Branchial water- and blood-flow patterns and the structure of the gill of the crayfish Procambarus clarkii

1974 ◽  
Vol 52 (12) ◽  
pp. 1511-1518 ◽  
Author(s):  
W. W. Burggren ◽  
B. R. McMahon ◽  
J. W. Costerton
Keyword(s):  
Blood Flow ◽  
Fine Structure ◽  
Gas Exchange ◽  
Procambarus Clarkii ◽  
Gill Filament ◽  
Morphological Evidence ◽  
Gill Epithelium ◽  
Diffusion Distance ◽  
Gill Filaments ◽  
Blood Flow Patterns

Water flow within the branchial chamber, blood flow within the gill filaments, and the fine structure of the gill epithelium have been determined in the crayfish Procambarus clarkii. The epithelium of the podobranch filaments, which is 3.15–8.70 μ thick, represents the blood-to-water diffusion distance. Blood flow within the filament is arranged in a bidirectional system that is first cocurrent and then countercurrent to the flow of water irrigating the gills. Morphological evidence suggests that gas exchange might occur in both directions. Shunting of blood occurs within the gill filament and its significance in countercurrent blood flow and gas exchange is discussed.

Inhibition of thrombocyte aggregation during extracorporeal lung assist: a case report

Perfusion ◽  
2007 ◽  
Vol 22 (4) ◽  
pp. 293-297 ◽  
Author(s):  
Alois Philipp ◽  
Thomas Müller ◽  
Thomas Bein ◽  
Maik Foltan ◽  
Franz-Xaver Schmid ◽  
...  
Keyword(s):  
Blood Flow ◽  
Case Report ◽  
Gas Exchange ◽  
Acetylsalicylic Acid ◽  
Diffusion Distance ◽  
Thrombocyte Aggregation ◽  
Extracorporeal Lung Assist ◽  
End Products ◽  
Membrane Oxygenators ◽  
And Diffusion

Disclaimer: All authors declare that there are no beneficial arrangements with NovaLung® GmbH, Hechingen, Germany In extracorporeal lung assist, membrane oxygenators are used to improve gas exchange. Accumulations on the membranes of coagulation end products can increase resistance to blood flow and diffusion distance. Thus, functioning of the system can be impaired and, in extreme cases, lead to malfunction which may necessitate change out of the oxygenator. We describe a method that complements conventional continuous heparinisation with the administration of acetylsalicylic acid to inhibit thrombocyte aggregation. Perfusion (2007) 22, 293—298.

scholarly journals The fine structure of a rectifying electrotonic synapse.

1978 ◽  
Vol 79 (3) ◽  
pp. 764-773 ◽  
Author(s):  
R B Hanna ◽  
J S Keeter ◽  
G D Pappas
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Ventral Nerve Cord ◽  
Procambarus Clarkii ◽  
Giant Axon ◽  
Morphological Evidence ◽  
Giant Fiber ◽  
Ordered Array ◽  
20 Nm ◽  
Tubular Endoplasmic Reticulum

The synapses between the lateral giant axon and the giant motor axon found in the abdominal ganglia of the ventral nerve cord of the crayfish Procambarus clarkii are electronic. The junctional membrane rectifies, favoring impulse transmission from lateral giant fiber to giant motor fiber. This rectifying electronic junction consists of closely apposed membranes indistinguishable from ordinary arthropod gap junctions. The apposed membranes contain intramembrane particles that are approximately 12.5 nm in width. These particles have a central depression and are arranged in a loosely ordered array with a center-to-center spacing of about 20 nm. The only obvious morphological evidence of asymmetry is the presence of vesicles (about 80 nm in diameter) in the cytoplasm adjacent to the junctional region of the presynaptic lateral giant fiber. Vesicles are not present in the adjacent cytoplasm of the postsynaptic giant motor fiber; however, mitochondria and smooth tubular endoplasmic reticulum are more frequent in the cytoplasm of the giant motor fiber.

Control of gill filament blood flow by serotonin in the rainbow trout, Oncorhynchus mykiss

1995 ◽  
Vol 268 (5) ◽  
pp. R1224-R1229 ◽  
Author(s):  
L. Sundin ◽  
G. E. Nilsson ◽  
M. Block ◽  
C. O. Lofman
Keyword(s):  
Blood Flow ◽  
Water Immersion ◽  
Gill Filament ◽  
Video Camera ◽  
Distal Portion ◽  
Celiac Artery ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Concomitant Reduction ◽  
Gill Filaments ◽  
Serotonergic Receptor

The effects of exogenously applied serotonin [5-hydroxytryptamine (5-HT)] on the distal arterial vasculature of gill filaments were observed using an epi-illumination microscope equipped with a water-immersion objective and connected to a video camera. In addition, ventral aortic flow (Q) and celiac artery pressure (PCA) were measured. Intra-arterial injection of serotonin (100 nmol/kg) completely stopped the blood flow in the distal part of the filaments and caused a rapid decrease of PCA. Repeatedly, the flow reduction was found to coincide with a constriction of the distal portion of the efferent filamental vasculature. Because there was no concomitant reduction in Q, it is concluded that a redistribution of blood to more proximal parts of the filaments occurred. After treatment with the serotonergic receptor antagonist methysergide, the vasoconstrictor effect of serotonin on the filamental vasculature was eliminated, while a decrease in PCA was still observed. The results demonstrate a specific site(s) for the serotonergic vasoconstriction in the distal portion of the filament.

Regional Blood Flow Patterns along the Length of the Rodent Cochlea

1987 ◽  
Vol 103 (5) ◽  
pp. 176-181 ◽  
Author(s):  
Norma Slepecky ◽  
Clarence Angelborg ◽  
Hans-Christian Larsen
Keyword(s):  
Blood Flow ◽  
Regional Blood Flow ◽  
Flow Patterns ◽  
Blood Flow Patterns

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.

scholarly journals Fast and easy visualization of blood flow patterns in 4D Qflow MRI

2012 ◽  
Vol 14 (Suppl 1) ◽  
pp. W46
Author(s):  
Vikas Sinha ◽  
Gilion Hautvast ◽  
Jeroen Sonnemans ◽  
Hubrecht de Bliek ◽  
Andrei Jalba ◽  
...  
Keyword(s):  
Blood Flow ◽  
Flow Patterns ◽  
Blood Flow Patterns

Preservation of sickle cell blood-flow patterns during MR imaging: an in vivo study

1988 ◽  
Vol 151 (1) ◽  
pp. 139-141 ◽  
Author(s):  
AS Brody ◽  
SH Embury ◽  
WC Mentzer ◽  
ML Winkler ◽  
CA Gooding
Keyword(s):  
Blood Flow ◽  
Mr Imaging ◽  
Sickle Cell ◽  
Flow Patterns ◽  
In Vivo Study ◽  
Blood Flow Patterns
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