The Expiratory Flow Pattern and the Neuromuscular Control of Breathing in Cats

1998 ◽  
pp. 95-100
Author(s):  
C. P. M. van der Grinten ◽  
C. K. van der Ent ◽  
N. E. L. Meessen ◽  
J. M. Bogaard ◽  
S. C. M. Luijendijk
Keyword(s):  
Flow Pattern ◽  
Neuromuscular Control ◽  
Control Of Breathing ◽  
Expiratory Flow

Expiratory flow pattern and respiratory mechanics

1987 ◽  
Vol 65 (6) ◽  
pp. 1142-1145 ◽  
Author(s):  
Jacopo P. Mortola ◽  
Anne Marie Lauzon ◽  
Brian Mott
Keyword(s):  
Flow Pattern ◽  
Respiratory System ◽  
Airway Pressure ◽  
Work Of Breathing ◽  
Vocal Folds ◽  
Resistive Load ◽  
Adult Rats ◽  
Expiratory Flow ◽  
And Control ◽  
And Diffusion

During resting breathing, expiration is characterized by the narrowing of the vocal folds which, by increasing the expiratory resistance, raises mean lung volume and airway pressure. This is even more pronounced in the neonatal period, during which expirations with short complete airway closure are commonly occurring. We asked to which extent differences in expiratory flow pattern may modify the inspiratory impedance of the respiratory system. To this aim, newborn puppies, piglets, and adult rats were anesthetized, paralyzed, and ventilated with different expiratory patterns, (a) no expiratory load, (b) expiratory resistive load, and (c) end-inspiratory pause. The stroke volume of the ventilator and inspiratory and expiratory times were maintained constant, and the loads were adjusted in such a way that inflation always started from the resting volume of the respiratory system. After 1 min of each ventilatory pattern, mean inspiratory impedance and compliance of lung and respiratory system were measured. The values were unchanged or minimally altered by changing the type of ventilation. We conclude that the expiratory laryngeal loading is not primarily aimed to decrease the work of breathing. It is conceivable that the expiratory pattern is oriented to increase and control mean airway pressure in the regulation of pulmonary fluid reabsorption, distribution of ventilation, and diffusion of gases.

scholarly journals Time to peak tidal expiratory flow and the neuromuscular control of expiration

1998 ◽  
Vol 12 (3) ◽  
pp. 646-652 ◽  
Author(s):  
C.K. van Der Ent ◽  
C.P.M. van Der Grinten ◽  
N.E.L. Meessen ◽  
S.C.M. Luijendijk ◽  
P.G.H. Mulder ◽  
...  
Keyword(s):  
Neuromuscular Control ◽  
Time To Peak ◽  
Expiratory Flow

Effect of expiratory flow patterns on lung emptying

1963 ◽  
Vol 18 (1) ◽  
pp. 47-50 ◽  
Author(s):  
A. C. Young ◽  
C. J. Martin ◽  
William R. Pace
Keyword(s):  
Carbon Dioxide ◽  
Flow Pattern ◽  
Body Position ◽  
Volume Ratio ◽  
Flow Patterns ◽  
High Flow ◽  
Low Flow ◽  
Flow Rates ◽  
Single Breath ◽  
Expiratory Flow

Differences in expired alveolar gas concentrations with changes in expiratory flow were studied in single-breath experiments using nitrogen and carbon dioxide meters. High flow rates preferentially emptied lung areas having low ventilation-to-volume ratios and high ventilation-to-perfusion ratios, whereas low flow rates preferentially emptied areas of high ventilation-to-volume and low ventilation-to-perfusion ratios. Selective emptying of different lung areas by varying the expiratory flow pattern was not affected by age, sex, or body position. A model of the lung is proposed to explain how ventilation-to-volume ratio differences can be seen at mouth level during constant slow, varying, and constantly increasing or decreasing expiratory flow. Submitted on May 4, 1962

scholarly journals Analysis of tidal expiratory flow pattern in the assessment of histamine-induced bronchoconstriction.

Thorax ◽  
1995 ◽  
Vol 50 (4) ◽  
pp. 346-352 ◽  
Author(s):  
M J Morris ◽  
R G Madgwick ◽  
D J Lane
Keyword(s):  
Flow Pattern ◽  
Expiratory Flow

Expiratory flow pattern following single-lung transplantation in emphysema.

1994 ◽  
Vol 150 (6) ◽  
pp. 1684-1689 ◽  
Author(s):  
J P Herlihy ◽  
J G Venegas ◽  
D M Systrom ◽  
R E Greene ◽  
K A McKusick ◽  
...  
Keyword(s):  
Lung Transplantation ◽  
Flow Pattern ◽  
Single Lung Transplantation ◽  
Expiratory Flow

Modeling of the expiratory flow pattern of spontaneously breathing cats

2003 ◽  
Vol 134 (1) ◽  
pp. 23-32 ◽  
Author(s):  
D. Walraven ◽  
C.P.M. van der Grinten ◽  
J.M. Bogaard ◽  
C.K. van der Ent ◽  
S.C.M. Luijendijk
Keyword(s):  
Flow Pattern ◽  
Expiratory Flow ◽  
Spontaneously Breathing

Detection of expiratory flow limitation by evaluating the spontaneous flow pattern

2011 ◽  
Author(s):  
L. S. Guimaraes ◽  
R. A. Rocha ◽  
I. Teixeira ◽  
A. C. D. Faria ◽  
P. L. Melo
Keyword(s):  
Flow Pattern ◽  
Flow Limitation ◽  
Expiratory Flow Limitation ◽  
Expiratory Flow

Morphology and development of flow-pattern defect with extended nonagitated Secco etching

1994 ◽  
Vol 52 ◽  
pp. 868-869
Author(s):  
Y. Pan
Keyword(s):  
Flow Pattern ◽  
Silicon Crystal ◽  
Gate Oxide ◽  
Crystal Growth Rate ◽  
Etch Depth ◽  
Force Microscopy ◽  
Etch Pit ◽  
Float Zone ◽  
Atomic Force ◽  
Multiple Step

The D defect, which causes the degradation of gate oxide integrities (GOI), can be revealed by Secco etching as flow pattern defect (FPD) in both float zone (FZ) and Czochralski (Cz) silicon crystal or as crystal originated particles (COP) by a multiple-step SC-1 cleaning process. By decreasing the crystal growth rate or high temperature annealing, the FPD density can be reduced, while the D defectsize increased. During the etching, the FPD surface density and etch pit size (FPD #1) increased withthe etch depth, while the wedge shaped contours do not change their positions and curvatures (FIG.l).In this paper, with atomic force microscopy (AFM), a simple model for FPD morphology by non-crystallographic preferential etching, such as Secco etching, was established.One sample wafer (FPD #2) was Secco etched with surface removed by 4 μm (FIG.2). The cross section view shows the FPD has a circular saucer pit and the wedge contours are actually the side surfaces of a terrace structure with very small slopes. Note that the scale in z direction is purposely enhanced in the AFM images. The pit dimensions are listed in TABLE 1.

No effect of artificial gravity on lung function with exercise training during head-down bed rest

2015 ◽  
pp. 1-7
Author(s):  
Longxiang Su ◽  
Yinghua Guo ◽  
Yajuan Wang ◽  
Delong Wang ◽  
Changting Liu
Keyword(s):  
Lung Function ◽  
Pulse Rate ◽  
Vital Capacity ◽  
Pulmonary Ventilation ◽  
Bed Rest ◽  
Forced Expiratory Volume ◽  
Observation Time ◽  
Artificial Gravity ◽  
Postural Changes ◽  
Expiratory Flow

AbstractTo explore the effectiveness of microgravity simulated by head-down bed rest (HDBR) and artificial gravity (AG) with exercise on lung function. Twenty-four volunteers were randomly divided into control and exercise countermeasure (CM) groups for 96 h of 6° HDBR. Comparisons of pulse rate, pulse oxygen saturation (SpO2) and lung function were made between these two groups at 0, 24, 48, 72, 96 h. Compared with the sitting position, inspiratory capacity and respiratory reserve volume were significantly higher than before HDBR (0° position) (P< 0.05). Vital capacity, expiratory reserve volume, forced vital capacity, forced expiratory volume in 1 s, forced inspiratory vital capacity, forced inspiratory volume in 1 s, forced expiratory flow at 25, 50 and 75%, maximal mid-expiratory flow and peak expiratory flow were all significantly lower than those before HDBR (P< 0.05). Neither control nor CM groups showed significant differences in the pulse rate, SpO2, pulmonary volume and pulmonary ventilation function over the HDBR observation time. Postural changes can lead to variation in lung volume and ventilation function, but a HDBR model induced no changes in pulmonary function and therefore should not be used to study AG CMs.

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