scholarly journals The interplay of cutaneous water loss, gas exchange and blood flow in the toad, Bufo woodhousei: adaptations in a terrestrially adapted amphibian

2005 ◽  
Vol 208 (1) ◽  
pp. 105-112 ◽  
Author(s):  
W. W. Burggren
Keyword(s):  
Blood Flow ◽  
Gas Exchange ◽  
Water Loss ◽  
Bufo Woodhousei ◽  
Toad Bufo

Regulation of Blood Flow through Ventral Pelvic Skin by Environmental Water and NaCl in the Toad Bufo woodhousei

1992 ◽  
Vol 65 (3) ◽  
pp. 540-553 ◽  
Author(s):  
Gary M. Malvin ◽  
Laura Hood ◽  
Marlene Sanchez
Keyword(s):  
Blood Flow ◽  
Environmental Water ◽  
Flow Through ◽  
Bufo Woodhousei ◽  
Toad Bufo

Mechanisms of improvement in pulmonary gas exchange during isovolemic hemodilution

1999 ◽  
Vol 87 (1) ◽  
pp. 132-141 ◽  
Author(s):  
Steven Deem ◽  
Richard G. Hedges ◽  
Steven McKinney ◽  
Nayak L. Polissar ◽  
Michael K. Alberts ◽  
...  
Keyword(s):  
Blood Flow ◽  
Fractal Dimension ◽  
Gas Exchange ◽  
Spatial Correlation ◽  
Pulmonary Blood Flow ◽  
Minute Ventilation ◽  
Flow Distribution ◽  
Pulmonary Gas Exchange ◽  
Normal Lung ◽  
Blood Flow Distribution

Severe anemia is associated with remarkable stability of pulmonary gas exchange (S. Deem, M. K. Alberts, M. J. Bishop, A. Bidani, and E. R. Swenson. J. Appl. Physiol. 83: 240–246, 1997), although the factors that contribute to this stability have not been studied in detail. In the present study, 10 Flemish Giant rabbits were anesthetized, paralyzed, and mechanically ventilated at a fixed minute ventilation. Serial hemodilution was performed in five rabbits by simultaneous withdrawal of blood and infusion of an equal volume of 6% hetastarch; five rabbits were followed over a comparable time. Ventilation-perfusion (V˙a/Q˙) relationships were studied by using the multiple inert-gas-elimination technique, and pulmonary blood flow distribution was assessed by using fluorescent microspheres. Expired nitric oxide (NO) was measured by chemiluminescence. Hemodilution resulted in a linear fall in hematocrit over time, from 30 ± 1.6 to 11 ± 1%. Anemia was associated with an increase in arterial [Formula: see text] in comparison with controls ( P < 0.01 between groups). The improvement in O2 exchange was associated with reducedV˙a/Q˙heterogeneity, a reduction in the fractal dimension of pulmonary blood flow ( P = 0.04), and a relative increase in the spatial correlation of pulmonary blood flow ( P = 0.04). Expired NO increased with anemia, whereas it remained stable in control animals ( P < 0.0001 between groups). Anemia results in improved gas exchange in the normal lung as a result of an improvement in overallV˙a/Q˙matching. In turn, this may be a result of favorable changes in pulmonary blood flow distribution, as assessed by the fractal dimension and spatial correlation of blood flow and as a result of increased NO availability.

Observations on Body Temperature and Activity in the Toad Bufo woodhousei fowleri

Copeia ◽  
1966 ◽  
Vol 1966 (3) ◽  
pp. 581 ◽  
Author(s):  
Sydney Hadfield
Keyword(s):  
Body Temperature ◽  
Bufo Woodhousei ◽  
Toad Bufo

Cutaneous gas exchange and low evaporative water loss in the frogsPhyllomedusa sauvagei andChiromantis xerampelina

1987 ◽  
Vol 157 (4) ◽  
pp. 423-427 ◽  
Author(s):  
Jerry N. Stinner ◽  
Vaughan H. Shoemaker
Keyword(s):  
Gas Exchange ◽  
Water Loss ◽  
Evaporative Water Loss ◽  
Evaporative Water

scholarly journals Gas exchange characteristics, metabolic rate and water loss of the Heelwalker, Karoophasma biedouwensis (Mantophasmatodea: Austrophasmatidae)

2006 ◽  
Vol 52 (5) ◽  
pp. 442-449 ◽  
Author(s):  
S.L. Chown ◽  
E. Marais ◽  
M.D. Picker ◽  
J.S. Terblanche
Keyword(s):  
Gas Exchange ◽  
Metabolic Rate ◽  
Water Loss ◽  
Gas Exchange Characteristics

Emergence of matched airway and vascular trees from fractal rules

2011 ◽  
Vol 110 (4) ◽  
pp. 1119-1129 ◽  
Author(s):  
Robb W. Glenny
Keyword(s):  
Blood Flow ◽  
Gas Exchange ◽  
Mathematical Models ◽  
Fetal Development ◽  
Fractal Geometry ◽  
Branching Morphogenesis ◽  
Emergent Behavior ◽  
Complex Structures ◽  
Airway Trees ◽  
Vascular Trees

The bronchial, arterial, and venous trees of the lung are complex interwoven structures. Their geometries are created during fetal development through common processes of branching morphogenesis. Insights from fractal geometry suggest that these extensively arborizing trees may be created through simple recursive rules. Mathematical models of Turing have demonstrated how only a few proteins could interact to direct this branching morphogenesis. Development of the airway and vascular trees could, therefore, be considered an example of emergent behavior as complex structures are created from the interaction of only a few processes. However, unlike inanimate emergent structures, the geometries of the airway and vascular trees are highly stereotyped. This review will integrate the concepts of emergence, fractals, and evolution to demonstrate how the complex branching geometries of the airway and vascular trees are ideally suited for gas exchange in the lung. The review will also speculate on how the heterogeneity of blood flow and ventilation created by the vascular and airway trees is overcome through their coordinated construction during fetal development.

Effects of Vaporized Perfluorocarbon on Pulmonary Blood Flow and Ventilation/Perfusion Distribution in a Model of Acute Respiratory Distress Syndrome

2001 ◽  
Vol 95 (6) ◽  
pp. 1414-1421 ◽  
Author(s):  
Matthias Hübler ◽  
Jennifer E. Souders ◽  
Erin D. Shade ◽  
Nayak L. Polissar ◽  
Carmel Schimmel ◽  
...  
Keyword(s):  
Blood Flow ◽  
Oleic Acid ◽  
Gas Exchange ◽  
Lung Injury ◽  
Repeated Measures ◽  
Pulmonary Blood Flow ◽  
Analysis Of Covariance ◽  
Inert Gas ◽  
Low Flow ◽  
Repeated Measures Analysis

Background Perfluorocarbon (PFC) liquids are known to improve gas exchange and pulmonary function in various models of acute respiratory failure. Vaporization has been recently reported as a new method of delivering PFC to the lung. Our aim was to study the effect of PFC vapor on the ventilation/perfusion (VA/Q) matching and relative pulmonary blood flow (Qrel) distribution. Methods In nine sheep, lung injury was induced using oleic acid. Four sheep were treated with vaporized perfluorohexane (PFX) for 30 min, whereas the remaining sheep served as control animals. Vaporization was achieved using a modified isoflurane vaporizer. The animals were studied for 90 min after vaporization. VA/Q distributions were estimated using the multiple inert gas elimination technique. Change in Qrel distribution was assessed using fluorescent-labeled microspheres. Results Treatment with PFX vapor improved oxygenation significantly and led to significantly lower shunt values (P &lt; 0.05, repeated-measures analysis of covariance). Analysis of the multiple inert gas elimination technique data showed that animals treated with PFX vapor demonstrated a higher VA/Q heterogeneity than the control animals (P &lt; 0.05, repeated-measures analysis of covariance). Microsphere data showed a redistribution of Qrel attributable to oleic acid injury. Qrel shifted from areas that were initially high-flow to areas that were initially low-flow, with no difference in redistribution between the groups. After established injury, Qrel was redistributed to the nondependent lung areas in control animals, whereas Qrel distribution did not change in treatment animals. Conclusion In oleic acid lung injury, treatment with PFX vapor improves gas exchange by increasing VA/Q heterogeneity in the whole lung without a significant change in gravitational gradient.

Gas exchange in dogs in the prone and supine positions

1992 ◽  
Vol 72 (6) ◽  
pp. 2292-2297 ◽  
Author(s):  
K. C. Beck ◽  
J. Vettermann ◽  
K. Rehder
Keyword(s):  
Blood Flow ◽  
Gas Exchange ◽  
Prone Position ◽  
Pulmonary Blood Flow ◽  
Random Order ◽  
Arterial Pco2 ◽  
Supine Posture ◽  
Pulmonary Shunting ◽  
The Difference ◽  
Arterial Po2

To determine the cause of the difference in gas exchange between the prone and supine postures in dogs, gas exchange was assessed by the multiple inert gas elimination technique (MIGET) and distribution of pulmonary blood flow was determined using radioactively labeled microspheres in seven anesthetized paralyzed dogs. Each animal was studied in the prone and supine positions in random order while tidal volume and respiratory frequency were kept constant with mechanical ventilation. Mean arterial PO2 was significantly lower (P less than 0.01) in the supine [96 +/- 10 (SD) Torr] than in the prone (107 +/- 6 Torr) position, whereas arterial PCO2 was constant (38 Torr). The distribution of blood flow (Q) vs. ventilation-to-perfusion ratio obtained from MIGET was significantly wider (P less than 0.01) in the supine [ln SD(Q) = 0.75 +/- 0.26] than in the prone position [ln SD (Q) = 0.34 +/- 0.05]. Right-to-left pulmonary shunting was not significantly altered. The distribution of microspheres was more heterogeneous in the supine than in the prone position. The larger heterogeneity was due in part to dorsal-to-ventral gradients in Q in the supine position that were not present in the prone position (P less than 0.01). The decreased efficiency of oxygenation in the supine posture is caused by an increased ventilation-to-perfusion mismatch that accompanies an increase in the heterogeneity of Q distribution.

Ventilation/blood flow and gas exchange

Tubercle ◽  
1971 ◽  
Vol 52 (2) ◽  
pp. 154
Keyword(s):  
Blood Flow ◽  
Gas Exchange

scholarly journals Chronicvs.Short-Term Acute O3Exposure Effects on Nocturnal Transpiration in Two Californian Oaks

2007 ◽  
Vol 7 ◽  
pp. 134-140 ◽  
Author(s):  
N. E. Grulke ◽  
E. Paoletti ◽  
R. L. Heath
Keyword(s):  
Gas Exchange ◽  
Water Loss ◽  
Exchange System ◽  
Short Term ◽  
Blue Oak ◽  
Unexposed Control ◽  
Nocturnal Transpiration ◽  
Gas Exchange System ◽  
Black Oak ◽  
Oak Seedlings

We tested the effect of daytime chronic moderate ozone (O3) exposure, short-term acute exposure, and both chronic and acute O3exposure combined on nocturnal transpiration in California black oak and blue oak seedlings. Chronic O3exposure (70 ppb for 8 h/day) was implemented in open-top chambers for either 1 month (California black oak) or 2 months (blue oak). Acute O3exposure (~1 h in duration during the day, 120–220 ppb) was implemented in a novel gas exchange system that supplied and maintained known O3concentrations to a leaf cuvette. When exposed to chronic daytime O3exposure, both oaks exhibited increased nocturnal transpiration (without concurrent O3exposure) relative to unexposed control leaves (1.8× and 1.6×, black and blue oak, respectively). Short-term acute and chronic O3exposure did not further increase nocturnal transpiration in either species. In blue oak previously unexposed to O3, short-term acute O3exposure significantly enhanced nocturnal transpiration (2.0×) relative to leaves unexposed to O3. California black oak was unresponsive to (only) short-term acute O3exposure. Daytime chronic and/or acute O3exposures can increase foliar water loss at night in deciduous oak seedlings.

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