7. Integration of Central Mechanisms of Respiratory Reflexes

2015 ◽  
pp. 264-281
Keyword(s):  
Respiratory Reflexes

scholarly journals Air Pressure Responses to Sudden Vocal Tract Pressure Bleeds During Production of Stop Consonants

2004 ◽  
Vol 47 (4) ◽  
pp. 784-801 ◽  
Author(s):  
David J. Zajac ◽  
Mark C. Weissler
Keyword(s):  
Vocal Tract ◽  
Linear Trend ◽  
Upper Airway ◽  
Air Pressure ◽  
Stop Consonants ◽  
Oral Pressure ◽  
The Face ◽  
Computer Controlled ◽  
Linear Manner ◽  
Respiratory Reflexes

Two studies were conducted to evaluate short-latency vocal tract air pressure responses to sudden pressure bleeds during production of voiceless bilabial stop consonants. It was hypothesized that the occurrence of respiratory reflexes would be indicated by distinct patterns of responses as a function of bleed magnitude. In Study 1, 19 adults produced syllable trains of /pʌ/ using a mouthpiece coupled to a computer-controlled perturbator. The device randomly created bleed apertures that ranged from 0 to 40 mm 2 during production of the 2nd or 4th syllable of an utterance. Although peak oral air pressure dropped in a linear manner across bleed apertures, it averaged 2 to 3 cm H 2 O at the largest bleed. While slope of oral pressure also decreased in a linear trend, duration of the oral pressure pulse remained relatively constant. The patterns suggest that respiratory reflexes, if present, have little effect on oral air pressure levels. In Study 2, both oral and subglottal air pressure responses were monitored in 2 adults while bleed apertures of 20 and 40 mm 2 were randomly created. For 1 participant, peak oral air pressure dropped across bleed apertures, as in Study 1. Subglottal air pressure and slope, however, remained relatively stable. These patterns provide some support for the occurrence of respiratory reflexes to regulate subglottal air pressure. Overall, the studies indicate that the inherent physiologic processes of the respiratory system, which may involve reflexes, and passive aeromechanical resistance of the upper airway are capable of developing oral air pressure in the face of substantial pressure bleeds. Implications for understanding speech production and the characteristics of individuals with velopharyngeal dysfunction are discussed. KEY WORDS: stop consonants, oral air pressure, subglottal air pressure, respiratory reflexes, velopharyngeal dysfunction

Respiratory Reflexes

1983 ◽  
pp. 108-156 ◽  
Author(s):  
Andrzej Trzebski
Keyword(s):  
Respiratory Reflexes

scholarly journals Evolution of the hypoxia-sensitive cells involved in amniote respiratory reflexes

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Dorit Hockman ◽  
Alan J Burns ◽  
Gerhard Schlosser ◽  
Keith P Gates ◽  
Benjamin Jevans ◽  
...  
Keyword(s):  
Neural Crest ◽  
Blood Vessels ◽  
Carotid Body ◽  
Lineage Tracing ◽  
Neuroendocrine Cells ◽  
Genetic Lineage ◽  
Glomus Cells ◽  
Evolutionary Origins ◽  
Embryonic Origin ◽  
Respiratory Reflexes

The evolutionary origins of the hypoxia-sensitive cells that trigger amniote respiratory reflexes – carotid body glomus cells, and ‘pulmonary neuroendocrine cells’ (PNECs) - are obscure. Homology has been proposed between glomus cells, which are neural crest-derived, and the hypoxia-sensitive ‘neuroepithelial cells’ (NECs) of fish gills, whose embryonic origin is unknown. NECs have also been likened to PNECs, which differentiate in situ within lung airway epithelia. Using genetic lineage-tracing and neural crest-deficient mutants in zebrafish, and physical fate-mapping in frog and lamprey, we find that NECs are not neural crest-derived, but endoderm-derived, like PNECs, whose endodermal origin we confirm. We discover neural crest-derived catecholaminergic cells associated with zebrafish pharyngeal arch blood vessels, and propose a new model for amniote hypoxia-sensitive cell evolution: endoderm-derived NECs were retained as PNECs, while the carotid body evolved via the aggregation of neural crest-derived catecholaminergic (chromaffin) cells already associated with blood vessels in anamniote pharyngeal arches.

Respiratory reflexes in spontaneously breathing anesthetized dogs in response to nasal administration of sevoflurane, isoflurane, or halothane

2001 ◽  
Vol 62 (3) ◽  
pp. 311-319 ◽  
Author(s):  
Tatsushi Mutoh ◽  
Arata Kanamaru ◽  
Hodaka Suzuki ◽  
Hirokazu Tsubone ◽  
Ryohei Nishimura ◽  
...  
Keyword(s):  
Nasal Administration ◽  
Anesthetized Dogs ◽  
Spontaneously Breathing ◽  
Respiratory Reflexes

Respiratory Reflexes

2008 ◽  
pp. 3474-3480
Author(s):  
Donald R. Mccrimmon ◽  
George F. Alheid
Keyword(s):  
Respiratory Reflexes

Apnea of Prematurity: II. Respiratory Reflexes

PEDIATRICS ◽  
1984 ◽  
Vol 74 (1) ◽  
pp. 63-66
Author(s):  
Tilo Gerhardt ◽  
Eduardo Bancalari
Keyword(s):  
Preterm Infants ◽  
Inspiratory Effort ◽  
Control Group ◽  
Load Compensation ◽  
Airway Occlusion ◽  
Functional Immaturity ◽  
Occlusion Technique ◽  
Apnea Of Prematurity ◽  
Respiratory Reflexes

Airway obstruction is a cause of apnea in preterm infants. The activity of protective respiratory reflexes was determined in 18 preterm infants with apnea (mean of 32 episodes of more than 20 seconds duration per day) and in 18 neonates without apnea used as control subjects. This was done in order to elucidate the role of respiratory reflexes in apnea of prematurity. The infants were matched for birth weight (1,068 g v 1,065 g), gestational age (30.2 weeks v 30.2 weeks), and postnatal age (8.6 days v 8.3 days). The airway occlusion technique was used to determine the inspiratory prolongation of the occluded breath and the effective elastance of the respiratory system. Inspiratory prolongation is a measure for the reflex influence on inspiratory duration, and effective elastance reflects load compensating ability. Inspiratory prolongation was 7.3% ± 33.5% in infants with apnea and 30.6% ± 22.7% in the control group (P < .025). Effective elastance was 1.1 ± 0.5 cm H2O/mL in the apneic group and 1.5 ± 0.5 cm H2O/mL in the infants without apnea (P < .025). The results indicate that during exposure to respiratory loads, the infants with apnea maintained inspiratory effort poorly and had a decreased ability for load compensation. Their respiratory reflexes were significantly more immature than the reflex activity of the infants without apnea. This functional immaturity of respiratory reflexes may be a contributing factor in the etiology of apnea of prematurity.

Respiratory responses to aortic and carotid chemoreceptor activation in the dog

1991 ◽  
Vol 70 (6) ◽  
pp. 2539-2550 ◽  
Author(s):  
F. A. Hopp ◽  
J. L. Seagard ◽  
J. Bajic ◽  
E. J. Zuperku
Keyword(s):  
Electrical Stimulation ◽  
Carotid Body ◽  
Carotid Sinus ◽  
Chemical Stimulation ◽  
Respiratory Drive ◽  
Carotid Sinus Nerve ◽  
Nerve Activity ◽  
Respiratory Reflexes ◽  
Respiratory Responses ◽  
Stimulation Of

Respiratory responses arising from both chemical stimulation of vascularly isolated aortic body (AB) and carotid body (CB) chemoreceptors and electrical stimulation of aortic nerve (AN) and carotid sinus nerve (CSN) afferents were compared in the anesthetized dog. Respiratory reflexes were measured as changes in inspiratory duration (TI), expiratory duration (TE), and peak averaged phrenic nerve activity (PPNG). Tonic AN and AB stimulations shortened TI and TE with no change in PPNG, while tonic CSN and CB stimulations shortened TE, increased PPNG, and transiently lengthened TI. Phasic AB and AN stimulations throughout inspiration shortened TI with no changes in PPNG or the following TE; however, similar phasic stimulations of the CB and CSN increased both TI and PPNG and decreased the following TE. Phasic AN stimulation during expiration decreased TE and the following TI with no change in PPNG. Similar stimulations of the CB and CSN decreased TE; however, the following TI and PPNG were increased. These findings differ from those found in the cat and suggest that aortic chemoreceptors affect mainly phase timing, while carotid chemoreceptors affect both timing and respiratory drive.

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