Blood oxygen transport and metabolism of the confined lugworm Arenicola marina (L.)

1975 ◽  
Vol 63 (3) ◽  
pp. 647-660
Author(s):  
A. Toulmond
Keyword(s):  
Anaerobic Metabolism ◽  
Sea Water ◽  
Blood Oxygen ◽  
Total Blood ◽  
Oxygen Saturation Level ◽  
Gas Exchanges ◽  
Water Oxygen ◽  
Buffer Power ◽  
Flow Through ◽  
Total Blood Flow

Oxygen consumption (MO2), haemoglobin oxygen saturation level (SVO2) and pH (pHv) in prebranchial blood were measured in lugworms experimentally confined in sea water at 15 degrees C. Total blood flow through the gills (Vb) was estimated. For sea water oxygen partial pressure (PwO2) between 120 and 150 Torr MO2, SVO2 and Vb were high and nearly constant. For PwO2 less than 120 Torr, Vb fell quickly, MO2 progressively dropped, and metabolism remained aerobic at the expense of the prebrancial blood oxygen store. For PwO2 less than 50 Torr, Vb and SvO2 values were extremely low, and the low pHv and the modified buffer power of the surrounding sea water showed that anaerobic metabolism was occurring. Changes in respiratory gas exchanges and metabolism during the tidal cycle are deduced from the comparison of these results with data obtained in the field.

Differential Blood Flow Through the Afferent Branchial Arteries of the Skate, Raja Rhina

1970 ◽  
Vol 52 (3) ◽  
pp. 721-726 ◽  
Author(s):  
G. H. SATCHELL ◽  
D. HANSON ◽  
K. JOHANSEN
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Water Flow ◽  
Water Current ◽  
Total Blood ◽  
Flow Past ◽  
Flow Through ◽  
Branchial Arteries ◽  
Total Blood Flow ◽  
Raja Rhina

1. In Raja rhina the entire cardiac output is distributed to the afferent branchial arteries by two stem arteries on each side. In each of nine skates (1.5 to 7.5 kg.) the total blood flow to gills on one side was measured simultaneously by means of two electromagnetic flow probes implanted on the stem arteries. 2. At rest the average cardiac output was about 21 ml/kg. min. and blood flow was distributed almost equally to the anterior and posterior stem arteries. 3. During short periods of free swimming the proportion of blood flow through the posterior stem invariably increased. This increase is apparently correlated with increased water flow past these gills during swimming. 4. It is postulated that the selective change of blood flow with short exercise is caused by a decrease of vascular resistance of the posterior gills. 5. The data are discussed in relation to the bottom-living habits of skates and the alternate pathways of the respiratory water current through the spiracles at rest and through the mouth and spiracles during swimming. Comparisons are made with other elasmobranchs in regard to the configuration of the branchial vessels in relation to probable patterns of water flow past their gills.

Diving Ability of the Platypus

1994 ◽  
Vol 42 (1) ◽  
pp. 17 ◽  
Author(s):  
BK Evans ◽  
DR Jones ◽  
J Baldwin ◽  
GRJ Gabbott
Keyword(s):  
Heart Rate ◽  
Consumption Rate ◽  
Anaerobic Metabolism ◽  
Haemoglobin Concentration ◽  
Total Blood ◽  
Physiological Capacity ◽  
Oxygen Stores ◽  
Recovery Times ◽  
Oxygen Carrying Capacity ◽  
Ldh Isozymes

Reports of the underwater endurance of the platypus differ. In the present study, most dives observed at Melbourne Zoo were less than 3 min, but several were longer (up to 11 min). Calculated dive: surface ratios were between 2.5:1 and 20:1. Most dives in the laboratory were between 30 s and 4 min duration, and heart rate fell in all dives, from pre-dive rates of 140-230 to 10-120 beats min-1. These falls in heart rate indicate that blood supply to many tissues is restricted, but the short recovery times after dives suggest there is little anaerobic metabolism. Similarly, the distribution and properties of LDH isozymes in skeletal muscle do not suggest heavy dependence on anaerobic glycolysis, and the ability of platypus muscles to 'buffer' metabolic acids that accumulate during anaerobiosis is low relative to other diving mammals. The platypus dives after a large inspiration (about 50 mL for a 1-kg animal). Total blood volume of the platypus is not known, but haematocrit, haemoglobin concentration and oxygen-carrying capacity have been shown to be high. Myoglobin oxygen stores in platypus are about 5 mL per kg body weight. Estimates of available oxygen stores and oxygen consumption rate indicate little need for anaerobic metabolism during normal dives, and it is suggested that the platypus has the physiological capacity for greater underwater endurance than previously suggested.

USE OF TELECOMMUNICATIONS TO REDUCE THE IMPACT OF THE COVID-19 PANDEMIC

2021 ◽  
Vol 2 (1) ◽  
pp. 38-43
Author(s):  
Abdullajon Komilov ◽  
◽  
Madinabonu Sultonova ◽  
Durdona Orifjonova
Keyword(s):  
Oxygen Saturation ◽  
Chronic Diseases ◽  
Direct Contact ◽  
Healthcare Professionals ◽  
Automatic Monitoring ◽  
Saturation Level ◽  
Blood Oxygen ◽  
Blood Oxygen Saturation ◽  
Oxygen Saturation Level ◽  
The Impact

Today, the COVID-19 pandemic is one of the most pressing problems facing humanity. Therefore, reducing the population's level of infection with this virus is one of our government's main tasks.Therefore, it is necessary to isolate patients with chronic diseases as much as possible. Clients are more likely to be infected with caronavirus due to their age and the presence of underlying medical conditions.Limiting direct contact between such patients and observing healthcare professionals significantly reduces the patient's chances of contracting caronavirus.The article proposes a device design that allows for remote automatic monitoring of patients' condition being treated at home by an observing medical professional.With the proposed device's help, the patient's blood oxygen saturation level is automatically and remotely controlled. The device is built on an Arduino board.The use of the device greatly reduces the likelihood of contracting caronavirus in patients receiving home treatment.This could be one of the most important decisions in maintaining the health of the population today.

scholarly journals Automatic Oxygen Delivery System for Premature Babies

2010 ◽  
Vol 4 (2) ◽  
Author(s):  
Thao P. Do ◽  
Lindsey J. Eubank ◽  
Devin S. Coulter ◽  
John M. Freihaut ◽  
Carlos E. Guevara ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
Oxygen Concentration ◽  
Delivery System ◽  
Pulse Oximeter ◽  
Oxygen Delivery ◽  
Supplemental Oxygen ◽  
Saturation Level ◽  
Blood Oxygen ◽  
Blood Oxygen Saturation ◽  
Oxygen Saturation Level

When an infant is born prematurely, there are a number of health risks. Among these are underdeveloped lungs, which can lead to abnormal gas exchange of oxygen or hypoxemia. Hypoxemia is treated through oxygen therapy, which involves the delivery of supplemental oxygen to the patient but there are risks associated with this method. Risks include retinopathy, which can cause eye damage when oxygen concentration is too high, and brain damage, when the concentration is too low [1]. Supplemental oxygen concentration must be controlled rigorously. Currently healthcare staff monitors infants’ blood oxygen saturation level using a pulse oximeter. They manually adjust the oxygen concentration using an air-oxygen blender. Inconsistent manual adjustments can produce excessive fluctuations and cause the actual oxygen saturation level to deviate from the target value. Precision and accuracy are compromised. This project develops an automatic oxygen delivery system that regulates the supplemental oxygen concentration to obtain a target blood oxygen saturation level. A microprocessor uses a LABVIEW® program to analyze pulse oximeter and analyzer readings and control electronic valves in a redesigned air-oxygen blender. A user panel receives a target saturation level, displays patient data, and signals alarms when necessary. The prototype construction and testing began February 2010.

Acute Normovolemic Hemodilution Improves Oxygenation in Ischemic Flap Tissue

2002 ◽  
Vol 96 (6) ◽  
pp. 1478-1484 ◽  
Author(s):  
Sören Schramm ◽  
Reto Wettstein ◽  
Robert Wessendorf ◽  
Stephan M. Jakob ◽  
Andrej Banic ◽  
...  
Keyword(s):  
Blood Flow ◽  
Oxygen Tension ◽  
Base Excess ◽  
Hemoglobin Concentration ◽  
Linear Increase ◽  
Control Group ◽  
Total Blood ◽  
Normovolemic Hemodilution ◽  
Total Blood Flow ◽  
Ischemic Flap

Background The flaps used in reconstructive surgery are prone to ischemia and hypoxia, which imply a considerable risk of wound-healing complications. During normovolemic hemodilution, the oxygenation may further deteriorate because of the lack of erythrocytes or improve because of increased microcirculatory blood flow. The aim of this study was to investigate the net effect of normovolemic hemodilution of various degrees on the microcirculation and oxygenation in ischemic flap tissue in adult minipigs. Methods A rectangular flap was raised in the middle of the epigastrium, consisting of an adequately perfused portion and a partly ischemic portion. The animals were randomly assigned to either the control group (n = 10) or the experimental group (n = 10) receiving graded normovolemic hemodilution with 6% hydroxyethyl starch 200-0.5. Results Normovolemic hemodilution caused a significant linear increase in total blood flow to the flap (measured by transit time flowmetry). In the ischemic flap tissue, both oxygen tension (measured by polarographic cells) and venous base excess were transiently improved during hemodilution (F = 4.79 and P = 0.019 for the regression of tissue oxygen tension on hemoglobin and hemoglobin squared, and F = 4.18 and P = 0.029 for base excess). The expected values reached a peak at hemoglobin concentrations of 9.1 and 8.5 g/dl, respectively. The measured values at this level of hemodilution were 17 +/- 10.7 mmHg (mean +/- SD) versus 7.6 +/- 1.9 mmHg (baseline) for oxygen tension and -1.7 +/- 3.4 versus -5.6 +/- 4.1 mM for venous base excess. Conclusions Our results suggest that the oxygenation in ischemic and hypoxic flap tissue may be improved by normovolemic hemodilution. The maximal benefit may be expected at a hemoglobin concentration at or slightly less than 9 g/dl.

Osmotic and volaemic effects on drinking rate in elasmobranch fish

2002 ◽  
Vol 205 (8) ◽  
pp. 1115-1122 ◽  
Author(s):  
W. Gary Anderson ◽  
Y. Takei ◽  
N. Hazon
Keyword(s):  
Sea Water ◽  
Plasma Osmolality ◽  
Fold Increase ◽  
Total Blood Volume ◽  
Elevated Plasma ◽  
Total Blood ◽  
Drinking Rate ◽  
Scyliorhinus Canicula ◽  
Drinking Response ◽  
Elasmobranch Fish

SUMMARYAn increase in drinking rate of two species of marine elasmobranch fish, Scyliorhinus canicula and Triakis scyllia, acclimated to 80% sea water was observed following the introduction of 100 % sea water to experimental tanks. The drinking response in both species was found to be maximal within 6 h, and a significant increase was sustained for up to 24 h in T. scyllia. Plasma osmolality was significantly increased within 6 h following introduction of 100 % sea water, and this increase was principally due to elevated plasma Na+ and Cl- concentrations. Administration of 2 mol l-1 mannitol, 75 % sucrose and vehicle(elasmobranch Ringer) did not induce a significant increase or decrease in the drinking rate of S. canicula. However, injection of 20 % NaCl was found to decrease drinking rate significantly in S. canicula 60 min after administration. Controlled haemorrhage of approximately 5.7 % of total blood volume in S. canicula induced a rapid 36-fold increase in drinking over basal levels. The present study demonstrates a physiological dipsogenesis in response to hypovolaemia in marine elasmobranch fish as part of their overall iso/hyperosmoregulatory strategy.

Differences in reactive hyperemia between the intestinal mucosa and muscularis

1984 ◽  
Vol 247 (6) ◽  
pp. G617-G622
Author(s):  
A. P. Shepherd ◽  
G. L. Riedel
Keyword(s):  
Blood Flow ◽  
Metabolic Rate ◽  
Laser Doppler Velocimetry ◽  
Reactive Hyperemia ◽  
Arterial Occlusion ◽  
Oxygen Demand ◽  
Laser Doppler ◽  
Doppler Velocimetry ◽  
Total Blood ◽  
Total Blood Flow

In a previous study of regional intestinal blood flow by laser-Doppler velocimetry, we noted that the mucosa displayed reactive hyperemia following arterial occlusion but that the muscularis did not. Therefore, to determine whether this observation is generally valid, we compared responses of the mucosa and muscularis externa to arterial occlusion. We measured total blood flow to isolated loops of canine small bowel with an electromagnetic flow probe on the supply artery; blood flow either in the mucosa or in the muscularis was measured by laser-Doppler velocimetry. Mucosal and total blood flow consistently showed reactive hyperemia in response to a 60-s occlusion, but the muscularis did not. To determine whether metabolic rate influenced reactive hyperemia, we increased enteric oxygen uptake by placing 5% bile and transportable solutes in the lumen; these agents increased oxygen consumption by 36%. After a 60-s occlusion, the durations of both total and mucosal reactive hyperemia were significantly prolonged by increased metabolic rate. Similarly, the payback-to-debt ratios in both total and mucosal blood flows were significantly increased at elevated metabolic rate. These data support the conclusions that reactive hyperemia occurs more frequently and has a greater magnitude in the mucosa compared with the muscularis and both total and mucosal reactive hyperemia are strongly influenced by the preocclusive oxygen demand. These findings therefore constitute further evidence that metabolic factors contribute to reactive hyperemia in the intestinal circulation.

Growth of four species of juvenile fish associated with the Seagrass Zostera capricorni, in Botany Bay, NSW

1992 ◽  
Vol 43 (5) ◽  
pp. 1189 ◽  
Author(s):  
DG Worthington ◽  
DJ Ferrell ◽  
SE NcNeill ◽  
JD Bell
Keyword(s):  
Sea Water ◽  
New South ◽  
Juvenile Fish ◽  
Natural Populations ◽  
Length Frequency ◽  
Frequency Distributions ◽  
South Wales ◽  
Time Period ◽  
Flow Through ◽  
Sampling Programme

Populations of four species of juvenile fish- Rhabdosargus sarba, Acanthopagrus australis, Achoerodus viridis and Girella tricuspidata-were sampled from a seagrass bed in Botany Bay, New South Wales. Fish were collected eight times between 22 March 1990 and 22 February 1991, using a small seine-net. Growth rates were calculated from the progression of cohorts in length-frequency distributions. Cohorts of R. sarba, A. australis and A. viridis grew most slowly during winter (0.02, 0.04 and 0.21 mm day-1, respectively); growth then increased, peaking just prior to the loss of the cohort from the habitat (0.3 1, 0.24 and 0.39 mm day-1). Populations of R. sarba, A. australis and A. viridis were comprised of one or two cohorts that remained in the habitat for at least 3-4 months. Conversely, up to seven cohorts of G. tricuspidata were found between October and February, and most cohorts did not remain in the habitat for more than 2 months. As a result, there were only two confident estimates of growth for G. tricuspidata: 0.23 mm day-1 between October and November, and 0.34 mm day-1 between January and February. Individuals of each species were also kept in a flow-through 4000-L tank of sea water. Growth of cohorts of fish kept in the tank was very similar to that found in natural populations during the same time period. The rates of recruitment and loss of cohorts from seagrass can be rapid and these factors must be considered in designing a sampling programme to assess growth by analysis of length-frequency distributions.

Alterations of mature arterioles associated with chronically reduced blood flow

1993 ◽  
Vol 264 (1) ◽  
pp. H40-H44 ◽  
Author(s):  
D. H. Wang ◽  
R. L. Prewitt
Keyword(s):  
Blood Flow ◽  
Vascular Wall ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Adaptive Responses ◽  
Total Blood ◽  
Cross Sectional ◽  
Old Rats ◽  
Total Blood Flow ◽  
Autoregulatory Mechanism

Adaptive responses of mature arterioles were examined after a 38% reduction in total blood flow to the cremaster muscle produced by unilateral orchidectomy in 12-wk-old rats. Four weeks later, the muscle was smaller than the contralateral cremaster, which did not increase in size during this period. Measured by closed-circuit television microscopy, the internal diameters of first- through fourth-order arterioles (1A-4A) were smaller, but wall cross-sectional area was reduced only in 3As. The smaller diameter of the 1A in the orchidectomy muscle resulted in unchanged wall shear rate. As determined from the perfusion-fixed, microfilled cremaster muscles, the total length of the arcading arterioles and the number of 3As were not statistically different, but the total number of 4As was significantly reduced on the orchidectomy side. Therefore, chronic load reduction in a mature muscle resulted in reduced blood flow, decreased number of 4As, and smaller arteriolar internal diameters in the absence of net changes in vascular wall cross-sectional area. A local autoregulatory mechanism related to flow-induced shear stress is suggested as the mechanism mediating the changes.

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