[Regulation of respiration: visceral and behavioural components].

The review segregates two aspects of respiration regulation: autonomous respiration regulation as a visceral function ensuring metabolic needs of a body by maintaining stability of own respiratory environment, on the one hand, and behavioural regulation of respiration under control of the volitional sphere, on the other hand. The authors focus on respiratory rythmogenesis, the problem that has not yet been resolved, and on the mechanism of precise correlation of lung ventillation with the metabolic level, in case of muscular exercise, in particular. The authors discuss interaction of visceral and behavioural mechanisms of respiratory regulation. The substance of the phenomenon of respiratory embarrassment is considered in this connection as a visceral signal addressed to the behavioural sphere. Reasonableness of introduction of a new breathing system in a healthy person is doubted. The article justifies the pracice of bioregulation of the respiratory function.

[Human respiratory sensory system, its physiological role]. / Dykhatel'naia sensorika cheloveka, ee fiziologicheskaia rol'.

Modern data on genesis and functional role of sensations associated with respiration, were analysed. Regularities of human perception of the respiratory cycle's parameters have been cited. Respiratory discomfort occurring in an increased loading of the respiratory system, as well as an imperative respiration stimulus developing in a prolonged apnoe or obvious hypoventilation, are regarded as defensive responses to a threat to normal ventilation of the lungs. The central link in mechanisms of the respiratory sensory system seems to involve pulses from receptors of the respiratory muscles.

[Physical performance and function of the cardiorespiratory system in additional respiratory resistance]. / Fizicheskaia rabotosposobnost' i funktsii kardiorespiratornoi sistemy pri dobavochnom soprotivlenii dykhaniiu.

This paper presents results of examining respiration and circulation parameters of healthy volunteers pedalling a bicycle ergometer at different degrees of inspiratory-expiratory resistance. In this situation the performance-limiting factor is an increased load on respiratory muscles. An additional signal of performance problems is respiratory discomfort. The paper gives a formula for predicting maximally allowable workloads in response to increased respiration resistance.

[Initial expiratory activity as one of the criteria of the respiratory center function]. / Nachal'naia ékspiratornaia aktivnost' kak odin iz kriteriev funktsii dykhatel'nogo tsentra.

In 13 healthy men at rest and dosed muscular loads the authors studied maximal rates of the mouth pressure at the onset of inhalation and expiration (dP/dtI, dP/dtE) as well as the respiratory pattern. The parameter dP/dtE positively correlated with that of dP/dtI which reflects, as is known, an inspiratory activity of the respiratory center. The authors think that dP/dtE parameter can be used for noninvasive determination of expiratory activity.

Ventilatory response kinetics and breathing pattern during exercise at different chemoreceptive drives.

For studying the effects of different chemoreceptive drives on the ventilatory responses to muscular work, experiments were carried out with 16 healthy men. They accomplished a 5-min exercise while breathing with different gas mixtures or after hyperventilation. As was shown, the rapid component of the exercise hyperpnea increased with intensifying the hypercapnic and/or hypoxic stimuli and was reduced or abolished with attenuation of these stimuli. At this, hypoxic drive exerted primary influence on the response kinetics. In the steady-state exercise effects of the chemoreceptive stimuli were modulated by biomechanical factors, which leads to a energetically optimum breathing pattern being formed.

[Effect of increased respiratory resistance on human work capacity]. / Vliianie uvelichennogo soprotivleniia dykhaniiu na rabotosposobnost' cheloveka.

Respiratory responses to external resistive resistance are discussed, having in view data in the literature and experimental results obtained by the present authors. The adverse changes induced by this factor during muscle work are described with special emphasis on performance deterioration. Some considerations are presented which are related to the physiological implications of the maximal allowable values of respiratory resistance produced by the breathing system upon workloads of various intensity and duration.

[The role of sensory components in reactions of the human respiratory system to increasing loads]. / Ro'l sensornykh komponentov v reaktsiiakh respiratornoi sistemy cheloveka na narastaiushchie nagruzki.

In 13 healthy male subjects performing an increasing work on veloergometer in conditions of resistive respiratory loads, the moments of sensation of respiratory difficulties and refusal from the work, were recorded. The analysis of the respiratory system functions revealed that the respiratory discomfort occurred with increasing of the alveolar PCO2 up to a certain value and that the refusal occurred on a certain level of inspiratory activity. The subjects believed that the moment of refusal coincided with the complete exhaustion of the respiratory system reserves. Their lung ventilation, however, as well as inspiratory effort were far from reaching the maximal values obtained in special tests. Apparently, the sensory components of responses to the combination of muscular work with an increased resistance against breathing are of a defensive character and directed to the prevention of the exhaustion of the respiratory system functional reserves.

[Regulation of human respiration during a combination of resistive loading and muscular activity]. / Reguliatsiia dykhaniia cheloveka pri sochetanii rezistivnoi nagruzki i myshechnoi deiatel'nosti.

In 9 healthy subjects, effects of additional non-elastic resistance (the resistive load) on parameters of the respiration control were shown to be slight in resting whereas in muscular activity they involved a rearrangement of the respiration pattern and a considerable increase of inspiratory and expiratory activities. As opposed to these adaptive responses, however, the resistive load, the inspiratory-expiratory one in particular, reduced the increment of lung ventilation associated with the load, and led to a hypercapnia. Physiological mechanisms of these shifts are discussed.