Showing papers in "Respiration Physiology in 1974"

TL;DR: A general relationship between metabolic rate and incubation time is obtained; namely in different species of birds that have the same egg weight the natural incubation period is inversely related to the metabolic rate or the egg shell gas conductance.

TL;DR: The purpose of the analysis is to make a first approximation of tissue oxygenation, and to define the usefulness of venous blood as an index of mean tissue P O 2 applicable to the Krogh model.

TL;DR: The influence of temperature on the ventilatory control of Pa CO 2 when the turtles breathed air was the physiological mechanism responsible for the inverse relationship between blood pH and temperature.

TL;DR: The nomenclature of the small diameter intrapulmonary fibres as “type J” fibres is discussed and the limitations of this term, as at presently used, are outlined.

TL;DR: A secondary parabronchial network, the “neopuimo”, connecting the primary bronchus and the posterior air sacs demonstrates a changing direction of air flow in accordance with the respiratory phase.

TL;DR: It is suggested that physiological processes monitored by intrapulmonary CO 2 receptors are those which modify parabronchial P CO 2 , i.e. ventilation, venous CO 2 load, and mixed venous PCO 2 .

TL;DR: It is concluded that at high altitude a major adaptation of the chick embryo is a reduced metabolism which decreases the ΔP O 2 across the egg shell since its gas conductivity remains essentially unchanged.

TL;DR: Human arterial chemoreceptors respond more quickly to change of CO2 than of Hypoxia, and hypoxia is a prerequisite for the response of human arterialChemoreceptor to CO2: hypoxic-hypercapnic interaction is largely peripheral.

TL;DR: These receptors may be able to monitor alterations in intrapulmonary CO2 concentration resulting from changes in the metabolic activity of the bird, and may thereby be involved in the control of breathing.

TL;DR: It is concluded that panting ducks exposed to non-stressful heat loads adjust their pulmonary ventilation efficiently by greatly increasing respiratory evaporative cooling without modification of the normal acid-base balance.

TL;DR: Aquatic respiration assists the snake in feeding, augments its diving by providing supplemental oxygen and preventing respiratory acidosis through the release of carbon dioxide, and provides a site for the equilibration of inert gases to prevent caisson disease.

TL;DR: It is suggested that type I are tension receptors placed in parallel with the structures supporting the transmural pressure, whereas type II receptors are in series with these structures.

TL;DR: The findings contradict the common belief that the oxygen affinity of bird blood generally is lower than that of mammalian blood.

TL;DR: It is concluded that both nonelastic and nonhomogeneous material properties are required in order for geometrical irreversibility to be manifested, but conversely that the presence of this irreversible cannot be used to quantitatively predict or explain P-V hysteresis.

TL;DR: Tidal volume and inspiratory durations have been measured in cats anaesthetized with pentobarbitone and exposed to hypercapnia, asphyxia and hypoxia, before and after bilateral vagotomy, mainly using a rebreathing (non-steady state) method.

TL;DR: It was concluded that two types of phasic respiratory afferent fibres occur in the vagus of the hen, one from CO2-sensitive receptors the other from mechanoreceptors.

TL;DR: The results might suggest the existence of a mechanism partially responsible for the ventilatory response to carbon dioxide, since the administration of acetazolamide was found to block the eflects of CO2 on the discharge of stretch receptors.

TL;DR: Observations confirm the expectation of increased effectiveness of gas exchange in the avian lung, made possible by its arrangement as a through-flow system.

TL;DR: Investigating the hypothesis that ventilatory acclimatization of lowlanders to sojourn at 3100 m altitude is not due solely to a relative increase in medullary H + stimulation found it unlikely that the increased responses are related to [H + ] at any extra- or intracellular receptor.

TL;DR: CO 2 receptors are located in those parts of the lung that experience marked fluctuations in CO 2 concentration during the respiratory cycle, and satisfactory explanation of differences in discharge pattern of CO 2 receptors observed during spontaneous breathing is found.

TL;DR: Under conditions of both normal and loaded ventilation the opercular expiration phase dominated in its contribution to the total mean pressure generated during each breathing cycle.

TL;DR: Granular cells in the epithelium around the orifices of the craniomedial secondary bronchi were associated with axonal profiles which satisfied all the authors' criteria for being afferent endings, and the authors interpret these as a neurite-receptor cell complexes.

TL;DR: The results suggest that with cyclic ventilation, spontaneous or artificial, only two types of receptors with vagal afferents are stimulated, both of which are highly stimulus-specific.

TL;DR: Gas exchange in the amphibious fish, Amphipnous cuchia, takes place principally by air breathing, the main site of exchange being a pair of specialized pharyngeal air sacs, primarily governed by an O2-dependent chemosensitive mechanism.

TL;DR: Most single chemoreceptors of the sinus nerve of the cat and dog show oscillations in discharge in phase with respiration when summed by computer over many respiratory cycles, thought to be the respiratory oscillation of PaCO2 in the carotid blood.

TL;DR: It is concluded that all vagal afferent activity reported originated from “intrapulmonary chemoreceptors” which are sensitive to airway PCO2 and insensitive to mechanical stimulation.

TL;DR: Inspiration in the green turtle is quite comparable to the same event in mammals, but expiration is the event of special interest, because there is no well-developed conducting system in the lungs, and peak expiratory flow velocities in this turtle are not different from those of man with maximal exertion.

TL;DR: It is concluded that PaCO2; threshold for stimulating ventilation decreased during hypoxic exercise, and there was, however, no increase in the ventilatory sensitivity to hypoxia nor to hypercapnia.

TL;DR: The normal arterial chemoreflex drive of ventilation, dependent on the integrity of afferent fibers from the carotid body, is essential in determining the level of ventilation in normoxia as well as during acute hypoxia, and is also essential for normal ventilatory responses to CO2 either in transient or in steady-state conditions.

TL;DR: Volume and ventilation of the air sacs were determined in spontaneously breathing domestic ducks by an inert gas wash-out technique and functional inhomogeneity, as indicated by bi-exponential wash- out kinetics, was most pronounced in the interclavicular air sac.