Functions of the Respiratory System
Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal in Principles of Physiology for the Anaesthetist, 2020
The primary function of the lungs is gas exchange, but there are also non-respiratory functions, including blood filter, acid–base regulation, phonations, and pulmonary defence functions. The structures of the respiratory system can be divided into conducting airways and the respiratory zone. The function of conducting airways is to permit bulk flow of air to and from the respiratory zone and to warm, humidify and filter the inspired air before it reaches the respiratory zone. The respiratory zone begins with the respiratory bronchioles, the first airways to have alveoli in their walls, through the alveolar ducts to the alveolar sacs. The thorax, containing the lungs, is separated from the abdomen by the diaphragm. Contraction of the diaphragm increases the vertical dimension of the chest by pushing the abdominal contents down. The lungs lie within the thorax, covered by the visceral pleura and separated from the parietal pleura on the inside of the chest wall by the (potential) intrapleural space.
The mediastinum and the hila
Paul F. Jenkins in Making Sense of the Chest X-ray, 2013
This chapter considers the mediastinum in separate geographic departments and explains the anatomical components of each. The anatomical boundaries of the mediastinum are the thoracic inlet superiorly, the diaphragm inferiorly and the parietal pleura on both sides laterally. The thymus is an anterior mediastinal structure but thymomas often extend up into the superior mediastinum. Indeed, they may appear as predominantly superior mediastinal masses. Mediastinal lymph node enlargement is the most common chest radiographic finding in Hodgkin’s disease and is seen on the initial chest X-ray of approximately 50 per cent of patients with this condition. The chest X-ray is commonly normal in aortic dissection and it is essential to maintain a high index of suspicion of this diagnosis. The chest X-ray is a fairly coarse tool in identifying hilar and mediastinal pathology and it is vital to consider a patient’s clinical presentation along with the radiographic appearances when determining the need for investigation.
Pleuritic chest pain
Sherif Gonem, Ian Pavord in Diagnosis in Acute Medicine, 2017
This chapter discusses 'pleuritic chest pain' that will be used to refer to any chest pain that is sharp, well localised and exacerbated by inspiration, regardless of its origin. Pain in general may be divided into three categories, namely somatic, visceral and neuropathic. Somatic pain arises from superficial structures such as the skin, ribs and intercostal muscles, as well as the parietal pleura and pericardium. Pleuritic chest pain refers to pain arising from pleural irritation. It is characterically sharp in nature, well localised and exacerbated by inspiration, and is thus a form of somatic pain, mediated by fast-conducting A-delta fibres. Since pain with very similar characteristics may result from pathology affecting the chest wall or pericardium, these conditions are best discussed together. Potentially life-threatening causes of pleuritic chest pain include pulmonary embolism, tension pneumothorax, pneumonia and empyema. Tension pneumothorax is an immediately life-threatening cause of pleuritic chest pain.
Primary Primitive Neuro-ectodermal Tumour of the Lung
Published in Acta Chirurgica Belgica, 2009
G. Verfaillie, A. Hoorens, J. Lamote
A case of intrapulmonary primitive neuro-ectodermal tumour (PNET) without thoracic wall involvement is presented in a 33-year-old man. PNET of the thoracopulmonary region, also called Askin tumour, is a rare undifferentiated sarcoma usually involving the thoracic wall. Primary intrapulmonary PNET without parietal pleura or thoracic wall involvement is very rare. The correlation between anatomo-pathological aspects and clinical imaging is emphasized, which is discussed in the light of the most recent literature.
The Pleura: A Combined Light Microscopic, Scanning, and Transmission Electron Microscopic Study in the Sheep. I. Normal Pleura
Published in Experimental Lung Research, 1983
Andrew T. Mariassy, Eric B. Wheeldon
The structural features of the ovine pleura are described using light, scanning, and transmission electron microscopy. Extensive sampling of the visceral and parietal pleura revealed considerable variation in both surface morphology and pleural interstitial anatomy. Variations of mesothelial surface were encountered and these were due to microvillar density and length. The pleural interstitium varied considerably in thickness, being relatively sparse in the anterior lung lobes, where respiratory excursion is least, and much more robust in the caudal lung lobes, where respiratory excursion is greatest. A similar correlation was observed with regard to the abundance and extent of the elastic meshwork embedded in the interstitium. The parietal pleura had openings which connected directly with the lymphatics in the underlying interstitium, thus forming a direct channel between the pleural cavity and the lymphatic system.
Effect of transpleural perfusion with oxygenated perfluorocarbon in a rat model of acute lung injury
Published in Experimental Lung Research, 2013
Jeong Su Cho, Yeong Dae Kim, Nari Shin, Chang Hun Lee, Sukki Cho, Sanghoon Jheon
Background: Despite advances in critical care, more effective methods of systemic oxygenation in patients with acute lung injury or acute respiratory distress syndrome are needed. The goal of this study was to determine if it is possible to increase systemic oxygenation by transpleural perfusion with oxygenated perfluorocarbon in animals with induced acute lung injury. Methods: Eighteen Sprague–Dawley rats were intubated, and acute lung injury was induced by aspiration of 0.1N HCl (1 mL/kg) through the tracheal tube. Inflow and outflow tubes were placed in the thoracic cavity and connected to a perfusion circuit containing a roller pump, warmer, and oxygenator. Rats in group I were not treated after aspiration of HCl, those in group II were perfused with oxygenated saline, and those in group III were perfused with oxygenated perfluorocarbon. Arterial blood gases were collected every 30 minutes for 180 minutes. At the last step of the experiments, pathological examination of the lungs and parietal pleura was performed. Results: PaO2 in group III was significantly higher than that in group I or II. PaCO2 in group III was significantly lower than that in the other two groups. Histological examination showed relatively well-delineated zones of inflammation-free coagulative necrosis of lung parenchyma in all groups. Conclusions: Transpleural perfusion with oxygenated perfluorocarbon in an animal model of induced acute lung injury resulted in a significant increase in systemic oxygenation and depletion of systemic carbon dioxide, and might be a useful method for improving systemic oxygenation in patients with acute lung injury.