs. Before the end of the 20th century when departments were changing their titles to reflect a stronger science orientation, many established laboratories and offered degree programs devoted to Applied Physiology. We concluded that Applied Physiology has been an important contributor to the discipline of physiology while becoming an integral component of APS.

Transient loss of consciousness (TLOC) is spontaneous loss of consciousness with complete recovery; there is temporary impairment of brain function associated with loss of awareness, loss of responsiveness, and loss of memory. Syncope is the most common cause of transient loss of consciousness in children. Whilst syncope is potentially easy to understand using applied physiology, therapeutic opportunities are often missed, leading to avoidable morbidity and disability. In this article we will discuss the causes of TLOC and focus on the evaluation and management of syncope and orthostatic intolerance in children and young people.

Physiological arousal has been increasingly applied to monitor exploration (or navigation) of a virtual environment (VE), especially when the VE is designed to evoke an anxiety-related response. The present work aims to evaluate human physiological reactions to safe and unsafe VEs. We compared the effect of the presence of handrails in the VE in two different samples, young and older adults, through self-reports and physiological data: Electrodermal activation (EDA) and electrocardiogram (ECG) sensors. After navigation, self-report questionnaires were administered. We found that the VEs evoked a clearly differentiated perception of safety and unsafety demonstrated through self-reports, with older adults being more discriminative in their responses and reporting a higher sense of presence. In terms of physiological data, the effect of handrails did not provoke significant differences in arousal. Safety was better operationalized by discriminating neutral/non-neutral spaces, where the reaction of older adults was more pronounced than young adults. Results serve as a basis for orienting future experiments in the line of VE and applied physiology usage in the architectural spaces design process. This specific work also provided a basis for the development of applications that integrate virtual reality and applied biofeedback, tapping into mobility and ageing. info:eu-repo/semantics/publishedVersion

Surgery has become safer and safer over the last decades on the one hand as a result of highly sophisticated non-invasive approaches that aim to replace operations with excessive tissue trauma and on the other hand due to the developments in anesthesiology and intensive therapy. The latter has been mentioned more and more frequently in the context of perioperative medicine often referred to as an entity on its own. This means that pre-, intra-, and postoperative care should not be considered as independent components managed by different teams but rather dealt with as one process and managed by using a holistic approach.

Large multicenter, randomized controlled trials published in reputable journals had a large impact on the world of cardiothoracic anesthesia in 2015. We as cardiac anesthesiologists pride ourselves as being experts in applied physiology, physics, ultrasonography, and pharmacology/pharmacotherapy. The selected studies added to our knowledge in the fields of echocardiography, pharmacology, molecular biology, and genetics. Outcome studies shine a light on important topics that are relevant to all cardiac anesthesiologists: does surgical atrial fibrillation ablation during mitral valve surgery reduce the recurrence of atrial fibrillation at 1 year after surgery? Does remote ischemic preconditioning live up to its promise to reduce postoperative major cardiac and cerebral events? Although we still do not have the answer to all the questions, the year 2015 has been a great step toward the goal of understanding molecular mechanisms of ischemic myocardial injury and toward providing evidence-based medicine for improving patient outcome.

Equine exercise physiology is a discipline that emerged in the 1980s. It has enjoyed tremendous popularity. Areas of popularity in equine exercise physiology research have changed over the past 40 years for a variety of possible reasons, including funding, disappearance of research groups, and research interests. We are also now in a position where we can review earlier studies in a different, more informed light and consider which ones are still reliable and relevant and which ones may need to be considered differently based on more recent knowledge. Although traditionally popular areas in equine exercise research such as respiratory, cardiovascular, and muscular research have diminished, other areas such as biomechanics and locomotion and applied physiology have seen great growth. Although much has been achieved which has contributed to scientific understanding of the horse in relation to exercise and to welfare, some obvious areas remain poorly understood.

This is a post-peer-review, pre-copyedit version of an article published in European Journal of Applied Physiology. The final authenticated version is available online at: http://dx.doi.org/10.1007/s00421-017-3616-y

The objective of this study is to make a review of the narrative of coronary artery tortuosity (CAT) approaching several situations in clinical practice where tortuosity can have a relevant role, and also evaluate if tortuosity can be related to the presence of myocardial ischemia in patients without coronary obstruction using scientific evidences in medical literature. Textbook of applied Physiology in Cardiology with study of coronary circulation, theoretical articles with studies of Hemodynamics, Fluid and Mechanical Dynamic, and experimental articles with simulation in computers were used as support to answer this last question. Resumo Este trabalho faz uma revisão sobre o tema de tortuosidade coronariana abordando várias situações na prática clínica aonde a tortuosidade coronariana pode desempenhar um papel relevante e procura avaliar se há correlação entre tortuosidade coronariana e a presença de isquemia miocárdica em pacientes sem obstruções coronarianas fazendo uma busca na literatura das evidências científicas. Livro-texto de Fisiologia em Cardiologia com estudo da circulação coronariana, artigos teóricos com estudos de Hemodinâmica, Dinâmica de Fluidos e de Mecânica e artigos experimentais com simulação em computadores serviram de sustentação para a formulação da hipótese a ser verificada.

Breathing affects cardiac output on a cycle-by-cycle basis, through changes in pressure and intrathoracic volume of key components in cardiovascular function Hence, heart–lung interactions affect cardiovascular functioning and the heart's ability to adapt. The heart–lung interaction is an area of applied physiology broadly studied but in Colombia, this is the first trial ever done with a thoracic bioreactance monitor. The hemodynamic profiles of 38 patients scheduled for myocardial revascularization were measured at the Fundacion Clinica Abood Shaio using thoracic bioreactance monitor, which provided ventricular volume and cardiac output measurements. The ventilator volumes and pressures with which corrections were made to interpret the effects of mechanical ventilation were recorded.

While the importance of regulating arterial blood pressure within a 'normal' range is widely appreciated, the definition of 'normal' and the means by which humans and other species regulate blood pressure under various conditions remain hotly debated. The effects of diverse physiological, pathological and environmental challenges on blood pressure and the mechanisms that attempt to maintain it at an optimal level are reviewed and critically analyzed in a series of articles published in this themed issue of the European Journal of Applied Physiology. We summarize here the major points made in these reviews, with emphasis on unifying concepts of regulatory mechanisms and future directions for research.

In Italy the existence of a law on health protection of competitive sports since 1982 has favored the creation and the revision of these cardiological guidelines (called COCIS), which have reached their fourth edition (1989-2009). The present article is the second English version, which has summarized the larger version in Italian. The experience of the experts consulted in the course of these past 20 years has facilitated the application and the compatibility of issues related to clinical cardiology to the sports medicine field. Such prolonged experience has allowed the clinical cardiologist to acquire knowledge of the applied physiology of exercise and, on the other hand, has improved the ability of sports physicians in cardiological diagnostics. All this work has produced these guidelines related to the judgment of eligibility for competitive sports in the individual clinical situations and in the different cardiovascular abnormalities and/or heart disease. Numerous arguments are debated, such as interpretation of the athlete's ECG, the utility of a preparticipation screening, arrhythmias, congenital heart disease, cardiomyopathies, arterial hypertension, ischemic heart disease and other particular issues.

This focused review serves to explore relevant issues in regard to blood pressure regulation and by doing so, provides the initial stimulus paper for the Thematic Review series “Blood Pressure Regulation” to be published in the European Journal of Applied Physiology over the coming months. In this introduction, we highlight how variable normal blood pressure can be and challenge the reader to take another look at some key concepts related to blood pressure regulation. We point out that there is frequently an underappreciated balance between peripheral vasodilation and systemic blood pressure regulation and ask the question: Are changes in blood pressure, in effect, reasonable and integrated adaptations to the physiological challenge at hand? We conclude with the idea that blood pressure regulatory systems are both flexible and redundant; ensuring a wide variety of activities associated with life can be accompanied by a perfusion pressure that can serve multiple masters.

this volume of the Journal of Applied Physiology marks publication of our first CORP article ([1][1]). It is a statistical essay on best practices to minimize the probability of studies coming up with either false positive or false negative conclusions. CORP (Cores of Reproducibility in Physiology)

This paper was accepted for publication in the journal Journal of Applied Physiology and the definitive published version is available at https://doi.org/10.1152/japplphysiol.00089.2018.

The aquatic environment has broad rehabilitative potential, extending from the treatment of acute injuries through health maintenance in the face of chronic diseases, yet it remains an underused modality. There is an extensive research base supporting aquatic therapy, both within the basic science literature and clinical literature. This article describes the many physiologic changes that occur during immersion as applied to a range of common rehabilitative issues and problems. Because of its wide margin of therapeutic safety and clinical adaptability, aquatic therapy is a very useful tool in the rehabilitative toolbox. Through a better understanding of the applied physiology, the practitioner may structure appropriate therapeutic programs for a diverse patient population.

The course “Management of Fluid and Electrolyte Disorders” is an applied physiology course taught using lectures and paper-based cases. The course approaches fluid therapy from both basic science and clinical perspectives. While paper cases provide a basis for application of basic science concepts, they lack key components of genuine clinical cases that, by nature, are diverse, change over time, and respond in unique ways to therapeutic interventions. We developed a dynamic model using STELLA software that simulates normal and abnormal fluid and electrolyte balance in the dog. Students interact, not with the underlying model, but with a user interface that provides sufficient data (skin turgor, chemistry panel, etc.) for the clinical assessment of patients and an opportunity for treatment. Students administer fluids and supplements, and the model responds in “real time,” requiring regular reassessment and, potentially, adaptation of the treatment strategy. The level of success is determined by clinical outcome, including improvement, deterioration, or death. We expected that the simulated cases could be used to teach both the clinical and basic science of fluid therapy. The simulation provides exposure to a realistic clinical environment, and students tend to focus on this aspect of the simulation while, for the most part, ignoring an exploration of the underlying physiological basis for patient responses. We discuss how the instructor's expertise can provide sufficient support, feedback, and scaffolding so that students can extract maximum understanding of the basic science in the context of assessing and treating at the clinical level.

Pelvic floor muscles have two major functions: they provide support or act as a floor for the abdominal viscera including the rectum; and they provide a constrictor or continence mechanism to the urethral, anal, and vaginal orifices (in females). This article discusses the relevance of pelvic floor to the anal opening and closure function, and discusses new findings with regards to the role of these muscles in the vaginal and urethra closure mechanisms.

Early diagnosis has been the 'Achilles heel' of acute kidney injury (AKI) that has prevented successful implementation of treatment strategies. To date, pharmacological intervention has been largely unsuccessful or equivocal, and morbidity and mortality associated with AKI have remained unacceptably high. Despite their well-known limitations, the most widely used biomarkers for the early diagnosis of AKI are serum creatinine, blood urea nitrogen and urine output. Development of new biomarkers is imperative. A variety of methods have been employed to discover new biomarkers of AKI, including transcriptomics, proteomics, gene arrays, lipidomics and imaging technologies. Clinical trials are underway to establish the validity of the biomarkers discovered using these techniques. This Review summarizes the importance of biomarkers of AKI, from their discovery to clinical practice, from the current perspective and that of what to expect in the future. Great strides forward are being made in breaking down important barriers to the successful prevention and treatment of this devastating disorder.

Objective:This commentary discusses known links between Exertional Heat Illness (EHI), Malignant Hyperthermia (MH), and other hereditary diseases of muscle. Genetic and functional testing is also evaluated as measures of fitness to return to duty/play.Data Sources:Reviews and research articles from Sports Medicine, Applied Physiology, and Anesthesiology.Data Extraction:Detailed comparisons of existing literature regarding clinical cases of EHI and MH and the potential utility of genetic testing, specifically the ryanodine receptor (RYR1) gene and other genes related to disorders of skeletal muscle.Data Synthesis:EHI is a complex disorder wherein physiological, environmental, and hereditary factors interact to endanger an individual’s ability to maintain thermal homeostasis.Conclusions:Individuals’ genetic background is likely to play an important role, particularly when EHI recurs. Recurrent EHI has been associated with MH and other genetic disorders, highlighting the importance of identification and exclusion of individuals with known high risk factors.

SUMMARY The treatment of pancreatic steatorrhoea can often be improved by attention to the pathophysiological and pharmacological principles involved. Factors influencing the efficacy of pancreatic enzyme replacement include physiological characteristics of the individual patient and pharmaceutical characteristics of the supplement. Different patients may be best suited by different preparations and there is no overall ‘best buy’. The new enteric-coated microsphere formulations are often most effective, but also more expensive than conventional preparations. Adjunctive H2-blockade can help appropriately selected patients with resistant steatorrhoea. Knowledge of the underlying cause may guide the choice of supplement and its dose, but trials of different regimens may prove necessary. Successful management, particularly of malnourished patients, involves optimization of dietary fat intake in addition to enzyme replacement.

To understand pitfalls and limitations in adult renography, it is necessary to understand firstly the physiology of the kidney, especially the magnitude and control of renal blood flow, glomerular filtration rate and tubular fluid flow rate, and secondly the pharmacokinetics and renal handling of the three most often used tracers, Tc-99m-mercaptoacetyltriglycine (MAG3), Tc-99m-diethylene triamine pentaacetic acid (DTPA) and Tc-99m-dimercaptosuccinic acid (DMSA). The kidneys may be imaged dynamically with Tc-99m-MAG3 or Tc-99m-DTPA, with or without diuretic challenge, or by static imaging with Tc-99m-DMSA. Protocols are different according to whether the kidney is native or transplanted. Quantitative analysis of dynamic data includes measurement of renal vascularity (important for the transplanted kidney), absolute tracer clearance rates, differential renal function (DRF) and response to diuretic challenge. Static image reveals functional renal parenchymal damage, both focal and global, is useful in the clinical management of obstructive uropathy, renal stone disease and hypertension (under angiotensin converting enzyme inhibition), and is the preferred technique for determining DRF. Diagnosis based on morphological appearances is important in transplant management. Even though nuclear medicine is now in the era of hybrid imaging, renal imaging remains an important subspecialty in nuclear medicine and requires a sound basing in applied physiology, the classical supporting discipline of nuclear medicine.

There is a dynamic equilibrium that maintains a constant and controlled supply of glucose to the tissues, whilst maintaining blood glucose in a narrow range, in both the fed and fasting state. This balance is primarily dependent on the hormonal control of glucose uptake by insulin into the muscles in the fed state, and by glucagon and counter-regulatory hormones leading to glucose release from the liver in the fasted state. If a child presents with abnormal blood glucose control, an understanding of the basic physiology of glucose metabolism can be a valuable guide for both diagnosis and further management.

Summary It has been known for centuries that warmth is important for the newborn. In the 1950s, randomized controlled trials showed that keeping babies warm significantly reduced neonatal mortality. Technology has improved our ability to keep even the most immature baby warm, but there is evidence that infants still become cold during resuscitation and that most units are not achieving the British Association of Perinatal Medicine/Royal College of Paediatrics and Child Health standard of an admission temperature of at least 36 °C. A low temperature on admission has been independently associated with increased mortality in the preterm infant. Preventing evaporation, with the use of a plastic bag, while the baby is on the resuscitaire can abolish hypothermia on admission. There are no studies that show any difference in outcome for preterm babies nursed in incubators compared with those under radiant heaters. Care must be taken to reduce the very high transepidermal water losses under radiant heaters. The way a baby interacts with its environment is always changing and, whatever temperature and humidity settings are first used, it is necessary to monitor the thermal balance continuously. The continuous measurement and display of a central and a peripheral temperature gives an early indication of cold stress before there is any fall in the baby's core temperature.

Mailing Address: Fernando Antibas Atik – The Cleveland Clinic Foundation – 9500 Euclid Avenue H35 Cleveland, Ohio 44195 – USA Email: fernandoatik@aol.com Received in 06/07/05 Accepted in 12/09/05 The surgical treatment of hypoplastic left heart syndrome is still a challenge. Few selected large volume centers that adopted protocols focused on understanding of post-Norwood pathophysiology have reduced their mortality rates to around 15%. The inherent inefficacy of the parallel circulation in Norwood operation lends itself to problems related to postoperative management of these patients crucially revolving around keeping a balance between systemic blood flow (Qs) and pulmonary blood flow (Qp). This paper describes the physiology of the Norwood principle, the importance of an adequate hemodynamic assessment, to guide the different postoperative management options.

The 1952 Copenhagen poliomyelitis epidemic provided extraordinary challenges in applied physiology. Over 300 patients developed respiratory paralysis within a few weeks, and the ventilator facilities at the infectious disease hospital were completely overwhelmed. The heroic solution was to call upon 200 medical students to provide round-the-clock manual ventilation using a rubber bag attached to a tracheostomy tube. Some patients were ventilated in this way for several weeks. A second challenge was to understand the gas exchange and acid-base status of these patients. At the onset of the epidemic, the only measurement routinely available in the hospital was the carbon dioxide concentration in the blood, and the high values were initially misinterpreted as a mysterious “alkalosis.” However, pH measurements were quickly instituted, the Pco2was shown to be high, and modern clinical respiratory acid-base physiology was born. Taking a broader view, the problems highlighted by the epidemic underscored the gap between recent advances made by physiologists and their application to the clinical environment. However, the 1950s ushered in a renaissance in clinical respiratory physiology. In 1950 the coverage of respiratory physiology in textbooks was often woefully inadequate, but the decade saw major advances in topics such as mechanics and gas exchange. An important development was the translation of the new knowledge from departments of physiology to the clinical setting. In many respects, this period was therefore the beginning of modern clinical respiratory physiology.

Summary Although the majority of newly born babies will establish normal respiration and circulation without help, up to 1–2% may require some resuscitation. Although the word ‘physiology' induces narcolepsy in many doctors, the fetal and perinatal physiology governs many of the practical aspects of newborn resuscitation and is the basis for the differences from resuscitation later in life. Newly born babies lose heat faster than at any other time in life and until the first breath, the newborn lungs are completely filled with fluid, which is a state experienced during resuscitation at no other time. An understanding of the normal and abnormal perinatal physiology is important in appreciating the practical differences in the approach to caring for any baby in need of resuscitation and also in avoiding actions that may be detrimental in the longer term.

Summary Recent developments in the techniques available to measure lung function in children have greatly improved our understanding of lung development in both health and disease. In everyday clinical practice, lung function tests can provide objective information about the severity and progression of disease and the response to treatment. Although spirometry remains the most useful and widely used test, newer techniques, such as specific airways resistance and resistance measured by the interrupter technique, allow children who are too young to co-operate with spirometry to be tested. This is of great importance as it is increasingly recognized that many chronic respiratory illnesses in older children and adults have their origins in early life. This paper will describe the basic physiology of some standard tests and some of the newer tests that are increasing our understanding of lung disease in children.

The most important function of the skin is to provide a protective barrier between the body and the environment. It limits loss of body water, prevents absorption of noxious agents and protects against physical trauma. The epidermal barrier begins to develop in mid-gestation and is fully formed by about 32 weeks gestation. In the extremely preterm infant, it is poorly formed and functionally weak. Exposure to air after birth accelerates epidermal development. Transepidermal water loss is high in the immature infant, causing difficulties in fluid balance and temperature control. The percutaneous absorption of topically applied agents may lead to accidental poisoning. Adhesive trauma strips the epidermis, predisposing to infection. These problems can be minimized by limiting the use of skin probes and adhesive tape, nursing the infant in a high ambient humidity and sparing use of aqueous chlorhexidine as an antiseptic. The routine use of emollients or skin coverings is not recommended.

in an editorial in the March 2012 issue of the Journal of Applied Physiology , Nieman ([11][1]) highlighted a topic that has simmered below the surface for decades, i.e., how does the lung acinus expand with lung inflation. Indeed, the topic may be the last frontier of gross anatomy, but it is one

The first description on the importance of right ventricular (RV) function comes from the English physician Sir William Harvey in 1616 in his seminal treatise, De Motu Cordis. He recognized that “the right ventricle may be said to be made for the sake of transmitting blood through the lungs, not for nourishing them” [1]. For almost four centuries, emphasis in physiology and cardiology was placed on left ventricular (LV) physiology, overshadowing the study of the RV, which could still be characterized as “the neglected ventricle” [2]. The intriguing hypothesis that systemic circulation could be adequately maintained without RV contractile function, as in total cavopulmonary connection, underestimated the role of the right heart [3]. During the last two decades, clinicians, mainly cardiologists and cardiac surgeons, as well as researchers, recognized the importance of right-sided function in left-sided heart failure, RV myocardial infarction, congenital heart disease (CHD), and pulmonary arterial hypertension (PAH). Advances in invasive and noninvasive imaging have dramatically improved our understanding on the anatomy and physiology of the right heart and the pulmonary circulation in both acquired and CHD. In this chapter, we describe, from a clinical perspective, the applied physiology of the normal RV, the adaptive and maladaptive pathophysiology that leads to the development of right heart failure under various conditions, and molecular aspects of RV remodeling and failure.

The provision of complex medical care in the intensive care unit (ICU) environment is challenging as the established goals of intensive care are to reduce the morbidity and mortality related to critical illness, maintain organ function, and restore health. Despite technological advances, the prevalence of death in the ICU remains a serious problem. Even if it is unlikely that intensive care medicine is recognized as an evidence-based process, the present reality reveals that scientific proof regarding patient management is very rare [1]. However, this medicine is pathophysiology based, and it necessitates the monitoring of physiological abnormalities to treat the patient. Indeed, outcome prediction models measuring the severity of illness of patients admitted to the ICU use physiological variables to predict hospital mortality. For instance, from the clinical and medical management perspective, the state-of-the-art Simplified Acute Physiology Score (SAPS) model is frequently used. In the present state of medical knowledge, it is important to account for human physiology when treating critically ill patients, as these patients often present with circulatory failure. Understanding the properties of cardiovascular physiology is an excellent example of how general principles are useful in comprehending hemodynamic instability and shock states [2]. Therefore, from a physiological point of view, mastering the cardiovascular physiology and identifying the pathophysiological mechanisms and archetype involved in shock allow the physician to manage each situation according to the specific characteristics of the state of the patient. In the first half of the 20th century, there was considerable confusion among physiologists regarding the combined role of the heart and vasculature in determining flow and pressure in the cardiovascular system [3]. Currently, our understanding of these subjects is constantly evolving. As part of the present special issue, respected researchers and physiologists provide an outline of the important advances in cardiovascular physiology and the great progress made in recent years within this discipline. The present papers take a deeper look at selected physiological principles and main beliefs that are the basis of intensive care medicine. In fact, the present papers investigate physiological principles using various techniques described in humans and animal experimentation. In addition, in the present issue, the use of mathematical and simulated models as alternative methods is highlighted as a potential way to study specific cases in diverse vessels. These papers, which describe numerical simulations of flow, ranging from the geometry of steady flow in rigid vessels to unsteady flow with elastic vessel walls, deserve further attention as several flow and wall models are compared. Finally, all of these works reinforce our use of these principles in clinical decision-making. Thus, it must be established and accepted that specific cardiovascular physiology concepts are essential if and only if an appropriate form of intervention or treatment could be administered based on this knowledge. Indeed, it is important to note that our way of thinking about cardiovascular physiology in the ICU may sometimes be imperfect as views and understanding need to evolve [4]. Certainly, in the present state of knowledge, the most significant advantage of mastering cardiovascular physiology in critically ill patients is the capability to recommend new methods of treatment for shock. Karim Bendjelid Bruno Levy Alain Broccard

In the embryo, blood cell formation (haemopoiesis) originates in the yolk sac, and subsequently takes place in the fetal liver and, to a lesser degree, in the spleen. From the fifth month of fetal life, haemopoiesis develops in the bone marrow, which is the principal haemopoietic organ by the time of birth.