Pulmonary Gas Exchange
The exchange of OXYGEN and CARBON DIOXIDE between alveolar air and pulmonary capillary blood that occurs across the BLOOD-AIR BARRIER.
Ventilation-Perfusion Ratio
The ratio of alveolar ventilation to simultaneous alveolar capillary blood flow in any part of the lung. (Stedman, 25th ed)
Noble Gases
Elements that constitute group 18 (formerly the zero group) of the periodic table. They are gases that generally do not react chemically.
Blood Gas Analysis
Arrhythmia, Sinus
Irregular HEART RATE caused by abnormal function of the SINOATRIAL NODE. It is characterized by a greater than 10% change between the maximum and the minimum sinus cycle length or 120 milliseconds.
Oxygen
An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.
Carbon Dioxide
A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.
Pulmonary Diffusing Capacity
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.
Partial Pressure
The pressure that would be exerted by one component of a mixture of gases if it were present alone in a container. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Respiratory Dead Space
That part of the RESPIRATORY TRACT or the air within the respiratory tract that does not exchange OXYGEN and CARBON DIOXIDE with pulmonary capillary blood.
Oxygen Consumption
Respiration
The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (= OXYGEN CONSUMPTION) or cell respiration (= CELL RESPIRATION).
Gases
The vapor state of matter; nonelastic fluids in which the molecules are in free movement and their mean positions far apart. Gases tend to expand indefinitely, to diffuse and mix readily with other gases, to have definite relations of volume, temperature, and pressure, and to condense or liquefy at low temperatures or under sufficient pressure. (Grant & Hackh's Chemical Dictionary, 5th ed)
Tidal Volume
Lung
Pulmonary Ventilation
Smoke Inhalation Injury
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.
Pulmonary Edema
Excessive accumulation of extravascular fluid in the lung, an indication of a serious underlying disease or disorder. Pulmonary edema prevents efficient PULMONARY GAS EXCHANGE in the PULMONARY ALVEOLI, and can be life-threatening.
Physical Exertion
Expenditure of energy during PHYSICAL ACTIVITY. Intensity of exertion may be measured by rate of OXYGEN CONSUMPTION; HEAT produced, or HEART RATE. Perceived exertion, a psychological measure of exertion, is included.
Hepatopulmonary Syndrome
A syndrome characterized by the clinical triad of advanced chronic liver disease, pulmonary vascular dilatations, and reduced arterial oxygenation (HYPOXEMIA) in the absence of intrinsic cardiopulmonary disease. This syndrome is common in the patients with LIVER CIRRHOSIS or portal hypertension (HYPERTENSION, PORTAL).
Hyperventilation
A pulmonary ventilation rate faster than is metabolically necessary for the exchange of gases. It is the result of an increased frequency of breathing, an increased tidal volume, or a combination of both. It causes an excess intake of oxygen and the blowing off of carbon dioxide.
Respiration, Artificial
Any method of artificial breathing that employs mechanical or non-mechanical means to force the air into and out of the lungs. Artificial respiration or ventilation is used in individuals who have stopped breathing or have RESPIRATORY INSUFFICIENCY to increase their intake of oxygen (O2) and excretion of carbon dioxide (CO2).
Extravascular Lung Water
Water content outside of the lung vasculature. About 80% of a normal lung is made up of water, including intracellular, interstitial, and blood water. Failure to maintain the normal homeostatic fluid exchange between the vascular space and the interstitium of the lungs can result in PULMONARY EDEMA and flooding of the alveolar space.
Cardiac Output
Exercise Test
Anoxia
Relatively complete absence of oxygen in one or more tissues.
Hemodynamics
Respiratory Distress Syndrome, Adult
A syndrome characterized by progressive life-threatening RESPIRATORY INSUFFICIENCY in the absence of known LUNG DISEASES, usually following a systemic insult such as surgery or major TRAUMA.
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.
Bicycling
The use of a bicycle for transportation or recreation. It does not include the use of a bicycle in studying the body's response to physical exertion (BICYCLE ERGOMETRY TEST see EXERCISE TEST).
Pulmonary Alveoli
Lung Diseases
Pathological processes involving any part of the LUNG.
Vital Capacity
Spirometry
Measurement of volume of air inhaled or exhaled by the lung.
Respiratory Transport
Dogs
Lactic Acid
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.