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JOURNAL OF APPLIED Vol. 34, No. 4, April PHYSIOLOGY 1973. Glossary Plhhd in U.S.A. on respiration and gas exchange1 Prepared by Subcommittee for Respiration Professor H. Bartels, Chairman Medizinische Hochscule, Hanover, Physiologisches Institut, West Germany ProfessorP. Dejours Labora toire de Physiologic Respiratoire, Centre National de la Recherche ScientiJique, 67 Stasbourg 3, France ProfessorR. H. Kellogg Department of Physiology, School of Medicine, San Francisco, California University of California, University, Approved by International Union of Physiological Sciences Committee on Nomenclature, ProfessorHans Schaefer, Chairman, Heidelberg, 1971; and the International Commission of the IUPS for Kespiration Professor S. M. Tenney, Chairman, 1972 INTRODUCTORY Physiology, REMARKS The International Union of Physiological Sciences, following an idea of the late Professor Fenn, established a Committee on physiological nomenclature, later on called “Glossary Committee,” the respiration subgroup of which has prepared the following Glossary on terms of the physiol- In respiratory physiology, as in any other vital field, it follows naturally that new terms will arise continuouslysome to express wholly new ideas, and others to replace outmoded terms. It is the latter that are most troublesome in preparing a glossary. For a while they can appear appro- ogy of respiration. The aims of the Glossary are to stand- priately as synonyms, but sooner or later they become ardize the use of important and frequently used scientific terms and to improve, as one of the results of such standardizations, the documentation of physiological literature. HANS SCHAEFER, Chairman IUPS Glossary Committee (197 I> misleading and must be dropped. The reader must be on guard for expressions which may be in a transition stage and for which it is impossible to get unanimous agreement, even with a panel of experts. The same caution applies to symbols, some of which are employed with entirely different meanings in other fields, and some of which, even in respiratory physiology, could be ambiguous if taken out of context. S. M. TENNEY, Chairman International Commission of IUPS for Respiration Physiology ( 1972) sentences that follow describe the scope of the definition. ‘DEFINITIONS Each English. word of the Glossary appears in capitals French (I?) and German (G) equivalents and is defined in are given. The words that are cross-referenced are capitalized, tion and scope, antonyms (Ant.), synonyms (Abbr.), and symbols (Symb.) are given. Glossary Following the defini(Syn.), abbreviations Downloaded from http://jap.physiology.org/ by 10.220.33.1 on June 15, 2017 Professor J. Mead Department of Physiology, Harvard School of Public Health, Boston, Massachusetts 550 GLOSSARY ACIDEMIA: Acidernie (F); Azidamie (G). Any state of systemic arterial plasma in which the pH is significantly less than the normal value, 7.41 =t 0.02 in adult man at rest. Newborns, infants, and pregnant women show deviations from the ‘ ‘normal” figure, as do many birds and mammals. Ant. ALKALEMIA. -4CIDOSIS: Acidose (F); Azidose (G). The result of any process which by itself adds excess CO2 (respiratory acidosis) or nonvolatile acids (metabolic acidosis) to arterial blood. Acidemia does not necessarily result since compensating mechanisms (increase of HC03 in respiratory acidosis, increase of ventilation and consequently decrease of arterial CO2 in metabolic acidosis) may intervene to restore plasma pH to normal. Ant. ALKALOSIS. ,41 K SPACES (G). All contrasted : Espace alveolaire (F) ; Alveolarraum alveolar ducts, alveolar sacs, and with AIRWAYS. (-volumen) alveoli. To ATELECTASIS: of air spaces Acclimatation Morphological at high altitude. B l’altitude and physio- ALVEOLAR-ARTERIAL GAS PRESSURE DIFFERENCE : Difference de pression alveolo-arterielle (F) ; Alveolararterielle Gasdruckdifferenz (G). The difference in partial pressure of a gas (e.g., 02 or N2) in the alveolar gas spaces and that in the systemic arterial blood, measured in torr. Note that a negative difference indicates that the partial pressure is higher in arterial blood than it is in the alveolar gas spaces. Symb. For oxygen, as an example, PACT - Paoz; also sometimes symbolized AaDo2. ALVEOLAR PRESSURE : Pression alveolaire (F) ; Alveolardruck (G). Total gas pressure in alveoli commonly expressed relative to atmospheric pressure in cm H20. Symb. P~lv. ANATOMICAL DEAD SPACE: Espace mort anatomique (F); Anatomischer Totraum (G). Volume of the conducting airways down to the level where, during air breathing, gas exchange with blood can occur, a region probably situated at the entrance of the alveolar ducts. Symb. VD~,,~. APNEA: ApnCe (F) ; Apnoe - (G). Cessation of breathing. APNEUSIS: Apneusis (F); Apneusis (G). A ventilatory pattern in which the contraction of inspiratory muscle is intense and sustained. Apneusis is observed in a vagotomized cat whose rostra1 pons has been transected; an “apneustic center” located in the pons is thought to be responsible. GAS EXCHANGE Atblectasie (F); with elimination Atelektase (G). State of the gas phase. of collapse CONDITIONS : Conditions (G). Ambient temperature water vapor. These are the spirometer. Abbr. ATPS. BASE EXCESS: Exces de base (F) ; Baseniiberschuss (G). A measure of metabolic alkalosis or metabolic acidosis (negative values of base excess) expressed as the mEq of strong acid or strong alkali required to titrate a sample of 1 liter of blood to a pH of 7.40. The titration is made with the blood sample kept at 37’ C, oxygenated, and equilibrated at PCO~ of 40 torr. Abbr. BE. BLOOD ATPS (F) ; ATPS Bedingungen and pressure, saturated with conditions existing in a water BUFFERING CAPACITY: (F) ; Blutpufferkapazitat (G). that can be made to combine blood. The normal capacity practice it is estimated as the and the anionic charges on proteins. To a much lesser extent are included. BOHR Valeur tampon du sang The maximum mEq of H+ with the solutes in 1 liter of is 45-53 mEq/liter, and in sum of the bicarbonate ions the hemoglobin and plasma phosphate and other buffers EFFECT: Effet Bohr (F); Bohr-Effekt (G). Dependence of oxygen saturation of hemoglobin on H+ concentration. Originally Bohr et al. (1904) described only the effect of PCOZ changes on oxygen saturation. The more usual practice now is to relate the effect to changes in H+ concentration (or pH). An increase in H+ concentration decreases the oxygen saturation of hemoglobin. A decrease of the pH value from 7.4 to 7.3 at 40 mm Hg oxygen pressure decreases the oxygen saturation by 6%, or approximately 1.2 ml 02/100 ml blood (oxygen capacity 20 ml O&O0 ml blood) in man. The effect is pronounced in the capillaries of working muscles (including heart muscle) and in the maternal and fetal exchange vessels of the placenta. The Bohr effect is generally expressed as Alog PoJApH at a given oxygen saturation. For human blood at lO--90% oxygen saturation the quotient at 37” C is 0.48 for a ApH of 0.1 unit. BREATH HOLDING: ApnCe volontaire (F) ; Atemanhalten (willkiirlich) (G) . Ap nea, usually, but not necessarily, with a closed glottis. This covers voluntary apnea, which when maximally prolonged is terminated by an involuntary breaking point, and diving breath holding, which in some seals or whales may last more than 1 hr. BREATHING PATTERN: Regime ventilatoire (F) ; Atemform, -art (G). A general term designating the characteristics the ventilatory activity, e.g., tidal volume, frequency breathing, and shape of the volume-time curve. BREUER-HERING REFLEXES : Reflexes de (F) ; Hering-B reuer Reflexe (G). Ventilatory nating in the lungs. The reflex arcs are formed Breuer-Hering reflexes origiby the pulmo- of of Downloaded from http://jap.physiology.org/ by 10.220.33.1 on June 15, 2017 ,4LTITUDE ACCLIMATIZATION: imatisation (G). (F) ; Hijhenakkl logical adjustments to a sojourn of any alkablood. AND ATPS AIRWAYS : Voies aeriennes (F) ; Atemwege (G). All passageways of the respiratory tract from mouth or nares down to and including respiratory bronchioles. To be contrasted with AIR SPACES. Symb. aw. ALKALOSIS: Alcalose (F) ; Alkalose (G). The result by itself, diminishes acids (respiratory process which, losis) or increases bases (metabolic alkalosis) in arterial Ant. ACIDOSIS. RESPIRATION ASPHYXIA: Asphyxie (F); Asphyxie (G). A condition of restricted gas exchange characterized by an increase of CO2 partial pressure above and a decrease of 02 pressure below normal values. Hypoventilation gives rise to an asphyxia throughout the body; regional asphyxia results when blood flow rate in an organ is low relative to metabolic rate of the organ. be ALKALEMIA: Alcalemie (F); Alkalamie (G). Any state of systemic arterial plasma in which the pH is significantly greater than the normal value, 7.41 & 0.02 in adult man at rest. Newborns, infants, and pregnant women show deviations from the ‘cnormal” figure, as do many birds and mammals. Ant. ACIDEMIA. ON GLOSSARY ON RESPIRATION AND GAS 551 EXCHANGE nary mechanoreceptors, the vagal afferent fibers, the respiratory centers, the medullospinal pathway, the motoneurons, and the respiratory muscles. The afferent link informs the respiratory centers of the volume state or of the rate of change of volume of the lungs. Three types of Breuer-Hering reflexes have been described: I) an inflation reflex in which lung inflation tends to inhibit inspiration and stimulate expiration; 2) a deflation reflex in which lung deflation tends to inhibit expiration and stimulate inspiration; and 3) a “paradoxical reflex,” described but largely disregarded by Breuer and Hering, in which sudden inflation may stimulate inspiratory muscles. BRONCHOSPIROMETRY: Bronchospirometrie (F) ; Bronchospirometrie (G). Technique for the study of the ventilation and gas exchanges of one lung, by introduction of a tube into the main bronchus of the right or the left lung. A doublelumen catheter (e.g., Carlens’s catheter) permits separate and simultaneous sampling of the gas of bo th lungs. CONDITIONS : Conditions BTPS (F) ; BTPS Bedingungen (G). Body temperature, barometric pressure, and saturated with water vapor. These are the conditions existing in the gas phase of the lungs. For man the normal temperature is taken as 37’ C, the pressure as the barometric pressure, and the partial pressure of water vapor, 47 torr. Abbr. BTPS. CARBAMINOHEMOGLOBIN: CarbaminohCmoglobine Carbaminohamoglobin (G). Hemoglobin in which amino groups (Hb-NH 2) are combined with carbon to form a carbamino compound (Hb-NH-COOplus (F) ; ionized dioxide H+). CARBON DIOXIDE-BLOOD (OR -PLASMA) EQUILIBRIUM CURVE: Courbe d’equilibre entre gaz carbonique et sang (ou plasma) (F); Kohlendioxid-Blut (oder -Plasma) Gleichgewichtskurve (G). Relation between total carbon dioxide concentration in blood (or separated or true plasma) and carbon dioxide pressure. In vitro curves are established by equilibration of blood or plasma (separated plasma) samples with gas mixtures containing varying fractions of carbon dioxide. The relation for oxygenated hemoglobin is obtained by equilibrating with an oxygen pressure of at least 200 torr. In vivo curves are established by inhaling various carbon dioxide fractions in inspired air for an appropriate equilibration time and measuring the actual carbon dioxide concentration and pressure in blood or true plasma samples. Because extravascular compartments are also equilibrated in vivo, at carbon dioxide pressures higher than 40 torr, the HCOsconcentration is lower than is measured in vitro. Abbr. CBEC, CPEC. CARBON DIOXIDE CONCENTRATION: Concentration du dioxide de carbone (F) ; Kohlendioxid-Konzentration (G). The amount of carbon dioxide that can be extracted by evacuation from an acidified sample of a liquid, including, in the case of blood, the physically dissolved COz, the bicarbonate, and the CO2 bound to hemoglobin. Ordinarily, it is expressed as ml CO2 (STPD) /lOO ml sample or mmole COJ liter. CO2 concentration should not be expressed as mEq COz/liter, since mEq is appropriate for HCOsbut not for CO2. Symb. CCO~. CARBON DIOXIDE dissociation du DISSOCIATION dioxide de carbone CURVE: Courbe (F) ; Kohlendioxid-Dis- de (G). See CARBON DIOXIDE-BLOOD EQUILIBRIUM CURVE. (OR CARBON DIOXIDE STORES: R&erves de dioxide de carbone (F); Kohlendioxidspeicher (G). Volumes of CO2 stored in all parts of the body as CO2, carbonic acid, carbonate, bicarbonate, and carbaminohemoglobin. In an adult human the CO2 stores amount to several liters. In a respiratory steady state the amount of CO2 produced by the cells is equal to the amount rejected by the lungs. Hence, the volume of CO2 stores remains constant. CARBONIC ANHYDRASE : Anhydrase carbonique (F) ; Karboanhydrase (G). An enzyme containing zinc which speeds the reaction CO2 + Hz0 \ H&03. Present in many tissues and red blood cells. In red blood cells a 2,090-fold acceleration of the hydrolysis of CO2 has been measured. In aqueous solutions the acceleration is approximately 13,000-fold. CARBOXYHEMOGLOBIN boxyhamoglobin associated with for CO is about : Carboxyhtmoglobine (F) ; Car(G). Hemoglobin in which the iron is carbon monoxide. The affinity of hemoglobin 300 times greater than for 02. Symb. HbCO. CHEST WALL : Paroi thoracique (F) ; Brust-(Thorax-) Wand (G). All structures outside the lungs which take part in breathing movements, i.e., rib cage, diaphragm, abdominal contents, and abdominal wall. Symb. w. CHEYNE-STOKES BREATHING : Respiration de CheyneStokes (F) ; Cheyne-Stokes’sche Atmung (G). Abnormal pattern of breathing consisting of progressively increasing, then progressively decreasing tidal movements followed by a period of apnea at relaxation volume before the pattern repeats. CHLORIDE SHIFT: Effet Hamburger (F) ; Chlorid Shift (G). Increase of red cell HCOaconcentration during COT uptake by the blood in peripheral capillaries results in a concentration gradient for HCOawhich favors diffusion of HCOZfrom the red cells into the plasma. In exchange Cl- diffuses from plasma into the red cells to maintain electroneutrality. This is known as the chloride shift. Because the amount of intracellular solute is increased by entrance of CO:! to form the HCOsin the cell and is not further changed by the HCOs--Clexchange, water also diffuses into the cell, which consequently swells very slightly. All these processes reverse when CO2 is lost in the pulmonary capillaries. Syn. HAMBURGER EFFECT. CHRISTIANSEN-DOUGLAS-HALDANE EFFECT: Effet Christiansen-Douglas-Haldane (F) ; Christiansen-DouglasHaldane-Effekt (G). Dependence of the carbon dioxide binding capability of the blood on the oxygen saturation of hemoglobin. An increase of the oxygen saturation decreases the carbon dioxide binding capability. In human blood at 40 torr carbon dioxide pressure and at 37’ C, fully deoxygenated blood binds approximately 6 ml CO& 00 ml blood more than fully oxygenated blood (oxygen capacity 20 ml OJlOO ml blood). The effect is explained by the decrease of the proton affinity of hemoglobin due to the oxygen uptake. During gas exchange in the lung of a resting subject the oxygen saturation increases from 75 to 980/, and consequently by the CDH Downloaded from http://jap.physiology.org/ by 10.220.33.1 on June 15, 2017 BTPS soziationskurve -PLASMA) 552 GLOSSARY effect efl’ect. 1.4 ml COJlOO Syn. HALDANE COLLATERAL VENTILATION Kollaterale Ventilation indirect pathways, e.g., anastomosing respiratory ml blood EFFECT. are liberated. : Ventilation (G) . Ventilation through pores in bronchioles. Abbr. CDH collaterale (F) ; of air spaces via alveolar septa, or CONDUCTANCE: reciprocal Conductance of RESISTANCE. (F) ; Leitfahigkeit Symb. G. (G). The COUNTERCURRENT GAS EXCHANGE : Echange gazeux par contrecourant (F) ; Gegenstromgasaustausch (G). Gas exchange between two media flowing in opposite directions. This type of exchange exists in many aquatic animals. Examples: I) between the blood flowing in the lamellae of the and the water flowing along the lamellae from 3uill filaments the buccal cavity to the opercular cavity; and 2) in the rete mirabile of the gas gland of some fish. This anatomical disposition facilitates the transfer of gas. CYANOSIS: Cyanose (F) ; Cyanose (G). Cyanosis is a condition characterized by a blue-purple color of the skin and mucosae. It is due to an abnormally high amount of deoxygenated hemoglobin in the capillaries of the skin and mucosae. According to Lundsgaard and Van Slyke (Medicine 2 : 1-76, 1923) cyanosis appears when capillary blood contains more than 5 g deoxygenated hemoglobin/100 ml blood. DECOMPRESSION SICKNESS : Ma1 de d&ompression (F); Dekompressionskrankheit (G). A group of illnesses characterized by formation of gas bubbles in blood or tissues, caused by release of physically dissolved gases when environmental pressure is decreased at sufficient rate and magnitude. Limb pain occurring shortly after emergence from a hyperbaric environment is the most common symptom. Illness may also result from abrupt exposure to very low pressures, as at high altitude, and symptoms other than limb pain may occur. The ideal treatment is immediate recompression; with some methods, high inspired oxygen fractions are employed. Decompression sickness should be distinguished from other illnesses associated with reduction of environmental pressure, of which the most important are those due to overdistention air embolism. Decompression of lung tissue, e.g., traumatic sickness is avoided by slow decompression. Nine days are required to decompress from 50 Ata pressure. The following terms are frequently employed as synonymous with decompression sickness but they are not recommended for use: bends, caisson disease, ma1 des caissons, Caisson Krankheit, compressed air illness. RESPIRATION AND GAS EXCHANGE DIFFUSING CAPACITY OF THE LUNG: Capacite de diffusion pulmonaire (F); Diffusionskapazitat der Lunge (G). Amount of gas (02, CO, COZ) commonly expressed as ml gas (STPD) diffusing between alveolar gas and pulmonary capillary blood per torr mean gas pressure difference per min, i.e., ml Oa/(min torr). Syn. Transfer factor, diffusion factor. Symb. DL, DL~~, DLCO~, DLCO. DYNAMIC COMPLIANCE : Compliance dynamique (F) ; Dynamische Compliance (G). The ratio of the tidal volume to the change in intrapleural pressure between the points of zero flow at the extremes of tidal volume in liters/cm Hz0 or ml/ cm H20. Since at the points of zero airflow at the extremes of tidal volume, volume acceleration is usually other than zero, and since, particularly in abnormal states, flow may still be taking place within lungs between regions which are exchanging volume, dynamic compliance may differ from static compliance, the latter pertaining to conditions of zero volume acceleration and zero gas flow throughout the lungs. In normal lungs at ordinary volumes and respiratory frestatic and dynamic compliance are the same. quencies, Symb. Cdyn. DYSPNEA: feeling Dyspnee of difficult ELASTANCE: COMPLIANCE; Symb. E. (F); Dyspnoe or labored Elastance (G). An unpleasant breathing. (F) ; Elastance (G). expressed in cm HzO/liter subjective The reciprocal or cm HzO/ml. of EQUIVALENT LUNG VOLUME : Volume pulmonaire Cquivalent (F); Aq uivalentes Lungenvolumen (G). A virtual volume of dilution, i.e., a hypothetical volume of pulmonary gas which accounts for change of alveolar partial pressures of CO2 (or 0,) when CO2 (or 0,) is added or subtracted from the gas phase. ELV is formed of the actual gas volume plus a hypothetical volume related to the fixation of CO2 (or 0,) in lung tissue and in pulmonary blood. ELV for CO:! is some 15 y0 greater than the actual lung volume. ELV for oxygen differs little from the actual lung volume. The existence of ELV lessens the Pcoz (and Paz) fluctuations which normally occur during the respiratory cycle. Abbr. ELV. EUPNEA: Eupn6e (F) ; breathing at rest. Eupnoe (G). Normal, comfortable FORCED EXPIRATORY VOLUME. Debit expiratoire maximal (F); Maximale Ausatmungskapazitat (G). Denotes the volume of gas which is exhaled in a given time interval during the execution of a forced vital capacity. Conventionally, the times used are 0.5, 0.75, or 1 set, symbolized, FE&s, These values are often expressed as a FEVo75, . FEVlO* . percent of the forced vital capacity; e.g., (FEVJVC) X 100. FLOW-VOLUME CURVE : Courbe debit-volume (F) ; Stromstarke-Volumen Kurve (G). Graph of instantaneous forced expiratory flow recorded at the mouth, against corresponding lung volume. When recorded over the full vital capacity, the curve includes maximum expiratory flow rates at all lung volumes in the VC range and is called a maximum expiratory flow-volume curve, abbreviated MEFV curve. A partial expiratory flow-volume curve is one which describes maxi- Downloaded from http://jap.physiology.org/ by 10.220.33.1 on June 15, 2017 CO,MPLIANCE : Compliance (F) ; Compliance (G). A measure of distensibility. Pulmonary compliance is given by the slope of a static volume-pressure curve at a point, or the linear approximation of a nearly straight portion of such a curve, expressed in liters/cm H20 or ml/cm HZO. Since the static volume-pressure characteristics of lungs are nonlinear (static compliance decreases as lung volume increases) and vary according to the previous volume history (static compliance at a given volume increases immediately after full inflation and decreases following deflation), careful specification of the conditions of measurement are necessary. Absolute values also depend on organ size. See also DYNAMIC COMPLIANCE. Symb. C. ON GLOSSARY ON RESPIRATION AND GAS EXCHANGE mum expiratory flow rate over a portion only. Abbr. PEFV. FUNCTIONAL Funktioneller SPACE. GAS EXCHANGE Symb. R. 553 of the vital capacity DEAD SPACE: Espace mort fonctionnel (F) ; Totraum (G). See PHYSIOLOGICAL DEAD RATIO : See RESPIRATORY QUOTIENT. GASP: Gasp ou secousse inspiratoire (F) ; Schnappatmung ventilatory movement consisting of an abrupt, transient inspiratory effort. (G). A sudden, HYPERCAPNIA: Hypercapnie (F) ; Hyperkapnie (G). Any state in which the systemic arterial carbon dioxide pressure is significantly above 40 torr. May occur when alveolar ventilation is inadequate for a given metabolic rate (HYPOVENTILATION) or during CO2 inhalation. HYPERCARBIA: PERCAPNIA. Hypercarbie (F) ; Hyperkarbie (G). See HY- HYPEROXIA: H yperoxie (F) ; Hyperoxie (G). A condition in which the inspired oxygen pressure is greater than that of air at sea level but not more than 1 Ata. HYPERVENTILATION: Hyperventilation (F) ; Hyperventilation (G). An alveolar ventilation which is excessive relative to the simultaneous metabolic rate. As a result the alveolar Pco2 is significantly reduced below the normal 40 torr. See HYPOCAPNIA. HYPOCAPNIA: H ypocapnie (F) ; Hypokapnie (G). Any state in which the systemic arterial carbon dioxide pressure is significantly below 40 torr, as in hyperventilation. HALDANE DANE HYPOCARBIA: POCAPNIA. HAMBURGER EFFECT: EFFECT. See CHRISTIANSEN-DOUGLAS-HAL- EFFECT: See CHLORIDE SHIFT. HEMOGLOBIN : HCmoglobine (F) ; Hamoglobin (G). A hemoproteid naturally occurring in most vertebrate blood, consisting of four polypeptide chains (the globulin) to each of which there is attached a heme group. The heme is made of four pyrrole rings and a divalent iron (Fe2+-protoporphyrin) which combines reversibly with molecular oxygen. Symb. Hb. HENDERSON-HASSELBALCH EQUATION : Equation de Henderson-Hasselbalch (F) ; Henderson-Hasselbalch Gleichung (G). This equation relates the different forms of carbon dioxide in plasma: pH = pd + log [total CO21 - S X s x PC02 PC02 = p& + log WC%-1 s x PC02 pKfl is the negative logarithm of the apparent first ionization constant of H&O3 corrected for the ratio of CO2 to H&03. S is the factor relating the partial pressure of carbon dioxide and the sum of the millimolar concentrations of dissolved carbon dioxide and carbonic acid in plasma (0.0301). Calculation of one of the three variables, pH, [HCOa-+], and Pco2, from the other two is valid only for a single phase such as the plasma or serum sample as separated from whole blood. There is no simple procedure for applying the HendersonHasselbalch equation to whole blood. HYPERBARIC OXYGENATION: Oxygenation hyperbare (F) ; Hyperbare Oxygenation (G). The condition produced by breathing a gas in which the partial pressure of oxygen is greater than that of 100% oxygen at sea level. This requires use of a pressure chamber. As a therapeutic technique, it is commonly used for the treatment of CO intoxication or gangrene associated with anaerobic bacteria. Hypocarbie (F) ; Hypokarbie (G). See HY- HYPOPNEA : HypopnCe (F) ; Hypopnoe (G). Decreased breathing in comparison with breathing at rest (less exact than and not to be confused with hypoventilation). HYPOVENTILATION: Hypoventilation (F) ; Hypoventilation (G). An alveolar ventilation which is small relative to the simultaneous metabolic rate so that alveolar Pco:! rises significantly above the normal 40 torr. HYPOXEMIA: HypoxCmie (F); Hypoxamie (G). A state in which the oxygen pressure and/or concentration in arterial and/or venous blood is lower than its normal value at sea level. Normal oxygen pressures at sea level are 85-100 torr in arterial blood and 37-44 torr in mixed venous blood. In adult humans the normal oxygen concentration is 17-23 ml O&O0 ml arterial blood; in mixed venous blood at rest it is 13-18 ml OJlOO ml blood. HYPOXIA: Hypoxie (F); Hypoxie (G). Any state in which the oxygen in the lung, blood, and/or tissues is abnormally low compared with that of normal resting man breathing air at sea level. If the POZ is low in the environment, whether because of decreased barometric pressure or decreased fractional concentration of 02, the condition is termed environmental hypoxia. Hypoxia when referring to the blood is terrned hypoxemia. Tissues are said to be hypoxic when their Po2 is low, even if there is no arterial hypoxemia, as in “stagnant hypoxia” which occurs when the local circulation is low compared to the local metabolism. INTRAPLEURAL Intrapleuraler PRESSURE : Pression Druck (G). See PLEURAL INTRAPULMONARY (F) ; Intrapulmonaler SURE. INTRATHORACIC Intrathorakaler intrapleurale PRESSURE. (F) ; PRESSURE : Pression intrapulmonaire Druck (G). See ALVEOLAR PRES- PRESSURE : Pression intrathoracique (F) ; Druck (G). See PLEURAL PRESSURE. Downloaded from http://jap.physiology.org/ by 10.220.33.1 on June 15, 2017 GAS POCKET: Poche de gaz (F) ; Gastasche (G). A term designating originally a gas cavity artifically created by an injection of gas into the subcutaneous tissue. Pneumoperitoneum, pneumothorax, a closed middle ear, subcutaneous emphysema, as examples, are analogous to artificial subcutaneous gas pockets. The gas composition in the pocket has been taken as an index of the partial pressures of gas in the surrounding tissue. 554 GLOSSARY ISOVOLUME volume relations inflation PRESSURE-FLOW pression-debit (F). Lines in the airways, measured (isovolume). Symb. IVPF CURVES: describing at equal curves. Courbes isopressure-flow degrees of lung MAXIMUM BREATHING CAPACITY: Capacite ventilatoire maximale (F) ; Maximale Atemkapazitat oder Atemgrenzwert (G). Maximal volume of air which can be breathed per minute by a subject breathing as quickly and as deeply as possible. This tiring lung function test is usually limited to 12-20 set, but given in liters (BTPS)/~~~. Abbr. MBC. Syn. Maximum voluntary ventilation (Abbr. MVV). MIXED VENOUS BLOOD: Sang veineux melEt (F) ; Gemischtvenijses Blut (G). Blood composed of a mixture of the venous blood from all systemic tissues in proportion to their venous returns. In the absence of abnormalities of the heart and great vessels, mixed venous blood is present in the main pulmonary artery. Blood samples drawn from right atrium or even right ventricle may be inadequately mixed. Symb. v. MOUNTAIN SICKNESS: Ma1 des montagnes (F) ; Hohenkrankheit (G). Pathological state induced by high altitude. Unacclimatized subjects, during their first few days at high headache, breathlessness, altitude, commonly experience sensorial or intellectual disturbances, sleeplessness, nausea, and eventually vomiting. This symptom complex is known as acute mountain sickness, or ‘CSoroche.” It is rare for these symptoms to last more than a few days at high altitude, and they are frequently relieved by inhalation of an Op-enriched mixture. Permanent residents at high altitude may develop chronic mountain sickness (Monge’s disease) in which alveolar ventilation is diminished, and signs and symptoms referable to the cardiovascular and central nervous systems appear. The relative hypoventilation aggravates the hypoxia, and right heart failure supervenes. Extreme polycythemia develops and hematocrit ratios, sometimes as high as 75%, are seen. The syndrome can be relieved by a return to sea level. MULLER’S MANEUVER: scher Versuch (G). Intrapulmonary and nary gas is expanded. Manoeuvre Inspiratory intrathoracic de Miiller (F); Miiller’effort with closed airway. pressures fall and pulmo- RESPIRATION by replacing NP to a certain certain pressure of substituted GEN POISONING. N 2 can AND GAS EXCHANGE extent with 02, but above a 02 there is a danger of OXYbe replaced by helium. NITROGEN WASHOUT CURVE: Elimination de l’azote (F) ; Stickstoffauswaschkurve (G). The curve obtained by plotting the fractional concentration of N2 in expired alveolar gas vs. time, for a subject switched from breathing ambient air to an inspired mixture of pure 02. A progressive decrease of Np concentration ensues which may be analyzed into two or more exponential components. Normally, after 4 min of pure O2 breathing the fractional N:! concentration in expired alveolar gas is down to less than 2oj,. NORMOVENTILATION : Normoventilation (F) ; Normoventilation (G). Normoventilation is characterized by an alveolar ventilation that produces an alveolar carbon dioxide pressure of about 40 torr at any metabolic rate. Syn. EUPNEA. NORMOXIA: Normoxie (F) ; Normoxie (G). A state in which the ambient oxygen pressure is approximately 150 rt 10 torr (i.e., the partial pressure of oxygen in air at sea level). OLIGOPNEA: OligopnCe (F); Oligopnoe (G). See HYPOPNEA. OXYGEN AFFINITY OF HEMOGLOBIN: Affinite de l’hemoglobine pour 1’oxygCne (F); Sauerstoffaffinitat des HZmoglobins (G). The oxygen affinity expresses the degree of oxygen saturation of blood or hemoglobin solutions at a defined oxygen pressure. The pH and temperature must be specified and, for most homeotherms, are 7.4 and body temperature. The oxygen affinity can be characterized by the OXYGEN HEMOGLOBIN EQUILIBRIUM CURVE. A widely used term characterizing the oxygen affinity is the oxygen pressure at half saturation of blood or hemoglobin, respectively. See OXYGEN HALF-SATURATION PRESSURE OF HEMOGLOBIN (PsO). OXYGEN CAPACITY: Capacite d’oxygsne (F) ; Sauerstoffkapazitat (G). The maximum amount of oxygen that can be made to combine chemically with the hemoglobin in a unit volume of blood. Ordinarily, it is expressed in ml 02 (STPD)/ 100 ml blood or mmole OJliter blood. Note that the oxygen capacity does not include physically dissolved oxygen. For mammalian blood at least 150 torr of oxygen pressure are necessary for 100% oxygen saturation of the hemoglobin. For male human blood the mean hemoglobin content is 15.3 corresponds to an oxygen capacity of g/100 ml blood, which 2 1 ml 02/l 00 ml blood. It follows that 1 g hemoglobin binds almost 1.389 ml 02, the value theoretically predictable. MYOGLOBIN : Myoglobine (F) ; Myoglobin (G) . A hemoproteid naturally occurring in muscle cells, consisting of one polypeptide chain to which a heme group is attached. The heme is made of four pyrrole rings and a divalent iron (Fe2fprotoporphyrin) which combines reversibly with molecular oxygen. Symb. Mb. OXYGEN-CARBON DIOXIDE CONCENTRATION DIAGRAM: Diagramme des concentrations Oz-CO2 (F) ; 02CO2 Konzentrationsdiagramm (G). Plot of CO2 concentration vs. 02 concentration, used almost exclusively for blood. 02 and CO2 concentrations in the arterial blood and in the venous blood may be simultaneously represented for various organs. The slope of the line joining an arterial and a venous point of an organ in the steady state indicates the respiratory quotient of that organ. NITROGEN narkose pressure at 7 Ata OXYGEN-CARBON DIOXIDE PRESSURE DIAGRAM: Diagramme des pressions partielles 02-CO? (F); OS-CO2 Druck-Diagramm (G). Plot of the CO2 partial pressure vs. the 02 partial pressure in biological media such as inspired NARCOSIS: Narcose a l’azote (F); Stickstoff(G). Depression of brain function due to high partial of nitrogen. In a deep dive, for example, air breathing may lead to a Nz narcosis. N2 narcosis may be avoided Downloaded from http://jap.physiology.org/ by 10.220.33.1 on June 15, 2017 METHEMOGLOBIN : Methemoglobine (F) ; Methamoglobin (G). Hemoglobin in which iron is in the ferric state. Because the iron is oxidized, methemoglobin is incapable of oxygen transport. Methemoglobins are formed by various drugs and occur under pathological conditions. Many methods for hemoglobin measurements utilize methemoglobin (chlorhemiglobin, cyanhemiglobin). Syn. Hemiglobin; ferrihemoglobin. ON GLOSSARY ON RESPIRATION AND GAS EXCHANGE gas or water, expired gas or water, alveolar gas, or arterial and venous blood. All representative points of the 02 and CO2 pressures throughout the body can be represented simultaneously on this diagram. Furthermore, since for a given fluid, 02 and CO2 concentrations are completely defined by the 02 and CO2 pressures, it is possible to draw on the Op-CO2 pressure diagram a family of 02 and CO2 isoconcentration lines, demonstrating simultaneously and quantitatively the Bohr and Haldane effects. Finally, gas exchange ratio lines in gas and in blood may be plotted on the diagram. Also called Fenn-Rahn-Otis diagram, Fenn diagram, or 02-CO2 diagram. OXYGEN CONCENTRATION : Concentration d’oxyg2ne (F) ; Sauerstoffkonzentration (G). The concentration of oxygen in a blood sample, including both oxygen combined with hemoglobin and physically dissolved oxygen, ordinarily expressed as ml 02 (STPD) /lOO ml blood, or mmole OJliter. Not recommended synonym: oxygen content. Symb. For arterial blood, Cao2. plotted on the ordinate may be given in ml 02/100 ml blood or in mmole On/liter blood or as a percent of the OXYGEN CAPACITY, i.e., the percent saturation. Note that sometimes the total amount of oxygen in the blood, both combined with hemoglobin and free in solution, is plotted. Abbr. OHEC. OXYGEN POISONING: Empoisonnement par l’oxygene (F) ; Sauerstoffvergiftung (G). Deleterious effects due to high partial pressures of oxygen. See OXYGEN TOXICITY. OXYGEN SATURATION: Saturation d’oxyghne (F) ; Sauerstoff-Sattigung (G). The amount of oxygen combined with hemoglobin, expressed as a percentage of the oxygen capacity of that hemoglobin. Symb. So2; in arterial blood, Sao,. OXYGEN STORES : R&erves d’oxyg&ne (F) ; Sauerstoffspeicher (G). Amount of 02 which is stored in the various compartments of the body: lung, arterial and venous blood, and tissues. Great amounts of oxygen are fixed in blood (as oxyhemoglobin) and muscles (as oxymyoglobin), 800 and 150 ml, respectively, for a 70-kg man. The alveolar gas contains a few hundred ml of oxygen. Some 50 ml are dissolved in the tissues. l Qo2* OXYGEN COST OF BREATHING: Gout energetique de la respiration (F) ; Sauerstoffverbrauch der Atemarbeit (G). The rate of consumption of oxygen required by the respiratory muscles to ventilate the lungs. OXYGEN DEBT: Dette d’oxygene (F) ; Sauerstoffschuld (G). During recovery from a period of exercise or of apnea, there is a volume of oxygen which is taken up by the lungs, which is in excess of the volume of oxygen necessary to meet the resting metabolism of the preexercise period. This is called the oxygen debt. It represents repayment of oxygen and energy stores which were depleted at a time when oxygen supply from the environment was inadequate to sustain aerobic metabolism, and the stores had to be called upon. OXYGEN DISSOCIATION CURVE OF HEMOGLOBIN: Courbe de dissociation de l’hemoglobine (F) ; Sauerstoffbindungskurve oder Sauerstoffdissoziationskurve des Hamoglobins (G). See OXYGEN HEMOGLOBIN EQUILIBRIUM CURVE. OXYGEN TOXICITY: T oxicit6 de l’oxyg2ne vergiftung (G). The poisonous quality of pressures, which tends to interfere with functions, causing loss of consciousness and example. (F); Sauerstoffoxygen at high various bodily convulsions, for OXYGEN UPTAKE : Pr&vement d’oxygene (F) ; Sauerstoffaufnahme (G). Amount of oxygen taken up by the body from the environment, by the blood from the alveolar gas, or by an organ or tissue from the blood. When this amount of oxygen is expressed per unit of time one deals with an “oxygen uptake rate.” “Oxygen consumption” refers more specifically to the oxygen uptake rate by all tissues of the body and is equal to the oxygen uptake rate of the organism only when the 02 stores are constant. Symb. Vo2. PANTING: Haletement (F) ; Hecheln (G). A pattern of ventilation characterized by high frequency and small tidal volume. Rapid and shallow breathing. Some animals, such as the dog and the cow, pant when exposed to heat; hence the terms thermal panting and tachypnea. During panting the flow rate of gas moved back and forth in the dead space of the upper airways is high. This process allows for evaporation of water, and hence of heat loss, with little or no increase of alveolar ventilation. PARTITION COEFFICIENT : Coefficient de partition (F) ; Trennungskoeffizient (G). The ratio at equilibrium between the concentration of a given gas in two or more solvents. OXYGEN HALF-SATURATION PRESSURE OF HEMOGLOBIN : Pression d’oxyg&e de demi-saturation (F) ; Sauerstoffhalbsattigungsdruck des Hamoglobins (G). Oxygen pressure necessary to saturate hemoglobin 50y0 with oxygen (at pH 7.4 or 40 torr CO2 pressure and body temperature). Widely used for quantification of oxygen affinity (see OXYGEN AFFINITY). Symb. P50. PERIODIC BREATHING : Respiration periodique (F) ; Periodische Atmung (G). Abnormal pattern of breathing in which groups of ventilatory cycles are separated by pauses, for example, in CHEYNE-STOKES BREATHING. OXYGEN HEMOGLOBIN EQUILIBRIUM CURVE. Courbe d’equilibre entre l’hemoglobine et l’oxyg&ne (F) ; SauerstoffHamoglobin Gleichgewichtskurve (G). Relation of the amount of oxygen chemically bound to hemoglobin as a function of the oxygen pressure in torr (pH or Pco:! and temperature should be stated). The amount of oxygen PHYSIOLOGICAL DEAD SPACE : Espace mort physiologique (F) ; Physiologischer Totraum (G). Calculated volume which accounts for the difference between the pressures of CO2 in expired and alveolar gas (or arterial blood). Physiological dead space reflects the combination of anatomical dead space and alveolar dead space, the volume of the latter Downloaded from http://jap.physiology.org/ by 10.220.33.1 on June 15, 2017 OXYGEN CONSUMPTION: Consommation d’oxygene (F) ; Sauerstoffverbrauch (G). Rate of oxygen uptake of organisms, tissues, or cells. Common units: ml 02 (STPD) /(kg min) or ml 02 (STPD) /(kg l hr). For whole organisms the oxygen consumption is commonly expressed per unit surface area or some power of the body weight. For tissue samples or isolated cells Qo2 = ~1 02/hr per mg dry weight. Symb. Vo2 or 555 556 GLOSSARY increasing ventilation with the /perfusion importance of the ratio in the lung. nonuniformity Abbr. VD. of the PL ,ASMA, SEPARATED : Plasma, &pare (F) ; Plasma, abgetrennt (G). Plasma separated from blood cells. ‘Separated” is specified to emphasize that, since the plasma is no longer associated with blood cells, the results of equilibration with various gas pressures will differ from those of plasma which has been separated from the blood after equilibration (which is termed TRUE PLASMA). Sometimes SEPARATED PL-4SMA is used for studies of acid-base balance, with varying CO2 pressures and measuree.g., equilibration ment of CO2 concentration. Its composition under new equilibration conditions cannot include any influence of red cell exchanges since they have been excluded. ON RESPIRATION AND GAS EXCHANGE PNEUMOGRAPH : Pneumographe (F) ; Pneumograph (G). Apparatus which records the movements of ventilation, for instance by an inflated coil around the thorax. The record itself is called a pneumogram. A pneumograph measures exactly the duration of the ventilatory cycle but generally does not reliably record the amplitude of the ventilatory movement. See SPIROGRAPH. PNEUMOTACHOGRAPH : Pneumotachographe (F) ; Pneumotachograph (G). A d evice for measuring instantaneous gas flow rates in breathing by recording the pressure drop across a fixed flow resistance of known pressure-flow characteristics, commonly connected to the airway by means of a mouthpiece, face mask, or cannula. The flow resistance usually consists either of parallel capillary tubes (Fleisch type) or of finemeshed screen (Silverman-Lilly type). PI JASMA, TRUE: Plasma, vrai (F) ; Plasma, wahres (G). Plasma separated anaerobically from whole blood. Its analysis reveals the composition it had while still in contact with the cells. Commonly used for studies of acid-base balance. PRESSURE : Pression pleurale (F) ; Pleuraldruck (G). PI ,EURAL Literally, the pressure between the visceral and parietal pleura relative to atmospheric pressure, in cm H20. Particular definition is necessary. In respiratory measurements pleural pressure is used to estimate transpulmonary pressure, i.e., the pressure difference between the airway opening and the pleural surface of the lung. Average local lung surface pressures are measured directly from small induced pneumothoraces, or indirectly from esophageal balloon catheters. Pressures in the pleural liquid as it exists normally in the pleural space depend on the equilibrium between capillary blood and pleural liquid colloid osmotic and hydrostatic pressures. Pleural liquid pressures may be negative with respect to average local surface pressures. This is possible because the lung surface is not solely exposed to pleural liquid; it is exposed also to solid contact with parietal pleura, which exerts the equivalent of positive pressures on the lung surface in compensation for differences between liquid and average surface pressures. Symb. Ppl. PNEUMOTHORAX The presence space. POLYPNEA: : Pneumothorax (F) ; Pneumothorax (G). of gas outside the lungs and within the pleural Polyp&e (F) ; Polypnoe (G). See TACHYPNEA. PULMONARY CAPACITIES: CapacitCs pulmonaires (F) ; Lungenkapazitaten (G). Denote lung volumes which are formed of two or more subvolumes. Functional residual capacity is the sum of residual volume and expiratory reserve volume. Inspiratory capacity is the sum of tidal volume and inspiratory reserve volume. Total lung capacity is the pulmonary volume at the end of maximal inspiration; it is formed by the sum of two capacities: functional residual capacity and inspiratory capacity, i.e., the sum of inspiratory reserve volume, tidal volume, expiratory reserve volume, and residual volume. REBREATHING: Rebreathing (F); Riickatmung (G). Ventilation of the lungs in a closed system, i.e., without renewal of inhaled gas. Rebreathing occurs only exceptionally in normal life. Experimentally it may be used to attempt to equilibrate alveolar gas and venous blood CO2 pressure and thus to determine the latter. RESISTANCE, FLOW: Resistance a 1’6coulement (F) ; Strijmungswiderstand (G). The ratio of the flow-resistive components of pressure to simultaneous flow, in cm HzO/liter per sec. Flow-resistive components of pressure are obtained by subtracting any elastic or inertial components, proportional respectively to volume and volume acceleration. Most flow resistances in the respiratory system are nonlinear, varying with the magnitude (see ROHRER’S CONSTANTS) and direction of flow, with lung volume and lung volume history, and possibly with volume acceleration. Accordingly, careful specification of the conditions of measurement is necessary. Note that flow resistance is not limited to gas flow; it also is used to describe tissue flow resistance. Symb. R. RESPIRATOR: device Respirateur used to produce (F) ; Respirator or assist pulmonary (G). A mechanical ventilation. Downloaded from http://jap.physiology.org/ by 10.220.33.1 on June 15, 2017 : Plethysmographe (F) ; Plethysmograph PI JE THYSMOGRAPH placed around a living structure for (G). A rigid c h amber the purpose of measuring changes in the volume of the structure. In respiratory measurements, the entire body is ordinarily enclosed (“body plethysmograph”) and the plethysmograph is used to measure changes in volume of gas in the system produced 1) by solution and volatilization (e.g., uptake of foreign gases into the blood), 2) by changes in pressure or temperature (e.g., gas compression in the lungs, expansion of gas upon passing into the warm, moist lungs), or 3) by breathing through a tube to the outside. Three types of plethysmograph are used: a) pressure, b) volume, and c) pressure-volume. In ty:pe a, the body chambers have fixed volumes and volume changes are measured in terms of pressure change secondary to gas compression (inside the chamber, outside the body). In tvpe b, the body chambers serve essentially as conduits between the body surface and devices (spirometers or integrating flowmeters) which measure gas displacements. Type c combines a and b by appropriate summing of chamber pressure and volume displacements. GLOSSZKY ON RESPIR.4TORY zentren activity cspiratory CENTERS: Centres respiratoires (G). Bilateral brainstem structures results in periodic alternation of activities. RESPI RESPIRATION AND EXCHANGE (F) ; Atmungswhose periodic inspiratory and R4TORY CYCLE : Cycle respiratoire (F) ; Atemzyklus (G). A respiratory cycle is constituted by the inspiration followed by the expiration of a given volume of gas, called tidal volume. The duration of the respiratory cycle is the respiratory or ventilatory period, whose reciprocal is the ventilatory frequency. RESPIR~4TORY QUOTIENT. EXCHANGE RESPIR4TORY Pitemfrequenz of time. Symb. FREQUENCY: (G). The number f. RESPI GAS RATIO : See RESPIRATORY Frequence of breathing respiratoire (F) ; cycles per unit RE SPIli.4’~~ORY QUOTIENT: Quotient respiratoire (F); Respiratorischer Quotient (G). Quotient of the volume of CO? produced divided by the volume of 02 consumed by an organism, an organ, or a tissue during a given period of time. Respiratory quotients are measured by comparing the composition of an incoming and an outgoing medium, e.g., inspired and expired gas, inspired gas and alveolar gas, or arterial and venous blood. Sometimes the phase “respiratory exchange ratio” is used to designate the ratio of CO2 output to the 02 uptake by the lungs, ‘?espiratory quotient” being restricted to the actual metabolic CO:! output and 02 uptake by the tissues. With this definition respiratory quotient and respiratory exchange ratio are identical in the steady state, a condition which implies constancy of the 02 and CO2 stores. ,4bbr. RQ or R. ROHRER’S CONSTANTS: Constantes de Rohrer (F); Rohrers Konstanten (G). Constants in an empirical expression for airway resistance, namely : R = K1 + K& where K1 is the flow-independent component and Kz the flow-dependent component of the resistance, R, and V is the instantaneous rate of flow. Rohrer’s original expression had a theoretical The expression nevertheless fits obbasis, since disproved. served flow-resistive pressure-flow relationships closely if applied over a small range of flows and excluding expiratory plateaus. Symb. K1 and Kz. ROOT EFFECT: Eflet Root (F) ; Root-Effekt (G). A property of many fish hemoglobins which is characterized by displacement of the oxygen hemoglobin equilibrium curve clown and to the right with increasing Hf concentration. This effect differs from the BOHR EFFECT in that, even at high oxygen pressures (sometimes up to several hundred .4ta), no complete oxygen saturation is accomplished. SHUNT: Shunt (F); K urzschluss (G). Vascular connection between circulatory pathways so that venous blood is diverted into vessels containing arterialized blood (right-to-left shunt, venous admixture) or vice versa (left-to-right shunt). Rightto-left shunt within the lung, heart, or large vessels due to malformations are more important in respiratory physiology. Flow from left to right through a shunt should be marked with a negative sign. SOLUBILITY COEFFICIENT FOR GASES: Coefficient de solubilite des gaz (F); Loslichkeitskoeffizient fur Gase (G). The ml gas physically dissolved (STPD) in 1 ml of fluid at 1 atmosphere test gas pressure, at a given temperature. For 02 in water at 37’ C; a = 0.0239 ml. For 02 in blood at 37O c; a = 0.0223 ml (15 g Hb). Symb. cy, e.g., cyo,,.I SPIROGRAPH device, collects volume TORY : Spirographe (F) ; Spirograph (G). Mechanical including bellows or other sealed, moving part, which and stores gases and provides a graphical record of changes. See BREATHING PATTERN, RESPIRACYCLE. SPIROMETER: similar Spirom&re to a spirograph (F) ; Spirometer (G). but without recording An apparatus facility. STANDARD BICARBONATE : Bicarbonate standard (F) ; Standardbikarbonatwert (G). Bicarbonate concentration in plasma (SEG PLASMA, TRUE) separated anaerobically from whole blood that has been saturated with oxygen and equilibrated at PCO~ = 40 torr at 37O C. A measure of the metabolic disturbance of acid-base balance in a sample of blood after any respiratory disturbance has been corrected. Normal value 2 l-26 mEq /liter. STPD CONDITIONS: Conditions STPD (F); STPD Bedingungen (G). Standard temperature and pressure, dry. These are the conditions of a volume of gas at 0’ C, at 760 torr, without water vapor. A STPD volume of a given gas contains a known number of moles of that gas. Abbr. STUD. SURFACTANT, PULMONARY: Surfactant pulmonaire (F) ; Oberflachenaktive Substanzen, Lunge (G). Phospholipid (mainly dipalmitoyl lecithin)-protein complex which lines alveoli (and possibly small airways) and accounts for the low surface tension which makes air space (and airway) patency possible at low transpulmonary pressures. TACHYPNEA breathing defined TIDAL : Tachypnee (F) ; Tachypnoe (G). Increased in comparison with breathing at rest (less exactly than and not to be confused with hyperventilation). VOLUME : Volume Volume of gas which ventilatory cycle. Symb. courant (F) ; Atemzugvolumen is inspirecl and expired during VT. (G). one TONOMETRY: Tonometrie (F); Tonometrie (G). A method for measuring gas pressures in fluids, by equilibrating a small gas bubble at known pressure and temperature with a relatively large volume of fluid, followed by analysis of the bubble. More recently it has come to be used (illogically and regrettably) to mean any equilibration of gas and liquid phases including situations in which the volume of gas is relatively large and the volume of liquid relatively small so that the gas phase determines the gas pressure in the liquid rather than vice versa. Downloaded from http://jap.physiology.org/ by 10.220.33.1 on June 15, 2017 R4TORY MUSCLES : Muscles respiratoires (F) ; Atemmuskeln (G). Those muscles whose actions produce the volume changes of the respiratory system during breathing. They include inspiratory muscles (mainly Diaphragm and External Intercostals, but also accessory muscles: Scaleni, Sternomastoids, Trapezius, Pectoralis Major, Pectoralis Minor, Subclavius, Latissimus Dorsi, Serratus Anterior, and others, including all muscles which extend the back), and espiratory muscles (mainly Internal Intercostals and Abdominals, and also all muscles which flex the back). 557 558 TORR: GLOSSARY Torr (F); Torr (G). A unit of pressure equal to 1,333.22 dynes/cm2 or 1.33322 millibars. The torr is equal to the pressure required to support a column of mercury 1 mm high when the mercury is of standard density and subjected to standard acceleration. These standard conditions are met at 0’ C and 45’ latitude, where the acceleration of gravity is a mercury barometer at other 980.6 cm/set 2. In reading temperatures and latitudes, corrections, which commonly exceed 2 torr, must be introduced for these terms and for the thermal expansion of the measuring scale used. The torr is synonymous with pressure unit, mm Hg. Symb. torr. TRANSPULMONARY PRESSURE : Pression transpulmonaire (F) ; Transpulmonaler Druck (G). Pressure difference between airway opening (mouth, nares, or cannula opening) and the visceral pleural surface, in cm H20. Transpulmonary in the sense used includes extrapulmonary structures, e.g., trachea and extrathoracic airways. This usage has come about for want of an anatomic term which includes all of the airways and the lungs together. Symb. PL. VENTILATION, ALVEOLAR : Ventilation alveolaire (F) ; Alveolare Ventilation (G). Physiological process by which alveolar gas is completely removed and replaced with fresh gas. ventilation is less than total ventilation because - Alveolar when a tidal volume of gas leaves the alveolar spaces, the AND GAS EXCHANGE last part does not get expelled from the body but occupies the dead space, to be reinspired with the next inspiration. Thus the volume of alveolar gas actually expelled completely is equal to the tidal volume minus the volume of the dead space. This truly complete expiration volume times the ventilatory frequency constitutes the alveolar ventilation. Symb. VA. VENTILATION/PERFUSION RATIO : Rapport ventilation perfusion (F) ; Ventilation-Durchblutungs Verhtiltnis (G). Ratio of the alveolar ventilation to the blood perfusion volume flow through the pulmonary parenchyma. This ratio is a fundamental determinant of the 02 and CO2 pressure of the alveolar gas and of the end-capillary blood. Throughout the lungs the local ventilation/perfusion ratios vary and consequently the local alveolar gas and end-capillary blood compositions also vary. Symb. VA/Q. VENTILATORY EQUIVALENT : Equivalent ventilatoire (F) ; Ventilationsaquivalent (G). Ratio of the ventilatory flow rate expressed in BTPS conditions to the oxygen uptake rate expressed in STPD conditions. This ratio indicates how many volumes BTPS of air are breathed to obtain one volume 02 STPD. In normal man a common figure is 28 liters (BTPS) breathed for 1 liter (STPD) 02 taken up. VITAL CAPACITY: CapacitC vitale (F) ; Vitalkapazitat (G). Volume measured on complete expiration after the deepest inspiration, but without respect to the effort involved. Abbr. VC. Inspiratory vital capacity is the maximal volume measured on inspiration after a full expiration. Abbr. IVC. Forced vital capacity is the volume of gas expired after full inspiration, and with expiration delivered as rapidly and completely as possible. Abbr. FVC. WORK OF BREATHING : Travail ventilatoire (F) ; Atemarbeit (G). The energy required for breathing movements. Usually estimated as s PdV from volume-pressure diagrams of the passively driven respiratory system or from volume-transpulmonary pressure diagrams during spontaneous breathing with additional work done on the chest wall approximated from separate measurements made during voluntary relaxation, commonly expressed as a rate of work, i.e., work per respiratory cycle times respiratory frequency. Work of inspiration (Symb. Winsp ) and work of expiration (Symb. We,& may be separately specified, and rate of work is symbolized, W. VALSALVA’S MANEUVER: Manoeuvre de Valsalva (F) ; Valsalva’scher Versuch (G). Expiratory effort with closed During this maneuver intrathoracic pressure is airway. raised, and venous return and cardiac output are diminished. VENTILATION: Ventilation (F) ; Ventilation (G). Physiological process by which gas is renewed in the lungs. The word ventilation sometimes designates ventilatory flow rate (or ventilatory minute volume) which is the product of the tidal volume by the ventilatory frequency. Ventilation is often referred to as “total ventilation” to distinguish it from “alveolar ventilation” (see VENTILATION, ALVEOLAR). RESPIRATION Downloaded from http://jap.physiology.org/ by 10.220.33.1 on June 15, 2017 TRANSTHORACIC PRESSURE : Pression transthoracique (F) ; Transthorakaler Druck (G). Pressure difference between parietal pleural surface and body surface. Transthoracic in the chest wall” (see CHEST the sense used means “across WALL). It is a misnomer which has come into use because of the lack of an adjectival term for chest wall. Symb. Pw. ON