scholarly journals Effects of environmental hypoxia and hypercarbia on ventilation and gas exchange in Testudines

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5137 ◽  
Author(s):  
Pedro Trevizan-Baú ◽  
Augusto S. Abe ◽  
Wilfried Klein
Keyword(s):  
Oxygen Consumption ◽  
Quantitative Analysis ◽  
Gas Exchange ◽  
Respiratory System ◽  
Environmental Conditions ◽  
Breathing Pattern ◽  
Trachemys Scripta ◽  
System A ◽  
Ventilatory Pattern ◽  
Ventilatory Parameters

BackgroundVentilatory parameters have been investigated in several species of Testudines, but few species have had their ventilatory pattern fully characterized by presenting all variables necessary to understand changes in breathing pattern seen under varying environmental conditions.MethodsWe measured ventilation and gas exchange at 25 °C in the semi-aquatic turtleTrachemys scriptaand the terrestrial tortoiseChelonoidis carbonariusunder normoxia, hypoxia, and hypercarbia and furthermore compiled respiratory data of testudine species from the literature to analyze the relative changes in each variable.ResultsDuring normoxia both species studied showed an episodic breathing pattern with two to three breaths per episode, but the non-ventilatory periods (TNVP) were three to four times longer inT. scriptathan inC. carbonarius. Hypoxia and hypercarbia significantly increased ventilation in both species and decreased TNVPand oxygen consumption inT. scriptabut not inC. carbonarius.DiscussionContrary to expectations, the breathing pattern inC. carbonariusdid show considerable non-ventilatory periods with more than one breath per breathing episode, and the breathing pattern inT. scriptawas found to diverge significantly from predictions based on mechanical analyses of the respiratory system. A quantitative analysis of the literature showed that relative changes in the ventilatory patterns of chelonians in response to hypoxia and hyperbarbia were qualitatively similar among species, although there were variations in the magnitude of change.

scholarly journals ARRHYTHMIC BREATHING, APNEA AND NON-STEADYSTATE OXYGEN UPTAKE IN HIBERNATING LITTLE BROWN BATS (MYOTIS LUCIFUGUS)

1990 ◽  
Vol 149 (1) ◽  
pp. 395-406
Author(s):  
DONALD W. THOMAS ◽  
DANIELLE CLOUTIER ◽  
DANIEL GAGNÉ
Keyword(s):  
Oxygen Consumption ◽  
Gas Exchange ◽  
Oxygen Uptake ◽  
Breathing Pattern ◽  
Adaptive Strategies ◽  
Open Circuit ◽  
Myotis Lucifugus ◽  
O2 Uptake ◽  
Closed Glottis ◽  
Little Brown Bats

We measured the breathing pattern and oxygen consumption of hibernating little brown bats {Myotis lucifugus) in open- and closed-circuit metabolic chambers. At 5°C, hibernating M. lucifugus showed bouts of ventilation lasting on average 1.24min and separated by periods of apnea lasting on average 47.59min. The bats consumed 0.014 ml O2g−1 during ventilation bouts and 0.002 ml g−1 during apnea. The total O2 uptake was 0.016 ml g−1 for a complete ventilationapnea cycle, giving a Vo2 of 0.020 ml g−1 h−11. This value is considerably lower than most values previously published for Myotis spp. and we suggest that studies using open-circuit systems that did not account for the intermittent nature of gas exchange during hibernation may be in error. Based on the dimensions of the respiratory tract, we estimate that 0.026 ml O2g−1h−1 and 0.009mlCO2g−1h−1 could diffuse down the tract if the glottis was open. The low O2 uptake during apnea indicates that the glottis was closed. If CO2 retention acts to depress metabolism in hibernators, a closed glottis and arrhythmic breathing may be adaptive strategies in hibernation.

Acute Cardio-respiratory responses of Spangled Perch, Leiopotherapon unicolor (Gunther 1859), to Sublethal concentrations of Zinc, Temephos and 2,4-D

1988 ◽  
Vol 39 (6) ◽  
pp. 767 ◽  
Author(s):  
PC Gehrke
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Gas Exchange ◽  
Respiratory System ◽  
Ventilation Rate ◽  
Cholinesterase Inhibition ◽  
Gill Epithelium ◽  
Arterial Blood ◽  
Sublethal Concentrations ◽  
Respiratory Responses

Spangled perch, Leiopotherapon unicolor, were exposed to concentrations of 5.0, 10 or 20 mg 1-1 zinc, 0.1, 1.0 or 10 mg 1-1 temephos or 0.1, 1.0 or 10 mg 1-1 2,4-D at 25�C for 2 h, during which time ventilation rate, heart rate and oxygen consumption were continuously monitored. Fish exposed to 10 and 20 mg 1-1 zinc demonstrated a significant increase in ventilation rate; those exposed to 20 mg 1-1 also developed a significant bradycardia. Exposure to 10 mg 1-1 temephos caused an immediate reduction in ventilation rate and oxygen consumption, and also reduced heart rate during the second hour of exposure. Fish exposed to 10 mg 1-1 temephos died within 12 h. Responses of fish to 2,4-D gave no indication of toxic effects on the cardio-respiratory system. Cardio-respiratory responses to zinc are attributed to damage caused to the gill epithelium, which results in impaired gas exchange and lowered oxygen tension in arterial blood. Effects of exposure to temephos correspond to cholinesterase inhibition in nerves supplying the respiratory musculature and the heart.

scholarly journals Letter to the Editor: Microbiota in the Respiratory System—A Possible Explanation to Age and Sex Variability in Susceptibility to SARS-CoV-2

2021 ◽  
Vol 14 ◽  
pp. 117863612098860
Author(s):  
Vishal Shah
Keyword(s):  
Respiratory System ◽  
Elderly Population ◽  
Age Groups ◽  
The Elderly ◽  
Elderly Adult ◽  
Human Respiratory Tract ◽  
System A ◽  
Number Of Patients ◽  
Children And Young Adults ◽  
Age And Sex

The Human respiratory tract is colonized by a variety of microbes and the microbiota change as we age. In this perspective, literature support is presented for the hypothesis that the respiratory system microbiota could explain the differential age and sex breakdown amongst COVID-19 patients. The number of patients in the older and elderly adult group is higher than the other age groups. The perspective presents the possibility that certain genera of bacteria present in the respiratory system microbiota in children and young adults could be directly or through eliciting an immune response from the host, prevent full-fledged infection of SARS-CoV-2. The possibility also exists that the microbiota in older adults and the elderly population have bacteria that make it easier for the virus to cause infection. I call upon the scientific community to investigate the link between human microbiota and SARS-CoV-2 susceptibility to further understand the viral pathogenesis.

Thermographic signs of certain diseases of the respiratory system (acute sinusitis, pneumonia) Thermography Atlas

2021 ◽  
Author(s):  
I. Dolgov ◽  
Mihail Volovik ◽  
Andrey Mahnovskiy
Keyword(s):  
Clinical Practice ◽  
Quantitative Analysis ◽  
Respiratory System ◽  
Thermal Imaging ◽  
Temperature Gradients ◽  
Analysis Program ◽  
Present Issue ◽  
Paranasal Sinusitis ◽  
Body Regions ◽  
Thermal Phenomenon

The present issue focuses on the practice of medical thermal imaging in patients with paranasal sinusitis and pneumonia. The description of thermograms is based on a quantitative analysis of temperature gradients and trends in temperature of different body regions (Projection «head front» for paranasal sinusitis, «breast front» and «back», in a defined layout formed in «cloud» thermograms analysis program "Tvision" of «Dignosis», Russia) with values of thermographic markers that demonstrated their differentiating capabilities when compared with reference methods. Thus, the thermographic conclusion is formed not simply by thermal phenomenon «hot-cold», but on the basis of numerical values of markers, which indicate hypothetical nosological diagnosis and significantly simplifies the algorithm for those physicians who use this method as an additional. The publication is intended for doctors of any speciality who, in their daily clinical practice, treat the patients with suspicions disease of respiratory system

Analysis of PCO2 differences during rebreathing due to slow pH equilibration in blood

1978 ◽  
Vol 45 (5) ◽  
pp. 666-673 ◽  
Author(s):  
A. Bidani ◽  
E. D. Crandall
Keyword(s):  
Quantitative Analysis ◽  
Gas Exchange ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Transport Processes ◽  
O2 Uptake ◽  
Lung Capillaries ◽  
Mixed Venous ◽  
Co2 Elimination

A quantitative analysis of the reaction and transport processes that occur in blood during and after gas exchange has been used to investigate mechanisms that might account for positive alveolar-mixed venous (A-V) and alveolar-arterial (Aa) PCO2 differences during rebreathing. The analysis was used to determine PCO2 changes that take place in blood as it travels from veins to arteries under conditions in which no CO2 is exchanged in the lung. The predicted A-V and Aa PCO2 differences are all positive and lie within the range of reported measured values. The differences are due to disequilibrium of [H+] between plasma and red blood cells, and to disequilibrium of the reactions CO2 in equilibrium HCO3- + H+ in plasma, as blood leaves the tissue and/or lung capillaries. The differences are increased with exercise and with continued O2 uptake in the lung, the latter due to the Haldane shift. We conclude that the two disequilibria and the Haldane shift contribute to the reported PCO2 differences in rebreathing animals but may not fully account for them. These mechanisms cannot explain any PCO2 differences that might exist during net CO2 elimination from blood in the lung.

scholarly journals Physiological Effects of Exercising at Different Intensities Wearing TNT or Double-layer Cotton Facemasks Compared to Not Wearing a Mask

2020 ◽  
Author(s):  
Fabrício Braga ◽  
Gabriel Espinosa ◽  
Amanda Monteiro ◽  
Beatriz Marinho ◽  
Eduardo Drummond
Keyword(s):  
Gas Exchange ◽  
Double Layer ◽  
Breathing Pattern ◽  
Pulmonary Ventilation ◽  
Effect Sizes ◽  
Moderate Intensity ◽  
List Type ◽  
Physiological Effects ◽  
Physiological Dead Space ◽  
End Tidal

Abstract We compared the physiological differences between exercising wearing a TNT or a double-layer-cotton (DLC) facemask (FM) and not wearing a mask (NM). Sixteen volunteers underwent 4 sets (S) of 2 sequential bouts (B). B1 and B2 corresponded to light and moderate intensity cycling, respectively. FMs were used as follows: S1: NM; S2: TNT or DLC; S3: DLC or TNT; and S4: NM. Metabolic, pulmonary, and perceptual variables were collected. The main results are expressed as effect sizes and confidence intervals (ES [95%CI]) for TNT and DLC unless otherwise indicated. Compared to NM, FM increased the duty cycle (B1=1.11[0.58-1.61] and 1.53[0.81-2.18]; B2=1.27[0.63-1.84] and 1.93[0.97-2.68]) and decreased breath frequency (B1=0.59[0.23-0.94] and 1.43[0.79-2.07], B2=0.39[0.05-0.71] and 1.33[0.71-1.94]). Only B1 tidal volume increased (0.33[0.09-0.56] and 0.62[0.18-1.05]) enough to avoid a ventilation reduction with TNT but not with DLC (B1=0.52[0.23-0.79]; B2=0.84[0.44-1.22]). Both FMs reduced oxygen saturation in B1 (0.56 [0.07-1.03] and 0.69 [0.09-1.28]) but only DLC did so in B2 (0.66 [0.11-1.13]). Both end tidal CO2 (B1=0.23[0.05-0.4] and 0.71[0.38-1.02]; B2=0.56[0.2-0.9] and 1.20[0.65-1.68]) and mixed-expired-CO2 (B1=0.74[0.38-1.08] 1.71[1.03-2.37], B2=0.94[0.45-1.38] and 1.78[0.97-2.42]) increased with FMs. Ventilatory adaptations imposed during FM exercising influenced blood-lung gas exchange. Larger ESs were seen with DLC. No adverse changes to human health were observed. Novelty Bullets Facemasks affect the breathing pattern by changing the frequency and amplitude of pulmonary ventilation. The augmented ventilatory work increases VO2, VCO2, and RPE and promotes non-concerning drops in SpO2 and CO2 retention. Increased inspiratory and expiratory pressure can account for the reduction in pulmonary physiological dead space.

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