Lung

Lung
source
Name	Lung
Latin	Pulmo
Caption	Human lungs
System	Respiratory system
Location	Thoracic cavity
Precursor	Respiratory diverticulum
Arteries	Pulmonary arteries
Veins	Pulmonary veins
Nerves	Vagus nerve

Lung The lung is a paired respiratory organ located in the thoracic cavity responsible for gas exchange and acid–base homeostasis. It interacts with the heart, diaphragm, pleura, trachea and bronchial tree to support oxygen delivery and carbon dioxide removal. Major figures and institutions have advanced lung science through research and clinical practice.

Structure and anatomy

The gross anatomy of the lung includes lobes, bronchi, bronchioles, alveolar ducts and alveoli adjacent to the mediastinum, diaphragm, pleura and pericardium, and is supplied by pulmonary and bronchial vasculature studied in texts from Gray's Anatomy contributors and at centers like Mayo Clinic and Johns Hopkins Hospital. Each lung is enveloped by visceral and parietal pleura; the right lung classically has three lobes and the left lung two lobes with a cardiac notch, as described in surgical atlases used at Cleveland Clinic and Massachusetts General Hospital. The bronchial tree branches from the trachea into primary, secondary and tertiary bronchi; microscopic structure includes conducting airways lined by ciliated pseudostratified epithelium studied in histology courses at Harvard Medical School and Stanford School of Medicine. The alveolar-capillary interface comprises type I and type II pneumocytes, capillary endothelium and interstitium—a microanatomy explored in research from the National Institutes of Health and laboratories at Imperial College London and Karolinska Institutet. Lymphatic drainage follows bronchopulmonary, tracheobronchial and paratracheal nodes evaluated during staging systems developed by teams at Memorial Sloan Kettering Cancer Center and Royal Marsden Hospital. Surface markings, fissures and bronchopulmonary segments are key for thoracic surgeons at Guy's and St Thomas' NHS Foundation Trust and Royal Brompton Hospital. Vascular relations include pulmonary arteries carrying deoxygenated blood and pulmonary veins returning oxygenated blood to the left atrium, an arrangement detailed in cardiovascular texts from European Society of Cardiology and American Heart Association committees.

Development and embryology

Lung development originates from the respiratory diverticulum during the fourth week of embryogenesis, a process reviewed in embryology curricula at University College London and Yale School of Medicine. Branching morphogenesis yields bronchial architecture through signaling pathways including FGF, BMP, SHH and WNT investigated by groups at Max Planck Institute and Cold Spring Harbor Laboratory. Alveolarization proceeds postnatally influenced by factors studied at Children's Hospital of Philadelphia and Great Ormond Street Hospital for Children; prematurity and surfactant deficiency were central to discoveries by researchers at Columbia University Irving Medical Center and University of Pennsylvania Perelman School of Medicine. Congenital anomalies such as congenital diaphragmatic hernia, pulmonary hypoplasia and tracheoesophageal fistula have been characterized in reports from Royal College of Surgeons conferences and registries from Centers for Disease Control and Prevention.

Physiology and function

Gas exchange across the alveolar-capillary membrane is governed by diffusion principles articulated by investigators at University of Cambridge and ETH Zurich. Pulmonary ventilation and perfusion matching (V/Q) underlie oxygen uptake and carbon dioxide elimination studied in physiology departments at University of Oxford and McGill University. Control of breathing involves central chemoreceptors in the medulla and peripheral chemoreceptors in the carotid bodies, topics advanced by researchers affiliated with Salk Institute and Max Planck Society. Surfactant, produced by type II pneumocytes, reduces surface tension—a discovery linked to clinicians at Vermont Lung Center and laboratories at Duke University School of Medicine. Pulmonary circulation exhibits low resistance and high compliance properties examined in hemodynamic research from European Respiratory Society and American Thoracic Society. Mucociliary clearance and innate immune defenses were elucidated by teams at Pasteur Institute and Institut Curie, and alveolar macrophage biology has been a focus at Fred Hutchinson Cancer Center and Scripps Research.

Diseases and disorders

Common and severe lung diseases include chronic obstructive pulmonary disease, asthma, pneumonia, tuberculosis, pulmonary embolism, pulmonary hypertension, interstitial lung disease, acute respiratory distress syndrome and lung cancer; these conditions are central to clinical guidelines from World Health Organization, National Health Service and American Lung Association. Occupational and environmental lung diseases such as asbestosis, silicosis and coal worker pneumoconiosis were pivotal in public health actions by International Labour Organization and litigation involving firms documented in legal histories. Infectious agents like Mycobacterium tuberculosis and agents responsible for pandemics studied at World Health Organization and Centers for Disease Control and Prevention have shaped respiratory medicine. Genetic and rare disorders including cystic fibrosis, alpha-1 antitrypsin deficiency and primary ciliary dyskinesia have been characterized by research centers at University of Toronto and University of North Carolina School of Medicine.

Diagnosis and imaging

Pulmonary diagnosis employs chest radiography, computed tomography, magnetic resonance imaging, positron emission tomography and ultrasonography as used in diagnostic pathways at Royal College of Radiologists and imaging consortia at Radiological Society of North America. Spirometry, lung volume measurement, diffusing capacity testing and arterial blood gas analysis are standard functional tests established in protocols from European Respiratory Society and American Thoracic Society. Bronchoscopy, endobronchial ultrasound and thoracoscopy allow direct visualization and sampling in services provided at Mount Sinai Hospital and Hospital for Special Surgery. Staging systems for lung cancer, including TNM classifications, were developed by panels including experts from Union for International Cancer Control and International Association for the Study of Lung Cancer.

Treatment and management

Management spans prevention, pharmacotherapy, interventional procedures, rehabilitation and transplantation with major contributions from World Health Organization guidelines, drug approvals by Food and Drug Administration and trials coordinated by networks at National Institutes of Health and European Medicines Agency. Pharmacologic treatments include bronchodilators, corticosteroids, antibiotics, antifibrotics and targeted therapies developed by pharmaceutical companies and academic collaborations at University of California, San Francisco and University of Washington. Surgical treatments include lobectomy, pneumonectomy and segmentectomy performed at specialist centers like Royal Brompton Hospital and Memorial Sloan Kettering Cancer Center; lung transplantation programs have been refined at Cleveland Clinic and UCLA Health. Supportive care includes oxygen therapy, noninvasive ventilation and pulmonary rehabilitation delivered in healthcare systems such as NHS England and institutions endorsed by American Thoracic Society standards.

Category:Organs