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Biomedical subjects

E A Konza

Publications and source records attributed to E A Konza.

13 recordsLinked to original sources
PubMed1985

[Reactions of the external respiration in waking dogs to hypercapnia].

The volume and temporal characteristics of lung ventilation were studied under conditions of progressing hypercapnia in 4 alert dogs. Similarity of ventilatory sensitivity for CO2 and of respiration patterns was revealed in all the dogs. The contribution of frequency component was negligible. The hypercapnic hyperpnoe was followed by a shortening of expiration duration along with unaltered (or increased) duration of inspiration.

Animals↗
PubMed1983

[Breathing pattern in the waking dog].

The parameters of lung ventilation: the tidal volume, the duration of inspiration and expiration as well as their derivatives, were recorded repeatedly in alert dogs. An obvious variability of patterns of respiration at a relatively stable level of ventilation was revealed. A positive correlation was found between the tidal volume and the cycle duration, particularly the inspiratory phase of the latter, which seems to maintain the isoventilatory character of the observer pericdic array not of the pattern.

Animals↗
PubMed1980

[Resistive loading and mechanisms regulating respiration].

In experiments on anesthetized cats, switch on of additional inelastic respiration resistance (resistive load) produced, apart from slowing of the respiratory flows, an increase in the activity of motoneurons and inspiratory intrathoracic pressure. Bilateral vagotomy resulted in disappearance of resistive load-induced elevation of the phrenic nerve activity, but did not abolish the growth of the inspiratory effort. Analysis of the evidence obtained indicates that activation of phrenic motoneurons associated with increased respiration resistance is underlain by prolongation of the inspiratory phase that is consequent on relaxation of the inspiratory inhibition. It is suggested that, in addition to the mechanism depicted, the compensatory reaction to the resistive load involves, apart from diaphragm participation, other inspiratory muscles as well as enhanced contractions of respiratory muscles provided by the properties of muscular fiber.

Abdominal Muscles↗
PubMed1979

[Regulation of breathing in conditions of changed gas density and with resistance loading].

In anesthetized cats, an additional resistance for breathing entailed an increase in the work of respiratory muscles and some deceleration of respiratory cycles, particularly during hyperpnoe caused by hypercapnia. Inhalation of a mixture of increased density (SF6-O2) exerted a similar effect. The compensatory increase in the work of respiratory muscles persisted after bilateral vagotomy whereas the response to inhalation of the mixture disappeared. This suggests that extravagal reflexes take part in optimization of breathing in conditions of external resistance whereas the effect of high density of inhaled gas developes, mainly, through the afferent system of the lungs.

Airway Resistance↗
PubMedDate not supplied

[Responses of the respiratory system to changes in gas density at different inspiratory flow rates].

The effect of altered gas density on the respiratory function was investigated in relation to the velocity of gas flows in airways. In the normal man breathing of normoxic He-O2 (with a density of 0,34 as compared to air) slightly decreased and inhalation of SF6-O2 (with a density of 4.2) significantly increased the metabolic rate of 1 1 ventilation. These effects were distinct when inspiratory flows reached threshold values. In anesthesized cats, He-O2 breathing reduced inspiratory activity upon forced respiration, and SF6-O2 breathing increased it upon quiet respiration. These findings can be used to predict limiting densities of respiratory mixtures for a normal man performing physical work of a certain load undersea.

Animals↗