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T N Shimaraeva

Publications and source records attributed to T N Shimaraeva.

7 recordsLinked to original sources
PubMed1990

[Respiration in the cat following destruction of the dorsal respiratory nucleus].

The effect of the lesion of dorsal respiratory nucleus (DRN) upon the duration of respiratory phases, lung ventilation and the symmetry of excitation of diaphragmatic nerves, was studied in decerebrated cats. The lesion entailed an elongation of inspiration (by 61%) and expiration (by 29%), increased the CO2 contents in alveolar air (by 12%), decreased the lung ventilation per minute (by 15%) and did not disturb the symmetry of excitation of both diaphragmatic nuclei. No apneustic respiration was observed. The data obtained suggest the DRN participation in the mechanism of the inspiration switching off and the presence of the control systems coordinating the excitation of symmetrical pools of diaphragmatic motoneurons.

Animals↗
PubMed1983

[Hering and Breuer reflexes in kittens in the early stages of postnatal ontogeny].

In 16 one to twelve-day old decerebrate kittens with intact nn. vagi, the reflex responses to trachea occlusion and alteration of the lung volume were studied. The EMGs of diaphragm and intercostal muscles were recorded as well as the tidal volume and the intratracheal pressure. The character of responses to above stimuli is similar in kittens and in adult cats. The trachea occlusion induces a greater elongation of expiration in kittens. Both in newborn and adult cats there is no obvious difference in intensity of expiratory-facilitating reflex in response to lung inflation. The threshold of inspiratory-exciting reflex in response to augmentation of the lung volume is relatively high in kittens. This reflex as well as the reflex to the lung collapse can be less regularly induced than in adults. It can be assumed that the sensitivity of bulbar respiratory center to impulses from the lung mechanoreceptors is relatively high in newborn animals.

Animals↗
PubMed1982

[Importance of the receptors in the chest wall for regulating diaphragmatic excitation in the early stages of postnatal ontogeny].

Extravagal responses to trachea occlusion, lungs expansion and sucking off the air from lungs in decerebrated vagotomized kittens of 1--12-day age were as uncertain and irregular as in growing cats. Intensity of the extravagal responses is much weaker than the reflexes to stimulation of the lung receptors. No changes of character or obviousness of effects of the thoracic walls receptors on the diaphragm motoneurons seem to occur in the course of postnatal ontogenesis.

Animals↗
PubMed1979

[Effect of spinal cord section on extravagal diaphragmatic reflexes].

In anesthetized vagotomized cats breathing under resting conditions, responses of the phrenic motoneurons to tracheal occlusion, and to changes of the lung and chest volumes were studied before and after cordotomy between C6 and T1. The cordotomy did not change the breathing rate whereas the inspiratory period shortened and expiratory one became longer. The cordotomy eliminated the slight shortening of inspiration in response to tracheal occlusion. The slight decrease of inspiratory excitation of phrenic motoneurons and prolongation of the expiration in response to tracheal occlusion remained. After the cordotomy the increase and decrease of chest volumes were not accompanied by any consistent changes in activity of the phrenic motoneurons.

Animals↗
PubMed1978

[Effect of phrenicotomy on extravagal diaphragmatic reflexes].

In experiments on decerebrated or anesthetized with nembutal and vagotomized cats responses of phrenic motoneurons were studied before and after bilateral phrenicotomy. The tracheal occlusion and changes of the lung and chest volumes were used as stimuli. Phrenicotomy did not eliminate the responses. As before the diaphragm denervation, tracheal occlusion evoked only a small shortening of inspiration, extending of the expiration and respiratory cycle, decreasing the amplitude of activity of the phrenic nerve. In response to lung inflation expiration was a little shortened. With lung deflation activity of phrenic motoneurons was not changed. Impulses of the diaphragm mechanoreceptors and excitatory intercostal-to-phrenic reflex from caudal intercostal proprioceptors had no significance in regulation of activity of phrenic motoneurons in response to tracheal occlusion and changes of the lung and chest volumes in decerebrated and anesthetized cats.

Anesthesia, General↗
PubMed1976

[Role of extravagal reflexes in regulating diaphragmatic excitation following tracheal occlusion and changes volume of the thoracic cavity in cats].

Decerebrated vagotomized cats after tracheal occlusion developed a slight but significant decrease in duration of inspiration, respiratory cycle, and in amplitude of diaphragmatic nerve ENG. Deflation (10-30 ml) or inflation (20-60 ml) of the lungs produced no changes in activity of diaphragmatic motorneurons. A stronger inflation (80-100 ml) decreased the expiratory phase activity. After bilateral vagotomy only slight and inconstant changes of respiratory rhythm were observed.

Animals↗