Gas exchange

2017 ◽  
Author(s):  
Derek Burton ◽  
Margaret Burton
Keyword(s):  
Carbon Dioxide ◽  
Gas Exchange ◽  
Water Flow ◽  
Carrying Capacity ◽  
Respiratory Rhythm ◽  
High Water ◽  
Oxygen Intake ◽  
Swim Bladder ◽  
Water Flows ◽  
Respiratory Centre

Oxygen intake for respiration, also carbon dioxide and, generally, ammonia elimination takes place across gas-exchange surfaces, usually the gills in fish. Water flows across gills, separated by the pharyngeal gill clefts, and supported by gill arches, and which possess highly folded surfaces covered by a very thin epithelium. Blood flow and water flow are separated only by the epithelium with a ‘countercurrent’ gas exchange between the two. A respiratory centre in the hind-brain is a respiratory rhythm pacemaker for the oral and pharyngeal ventilation movements creating water flow across the gills, although ‘ram ventilation’ occurs without such movements. The oxygen and carbon dioxide-carrying capacity of blood is increased considerably by temporary attachment to haemoglobin pigment in the erythrocytes. Some fish are air breathing, using lungs, swim bladder, skin or lips for gaseous exchange. Hypoxia, hypercapnia, supersaturation and high water temperatures present problems for fish respiration, which are discussed.

THE EFFECT OF ASPHYXIATION UNDER VARIOUS TENSIONS OF CARBON DIOXIDE ON THE SWIM BLADDER GASES OF SOME FRESHWATER FISH

1942 ◽  
Vol 20d (7) ◽  
pp. 209-219 ◽  
Author(s):  
Virginia Safford Black
Keyword(s):  
Carbon Dioxide ◽  
Gas Exchange ◽  
Freshwater Fish ◽  
Bladder Wall ◽  
Swim Bladder ◽  
Vascular Networks ◽  
Pumpkin Seed ◽  
Dissolved Carbon ◽  
Dissolved Carbon Dioxide ◽  
Water Saturated

Freshwater physostomous fish, possessing open swim bladders (dace, sucker, chub, bullhead, trout), and physoclistous fish, having closed swim bladders (perch, bass, pumpkin-seed, stickleback), were sealed in bottles of water saturated with air and containing various amounts of dissolved carbon dioxide. After asphyxiation, an analysis of the swim bladder gases showed that the swim bladder had gained some carbon dioxide and lost some oxygen. Fish with closed swim bladders possessing retia mirabilia and ovals, vascular networks that facilitate gas exchange, show a markedly greater exchange of gases during the experiments than fish with open swim bladders which have no intensely vascular regions on the swim bladder wall. The oxygen that leaves the swim bladder during asphyxiation is probably of no significant value to the fish for respiration.

Estimation of the virtual water trade between two Spanish regions: Castilla-la Mancha and Murcia

2010 ◽  
Vol 10 (5) ◽  
pp. 831-840 ◽  
Author(s):  
Ángel De Miguel ◽  
Eloy García ◽  
Irene De Buestamante
Keyword(s):  
Water Flow ◽  
Food Processing ◽  
Virtual Water ◽  
Water Transfer ◽  
Water Efficiency ◽  
International Context ◽  
Water Flows ◽  
Spanish Regions ◽  
La Mancha ◽  
Virtual Water Flow

Virtual water is defined as the water needed to produce a product. We can use virtual water flow calculations to estimate the water efficiency of a country, as well as its economic dependence on water resources. Former studies on this area have focused on quantifying the virtual water flows between countries, in an international context. In this study we reduce the action framework to regions within a country, determining the virtual water balance between two Spanish regions: Castilla-La Mancha and Murcia. In 2004, Castilla-La Mancha exported to Murcia 2,453,442 tons of commercial products, from which 1,191,628 tons were agricultural goods. In terms of virtual water, it means 1,365 hm3, including food-processing, and industrial products. It is necessary to add 350 hm3 to the result, because of the water transfer (Tajo-Segura transfer) between the rivers basins of these regions, so the final virtual water number, in 2004, was 1,715 hm3. The other way round, Murcia exported in 2004 2,069,000 tons of products, from which 490,351 tons were agricultural goods. That supposes 712 hm3 of virtual water. Virtual water flow is unbalanced and displaced towards Murcia with a difference of 1,003 hm3.

Modelling biofilm growth in the presence of carbon dioxide and water flow in the subsurface

2010 ◽  
Vol 33 (7) ◽  
pp. 762-781 ◽  
Author(s):  
Anozie Ebigbo ◽  
Rainer Helmig ◽  
Alfred B. Cunningham ◽  
Holger Class ◽  
Robin Gerlach
Keyword(s):  
Carbon Dioxide ◽  
Water Flow ◽  
Biofilm Growth

Eddy covariance flux measurements of momentum, heat and carbon dioxide in Hudson Bay at the onset of sea ice melt 

2021 ◽  
Author(s):  
Richard Sims ◽  
Brian Butterworth ◽  
Tim Papakyriakou ◽  
Mohamed Ahmed ◽  
Brent Else
Keyword(s):  
Carbon Dioxide ◽  
Gas Exchange ◽  
Sea Ice ◽  
Eddy Covariance ◽  
Open Water ◽  
The Arctic ◽  
Gas Transfer ◽  
Hudson Bay ◽  
Flux Measurements ◽  
Ice Fraction

<p>Remoteness and tough conditions have made the Arctic Ocean historically difficult to access; until recently this has resulted in an undersampling of trace gas and gas exchange measurements. The seasonal cycle of sea ice completely transforms the air sea interface and the dynamics of gas exchange. To make estimates of gas exchange in the presence of sea ice, sea ice fraction is frequently used to scale open water gas transfer parametrisations. It remains unclear whether this scaling is appropriate for all sea ice regions. Ship based eddy covariance measurements were made in Hudson Bay during the summer of 2018 from the icebreaker CCGS Amundsen. We will present fluxes of carbon dioxide (CO<sub>2</sub>), heat and momentum and will show how they change around the Hudson Bay polynya under varying sea ice conditions. We will explore how these fluxes change with wind speed and sea ice fraction. As freshwater stratification was encountered during the cruise, we will compare our measurements with other recent eddy covariance flux measurements made from icebreakers and also will compare our turbulent CO<sub>2 </sub>fluxes with bulk fluxes calculated using underway and surface bottle pCO<sub>2</sub> data. </p><p> </p>

Respiration in man during metabolic alkalosis

1962 ◽  
Vol 17 (1) ◽  
pp. 33-37 ◽  
Author(s):  
Daniel J. Stone
Keyword(s):  
Carbon Dioxide ◽  
Steady State ◽  
Lung Function ◽  
Gas Exchange ◽  
Metabolic Alkalosis ◽  
Time Lag ◽  
Respiratory Compensation ◽  
Arterial Ph ◽  
Oral Sodium ◽  
Ventilation Response

A steady state metabolic alkalosis was induced in two subjects over a period of several days utilizing oral sodium bicarbonate in dosages of 50 g/day. The purpose of inducing steady state metabolic alkalosis was to study the effects of such a state on the respiratory center responses to inspired gas mixtures, containing carbon dioxide, and to contrast these results with the control studies. The experiment was so designed that the arterial pH in both subjects tended to return toward normal in the presence of significant increases in blood bicarbonate. Repeated study of ventilation responses with room air and 4% and 6% carbon dioxide in inspired air revealed a definite and significant decrease in ventilation response to carbon dioxide during the periods of steady state alkalosis as compared to the control periods. Normal responses returned after some time lag. A consistent rise in paCOCO2 occurred with alkalosis, thus demonstrating respiratory compensation. In neither subject was total lung function or gas exchange affected by the alkalosis. The experiment was confirmed on several occasions with reproducible results. Note: (With the Research Assistance of Mary Di Lieto) Submitted on May 22, 1961

Inspiratory Speech as a Management Option for Spastic Dysphonia

1992 ◽  
Vol 101 (5) ◽  
pp. 375-382 ◽  
Author(s):  
Gordon A. Harrison ◽  
Richard H. Troughear ◽  
Pamela J. Davis ◽  
Alison L. Winkworth
Keyword(s):  
Carbon Dioxide ◽  
Gas Exchange ◽  
Voice Quality ◽  
Management Option ◽  
Communication Problems ◽  
Partial Pressures ◽  
The Subject ◽  
And Control ◽  
Laryngeal Resistance

A case study is reported of a subject who has used inspiratory speech (IS) for 6 years as a means of overcoming the communication problems of long-standing adductor spastic dysphonia (ASD). The subject was studied to confirm his use of IS, determine the mechanisms of its production, investigate its effects on ventilatory gas exchange, and confirm that it was perceptually preferable to ASD expiratory speech (ES). Results showed that the production and control of a high laryngeal resistance to airflow were necessary for usable IS. Voice quality was quantitatively and perceptually poor; however, the improved fluency and absence of phonatory spasm made IS the preferred speaking mode for both the listener and the speaker. Transcutaneous measurements of the partial pressures of oxygen and carbon dioxide in the subject's blood were made during extended speaking periods. These measurements indicated that ventilation was unchanged during IS, and that ventilation during ES was similar to the “hyperventilation” state of normal speakers. The reasons for the absence of phonatory spasm during IS are discussed, and the possibility of its use as a noninvasive management option for other ASD sufferers is addressed.

Cardiac output determination via reduced gas exchange of carbon dioxide within an existing ventilator

2001 ◽  
Vol 18 (Supplement 22) ◽  
pp. 35
Author(s):  
I. R. A. M. ◽  
M. zur Borg ◽  
H. van der Zee ◽  
G. van Dijk ◽  
J. Klein
Keyword(s):  
Carbon Dioxide ◽  
Cardiac Output ◽  
Gas Exchange ◽  
Cardiac Output Determination

scholarly journals Second-generation laryngeal mask airway as an alternative to endotracheal tube during prolonged laparoscopic abdominal surgery: a comparative analysis of intraoperative gas exchanges

2021 ◽  
Author(s):  
S Park ◽  
JE Lee ◽  
GS Choi ◽  
JM Kim ◽  
JS Ko ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Gas Exchange ◽  
Laryngeal Mask Airway ◽  
Abdominal Surgery ◽  
Partial Pressure ◽  
Endotracheal Tube ◽  
Second Generation ◽  
Laryngeal Mask ◽  
Arterial Partial Pressure ◽  
Prolonged Surgery

Introduction: Despite several advantages over endotracheal tube (ETT), laryngeal mask airway (LMA), which is used in emergencies under difficult airway maintenance conditions, is rarely utilized in prolonged surgery. We compared the variables representing intraoperative gas exchange with second-generation LMA and ETT during prolonged laparoscopic abdominal surgery. Methods: Prolonged surgery was defined as a surgery lasting more than 2 h. In total, 394 patients who underwent laparoscopic liver resection via either second-generation LMA or ETT were retrospectively analysed. Parameters including end-tidal pressure of carbon dioxide (ETCO2), tidal volume (TV), respiratory rate (RR), peak inspiratory pressure (PIP), arterial partial pressure of carbon dioxide (PaCO2), pH, and ratio of arterial partial pressure of oxygen to fractional inspired oxygen (PFR) during surgery were compared between the two groups. In addition, the incidence of postoperative pulmonary complications (PPC) including pulmonary aspiration was also compared. Results: The values of ETCO2, TV, RR and PIP during pneumoperitoneum were comparable between the two groups. Although PaCO2 at 2 h after induction was higher in patients with LMA (40.5 vs. 38.5 mmHg, p < 0.001), the pH and PFR values of the two groups were comparable. The incidence of PPC was not different. Conclusion: During prolonged laparoscopic abdominal surgery, the second-generation LMA facilitates adequate intraoperative gas exchange and represents an alternative to ETT.

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