Inspiratory Capacity: The maximum volume of air that can be inspired after reaching the end of a normal, quiet expiration. It is the sum of the TIDAL VOLUME and the INSPIRATORY RESERVE VOLUME. Common abbreviation is IC.Expiratory Reserve Volume: The extra volume of air that can be expired with maximum effort beyond the level reached at the end of a normal, quiet expiration. Common abbreviation is ERV.Dyspnea: Difficult or labored breathing.Lung Volume Measurements: Measurement of the amount of air that the lungs may contain at various points in the respiratory cycle.Bronchodilator Agents: Agents that cause an increase in the expansion of a bronchus or bronchial tubes.Pulmonary Disease, Chronic Obstructive: A disease of chronic diffuse irreversible airflow obstruction. Subcategories of COPD include CHRONIC BRONCHITIS and PULMONARY EMPHYSEMA.Vital Capacity: The volume of air that is exhaled by a maximal expiration following a maximal inspiration.Total Lung Capacity: The volume of air contained in the lungs at the end of a maximal inspiration. It is the equivalent to each of the following sums: VITAL CAPACITY plus RESIDUAL VOLUME; INSPIRATORY CAPACITY plus FUNCTIONAL RESIDUAL CAPACITY; TIDAL VOLUME plus INSPIRATORY RESERVE VOLUME plus functional residual capacity; or tidal volume plus inspiratory reserve volume plus EXPIRATORY RESERVE VOLUME plus residual volume.Forced Expiratory Volume: Measure of the maximum amount of air that can be expelled in a given number of seconds during a FORCED VITAL CAPACITY determination . It is usually given as FEV followed by a subscript indicating the number of seconds over which the measurement is made, although it is sometimes given as a percentage of forced vital capacity.Scopolamine Derivatives: Analogs or derivatives of scopolamine.Respiratory Function Tests: Measurement of the various processes involved in the act of respiration: inspiration, expiration, oxygen and carbon dioxide exchange, lung volume and compliance, etc.Functional Residual Capacity: The volume of air remaining in the LUNGS at the end of a normal, quiet expiration. It is the sum of the RESIDUAL VOLUME and the EXPIRATORY RESERVE VOLUME. Common abbreviation is FRC.Spirometry: Measurement of volume of air inhaled or exhaled by the lung.Respiratory Mechanics: The physical or mechanical action of the LUNGS; DIAPHRAGM; RIBS; and CHEST WALL during respiration. It includes airflow, lung volume, neural and reflex controls, mechanoreceptors, breathing patterns, etc.Albuterol: A short-acting beta-2 adrenergic agonist that is primarily used as a bronchodilator agent to treat ASTHMA. Albuterol is prepared as a racemic mixture of R(-) and S(+) stereoisomers. The stereospecific preparation of R(-) isomer of albuterol is referred to as levalbuterol.Exercise Tolerance: The exercise capacity of an individual as measured by endurance (maximal exercise duration and/or maximal attained work load) during an EXERCISE TEST.Pulmonary Ventilation: The total volume of gas inspired or expired per unit of time, usually measured in liters per minute.Tidal Volume: The volume of air inspired or expired during each normal, quiet respiratory cycle. Common abbreviations are TV or V with subscript T.Exercise Test: Controlled physical activity which is performed in order to allow assessment of physiological functions, particularly cardiovascular and pulmonary, but also aerobic capacity. Maximal (most intense) exercise is usually required but submaximal exercise is also used.Plethysmography: Recording of change in the size of a part as modified by the circulation in it.Diaphragm: The musculofibrous partition that separates the THORACIC CAVITY from the ABDOMINAL CAVITY. Contraction of the diaphragm increases the volume of the thoracic cavity aiding INHALATION.Ethanolamines: AMINO ALCOHOLS containing the ETHANOLAMINE; (-NH2CH2CHOH) group and its derivatives.Respiratory Muscles: These include the muscles of the DIAPHRAGM and the INTERCOSTAL MUSCLES.Administration, Inhalation: The administration of drugs by the respiratory route. It includes insufflation into the respiratory tract.Lung: Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.Cross-Over Studies: Studies comparing two or more treatments or interventions in which the subjects or patients, upon completion of the course of one treatment, are switched to another. In the case of two treatments, A and B, half the subjects are randomly allocated to receive these in the order A, B and half to receive them in the order B, A. A criticism of this design is that effects of the first treatment may carry over into the period when the second is given. (Last, A Dictionary of Epidemiology, 2d ed)Exercise: Physical activity which is usually regular and done with the intention of improving or maintaining PHYSICAL FITNESS or HEALTH. Contrast with PHYSICAL EXERTION which is concerned largely with the physiologic and metabolic response to energy expenditure.Double-Blind Method: A method of studying a drug or procedure in which both the subjects and investigators are kept unaware of who is actually getting which specific treatment.Cellular Structures: Components of a cell.Inhalation: The act of BREATHING in.Airway Obstruction: Any hindrance to the passage of air into and out of the lungs.Sleep Apnea Syndromes: Disorders characterized by multiple cessations of respirations during sleep that induce partial arousals and interfere with the maintenance of sleep. Sleep apnea syndromes are divided into central (see SLEEP APNEA, CENTRAL), obstructive (see SLEEP APNEA, OBSTRUCTIVE), and mixed central-obstructive types.Congresses as Topic: Conferences, conventions or formal meetings usually attended by delegates representing a special field of interest.Education: Acquisition of knowledge as a result of instruction in a formal course of study.Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Powders: Substances made up of an aggregation of small particles, as that obtained by grinding or trituration of a solid drug. In pharmacy it is a form in which substances are administered. (From Dorland, 28th ed)Continuous Positive Airway Pressure: A technique of respiratory therapy, in either spontaneously breathing or mechanically ventilated patients, in which airway pressure is maintained above atmospheric pressure throughout the respiratory cycle by pressurization of the ventilatory circuit. (On-Line Medical Dictionary [Internet]. Newcastle upon Tyne(UK): The University Dept. of Medical Oncology: The CancerWEB Project; c1997-2003 [cited 2003 Apr 17]. Available from: http://cancerweb.ncl.ac.uk/omd/)Intermittent Positive-Pressure Breathing: Application of positive pressure to the inspiratory phase of spontaneous respiration.Positive-Pressure Respiration: A method of mechanical ventilation in which pressure is maintained to increase the volume of gas remaining in the lungs at the end of expiration, thus reducing the shunting of blood through the lungs and improving gas exchange.Air Pressure: The force per unit area that the air exerts on any surface in contact with it. Primarily used for articles pertaining to air pressure within a closed environment.Sleep Apnea, Obstructive: A disorder characterized by recurrent apneas during sleep despite persistent respiratory efforts. It is due to upper airway obstruction. The respiratory pauses may induce HYPERCAPNIA or HYPOXIA. Cardiac arrhythmias and elevation of systemic and pulmonary arterial pressures may occur. Frequent partial arousals occur throughout sleep, resulting in relative SLEEP DEPRIVATION and daytime tiredness. Associated conditions include OBESITY; ACROMEGALY; MYXEDEMA; micrognathia; MYOTONIC DYSTROPHY; adenotonsilar dystrophy; and NEUROMUSCULAR DISEASES. (From Adams et al., Principles of Neurology, 6th ed, p395)Chest Wall Oscillation: A respiratory support system used to remove mucus and clear airway by oscillating pressure on the chest.Pressure: A type of stress exerted uniformly in all directions. Its measure is the force exerted per unit area. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Lung Diseases: Pathological processes involving any part of the LUNG.Lung Diseases, Obstructive: Any disorder marked by obstruction of conducting airways of the lung. AIRWAY OBSTRUCTION may be acute, chronic, intermittent, or persistent.Lung Diseases, Interstitial: A diverse group of lung diseases that affect the lung parenchyma. They are characterized by an initial inflammation of PULMONARY ALVEOLI that extends to the interstitium and beyond leading to diffuse PULMONARY FIBROSIS. Interstitial lung diseases are classified by their etiology (known or unknown causes), and radiological-pathological features.Residual Volume: The volume of air remaining in the LUNGS at the end of a maximal expiration. Common abbreviation is RV.Macrophage Activation: The process of altering the morphology and functional activity of macrophages so that they become avidly phagocytic. It is initiated by lymphokines, such as the macrophage activation factor (MAF) and the macrophage migration-inhibitory factor (MMIF), immune complexes, C3b, and various peptides, polysaccharides, and immunologic adjuvants.Acute Lung Injury: A condition of lung damage that is characterized by bilateral pulmonary infiltrates (PULMONARY EDEMA) rich in NEUTROPHILS, and in the absence of clinical HEART FAILURE. This can represent a spectrum of pulmonary lesions, endothelial and epithelial, due to numerous factors (physical, chemical, or biological).Macrophages: The relatively long-lived phagocytic cell of mammalian tissues that are derived from blood MONOCYTES. Main types are PERITONEAL MACROPHAGES; ALVEOLAR MACROPHAGES; HISTIOCYTES; KUPFFER CELLS of the liver; and OSTEOCLASTS. They may further differentiate within chronic inflammatory lesions to EPITHELIOID CELLS or may fuse to form FOREIGN BODY GIANT CELLS or LANGHANS GIANT CELLS. (from The Dictionary of Cell Biology, Lackie and Dow, 3rd ed.)Multiple Trauma: Multiple physical insults or injuries occurring simultaneously.Phenylmercury Compounds: Organic mercury compounds in which the mercury is attached to a phenyl group. Often used as fungicides and seed treatment agents.Smoke Inhalation Injury: Pulmonary injury following the breathing in of toxic smoke from burning materials such as plastics, synthetics, building materials, etc. This injury is the most frequent cause of death in burn patients.Lung Injury: Damage to any compartment of the lung caused by physical, chemical, or biological agents which characteristically elicit inflammatory reaction. These inflammatory reactions can either be acute and dominated by NEUTROPHILS, or chronic and dominated by LYMPHOCYTES and MACROPHAGES.