Respiration physiology
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Recent papers in Respiration physiology
Increased circadian variability of airway caliber is a key feature of asthmatic patients, but it has not been addressed in animal models of asthma. Furthermore, animal studies on circadian rhythmicity of airway resistance are very scanty.... more
Elephants have had to adapt to gravitational stresses imposed on their very large respiratory structures. We describe some unusual features of the elephant's respiratory system and speculate on their functional significance. A... more
The quality of morphometric data obtained by stereological methods depends on the sampling scheme adopted. In the light of recent advances in sampling theory for stereology a sampling strategy has been developed which differs... more
The concept of 'vascular waterfall' has been used for collapsible vessels in different hemodynamic states which have little similarity to each other from a dynamic standpoint. Examples include (a) flow through large systemic veins... more
In these studies, we determined the contribution of central mechanisms and the role of GABA(A)-receptor signal transduction pathways in mediating hypercapnia-induced slowing of breathing frequency. Experiments were performed in... more
We investigated structural characteristics for high O2 flux in hummingbird flight muscle, i.e. the most O2 demanding skeletal muscle per unit tissue mass among vertebrates. Pectoralis and supracoracoideus muscles of 3-4 g hummingbirds... more
The recruitment and derecruitment of lung units is one explanation of the hysteresis observed in an excised lung during inflation and deflation. A simplified model has been proposed in which the recruitment-derecruitment process is a... more
The effects of sustained constriction of the rib cage (RCC), constriction of the abdomen (AC) and of breathing against a positive pressure of 10 cms of water (PPB) were studied in four normal subjects with moderate constant hypercapnia.... more
Blood flow into the pulmonary capillaries and the volume of blood within the capillary bed are both pulsatile with the cardiac cycle. We have developed a quantitative model of diffusional gas exchange in the lung to investigate the... more
We have investigated structure and function of the external gill filaments, which occur transiently in the embryonic little skate, Raja erinacea. Approximately 25-30 days after spawning (body mass 0.03-0.05 g) external gill filaments... more
The lungs of 7 children (age: 26 days to 5 years 4 months) who died from non-respiratory causes were morphometrically investigated by means of light and electron microscopy. For analysis, the set of data was supplemented with results... more
Using a mathematical model, the effects of water and blood flow inequality on gas exchange in the fish gill were investigated. The results show that O2 exchange is more sensitive to flow inequalities than CO2 exchange. Oxygen exchange is... more
To detect and quantify diffusion limitation in alveolar-capillary O2 transfer, measurements of pulmonary gas exchange were performed in 6 awake, chronically tracheostomized dogs (mean body weight 28.3 kg) breathing low O2 (arterial PO2... more
The effects of recurrent hypoxia on cardiorespiratory reflexes were characterized in anesthetized piglets at 2-10 d (n=15), 2-3 weeks (n=11) and 8-10 weeks (n=8). Responses of phrenic and hypoglossal electroneurograms (ENG(phr) and ENG... more
Respiratory diseases are a frequent reason for using health care. In 1995-1996, diseases of the respiratory tract (ICD 460-519) contributed seven of the top 15 reasons for visits to physician offices among children under 15 years of age... more
To quantify any mechanical inhibitory effect of nasal intermittent positive pressure ventilation (IPPV) on inspiratory activity of the diaphragm we ventilated five conscious relaxed subjects on two occasions at respiratory rates similar... more
To assess the suitability of the miniature swine for studies of the control of breathing we evaluated the response of these animals to commonly used respiratory stimuli. Hanford miniature pigs were anesthetized with alpha chloralose and... more
A computer program is described, relating blood flow with venous PO2 for any given set of the following parameters: oxygen uptake, respiratory quotient, the 2,3-DPG/Hb molar concentration ratio (G), arterial PO2, PCO2, and pH. Two... more
The aim of this ex-vivo study on excised tracheas of healthy horses was to characterise the microscopic heterogeneity of mucus quality by a visual grading system based on transparency and to determine whether differences in mucus quality,... more