Action of intercostal muscles on the lung in dogs

1991 ◽  
Vol 70 (6) ◽  
pp. 2388-2394 ◽  
Author(s):  
V. Ninane ◽  
M. Gorini ◽  
M. Estenne
Keyword(s):  
Lung Volume ◽  
Internal Layer ◽  
Airflow Rate ◽  
Intercostal Muscle ◽  
Similar Action ◽  
Rib Cage ◽  
Intercostal Muscles ◽  
Maximal Stimulation ◽  
Residual Capacity ◽  
Stimulation Of

The action on the lung of interosseous intercostal muscles located in the third and the seventh interspaces was studied in 15 anesthetized-curarized supine dogs. Changes in pleural pressure, airflow rate, and lung volume produced by maximal stimulation of both intercostal muscle layers were measured at and above functional residual capacity (FRC). In five animals measurements were also obtained during isolated stimulation of the internal layer. At FRC, intercostal stimulation in the upper interspaces had invariably an inspiratory effect on the lung but no effect was detectable in the lower interspaces. Qualitatively similar results were obtained during isolated stimulation of the internal layer. Increasing lung volume reduced the inspiratory action of the upper intercostals and conferred an expiratory action to the lower intercostals. These results indicate the following: 1) when contracting in a single interspace, the external and internal intercostals have a qualitatively similar action on the lung; and 2) this action, however, depends critically on their location along the cephalocaudal axis of the rib cage: in the upper portion of the rib cage, both muscle layers have an inspiratory effect at and above FRC; in the lower portion of the rib cage, they have no respiratory action at FRC and act in the expiratory direction at higher lung volumes.

Respiratory muscle coordination and diaphragm length during expiratory threshold loading

1991 ◽  
Vol 70 (4) ◽  
pp. 1554-1562 ◽  
Author(s):  
J. D. Road ◽  
A. M. Leevers ◽  
E. Goldman ◽  
A. Grassino
Keyword(s):  
Lung Volume ◽  
Respiratory Muscle ◽  
Abdominal Muscles ◽  
Muscle Coordination ◽  
Rib Cage ◽  
Relative Contribution ◽  
Volume Functional ◽  
Residual Capacity ◽  
Anesthetized Dogs ◽  
Expiratory Muscles

Active expiration is produced by the abdominal muscles and the rib cage expiratory muscles. We hypothesized that the relative contribution of these two groups to expiration would affect diaphragmatic length and, hence, influence the subsequent inspiration. To address this question we measured the respiratory muscle response to expiratory threshold loading in spontaneously breathing anesthetized dogs. Prevagotomy, the increase in lung volume (functional residual capacity) and decrease in initial resting length of the diaphragm were attenuated by greater than 50% of values predicted by the passive relationships. Diaphragmatic activation (electromyogram) increased and tidal volume (VT) was preserved. Postvagotomy, effective expiratory muscle recruitment was abolished. The triangularis sterni muscle remained active, and the increase in lung volume was attenuated by less than 15% of that predicted by the passive relationship. Diaphragmatic length was shorter than predicted. VT was not restored, even though costal diaphragmatic and parasternal intercostal electromyogram increased. During expiratory threshold loading with abdominal muscles resected and vagus intact, recruitment of the rib cage expiratory muscles produced a reduction in lung volume comparable with prevagotomy; however, diaphragmatic length decreased markedly. Both the rib cage and abdominal expiratory muscles may defend lung volume; however, their combined action is important to restore diaphragmatic initial length and, accordingly, to preserve VT.

Expiratory muscle contribution to tidal volume in head-up dogs

1989 ◽  
Vol 67 (4) ◽  
pp. 1438-1442 ◽  
Author(s):  
G. A. Farkas ◽  
M. Estenne ◽  
A. De Troyer
Keyword(s):  
Tidal Volume ◽  
Lung Volume ◽  
Muscle Relaxation ◽  
Rib Cage ◽  
Expiratory Muscle ◽  
Residual Capacity ◽  
Anesthetized Dogs ◽  
Expiratory Muscles ◽  
S Period ◽  
Average Contribution

A change from the supine to the head-up posture in anesthetized dogs elicits increased phasic expiratory activation of the rib cage and abdominal expiratory muscles. However, when this postural change is produced over a 4- to 5-s period, there is an initial apnea during which all the muscles are silent. In the present studies, we have taken advantage of this initial silence to determine functional residual capacity (FRC) and measure the subsequent change in end-expiratory lung volume. Eight animals were studied, and in all of them end-expiratory lung volume in the head-up posture decreased relative to FRC [329 +/- 70 (SE) ml]. Because this decrease also represents the increase in lung volume as a result of expiratory muscle relaxation at the end of the expiratory pause, it can be used to determine the expiratory muscle contribution to tidal volume (VT). The average contribution was 62 +/- 6% VT. After denervation of the rib cage expiratory muscles, the reduction in end-expiratory lung volume still amounted to 273 +/- 84 ml (49 +/- 10% VT). Thus, in head-up dogs, about two-thirds of VT result from the action of the expiratory muscles, and most of it (83%) is due to the action of the abdominal rather than the rib cage expiratory muscles.

Effect of lung volume on the respiratory action of the canine pectoral muscles

1992 ◽  
Vol 73 (6) ◽  
pp. 2408-2412 ◽  
Author(s):  
S. R. Muza ◽  
G. J. Criner ◽  
S. G. Kelsen
Keyword(s):  
Electrical Stimulation ◽  
Lung Volume ◽  
Intrathoracic Pressure ◽  
Pectoral Muscle ◽  
Positive Pressure ◽  
Rib Cage ◽  
Mechanical Coupling ◽  
Negative Intrathoracic Pressure ◽  
Pressure Changes ◽  
Stimulation Of

Lung volume influences the mechanical action of the primary inspiratory and expiratory muscles by affecting their precontraction length, alignment with the rib cage, and mechanical coupling to agonistic and antagonistic muscles. We have previously shown that the canine pectoral muscles exert an expiratory action on the rib cage when the forelimbs are at the torso's side and an inspiratory action when the forelimbs are held elevated. To determine the effect of lung volume on intrathoracic pressure changes produced by the canine pectoral muscles, we performed isolated bilateral supramaximal electrical stimulation of the deep pectoral and superficial pectoralis (descending and transverse heads) muscles in 15 adult supine anesthetized dogs during hyperventilation-induced apnea. Lung volume was altered by application of a negative or positive pressure (+/- 30 cmH2O) to the airway. In all animals, selective electrical stimulation of the descending, transverse, and deep pectoral muscles with the forelimbs held elevated produced negative intrathoracic pressure changes (i.e., an inspiratory action). Moreover, with the forelimbs elevated, increasing lung volume decreased both pectoral muscle fiber precontraction length and the negative intrathoracic pressure changes generated by contraction of each of these muscles. Conversely, with the forelimbs along the torso, increasing lung volume lengthened pectoral muscle precontraction length and augmented the positive intrathoracic pressure changes produced by muscle contraction (i.e., an expiratory action). These results indicate that lung volume significantly affects the length of the canine pectoral muscles and their mechanical actions on the rib cage.

The two mechanisms of intercostal muscle action on the lung

2004 ◽  
Vol 96 (2) ◽  
pp. 483-488 ◽  
Author(s):  
Theodore A. Wilson ◽  
Andre De Troyer
Keyword(s):  
Three Dimensional ◽  
Intercostal Muscle ◽  
Muscle Action ◽  
Opening Pressure ◽  
Rib Cage ◽  
Intercostal Muscles ◽  
Airway Opening ◽  
The Difference ◽  
External Forces

The mechanisms of respiratory action of the intercostal muscles were studied by measuring the effect of external forces (F) applied to the ribs and by modeling the effect of F exerted by the intercostal muscles. In five dogs, with the airway occluded, cranial F were applied to individual rib pairs, from the 2nd to the 11th rib pair, and the change in airway opening pressure (Pao) was measured. The ratio Pao/F increases with increasing rib number in the upper ribs (2nd to 5th) and decreases in the lower ribs (5th to 11th). These data were incorporated into a model for the geometry of the ribs and intercostal muscles, and Pao/F was calculated from the model. For interspaces 2-8, the calculated values agree reasonably well with previously measured values. From the modeling, two mechanisms of intercostal muscle action are identified. One is the well-known Hamberger mechanism, modified to account for the three-dimensional geometry of the rib cage. This mechanism depends on the slant of an intercostal muscle relative to the ribs and on the resulting difference between the moments applied to the upper and lower ribs that bound each interspace. The second is a new mechanism that depends on the difference between the values of Pao/F for the upper and lower ribs.

An analysis of action of intercostal muscles in human upper rib cage

1986 ◽  
Vol 60 (2) ◽  
pp. 690-701 ◽  
Author(s):  
R. C. Saumarez
Keyword(s):  
Mathematical Model ◽  
Vertebral Column ◽  
Erector Spinae ◽  
Intercostal Muscle ◽  
Paraspinal Muscles ◽  
Rib Cage ◽  
Intercostal Muscles ◽  
Physiological Load ◽  
Deep Layers ◽  
Made In

The actions of the intercostal and paraspinal muscles in stabilizing the human upper rib cage have been analyzed using a geometrically realistic mathematical model of the first six ribs, vertebrae, and associated musculature. The model suggests roles of the deep layers of erector spinae in stabilizing the vertebral column so that it can support the loads placed upon it by the ribs under physiological load. If we assume that the tension exerted by an intercostal muscle is proportional to its local thickness, the model predicts that the observed distribution of intercostal thickness is close to that which minimizes the stresses in ribs when the model is subjected to peak physiological load. The observed shape of the ribs are optimal to withstand the calculated pattern of loading along their length. These calculations raise the hypothesis that the arrangement of intercostal musculature and rib geometry result in an optimally light rib cage, which is capable of withstanding the loads placed upon it. The analysis of the mechanics of the entire model indicates that the geometrical simplifications made in Hamberger's model are not valid when applied to the rib cage.

Patterns of intercostal muscle activity in humans

1989 ◽  
Vol 67 (5) ◽  
pp. 2087-2094 ◽  
Author(s):  
W. A. Whitelaw ◽  
T. Feroah
Keyword(s):  
Human Subjects ◽  
Emg Activity ◽  
Deep Breathing ◽  
Flow Volume ◽  
Intercostal Muscle ◽  
Rib Cage ◽  
Intercostal Muscles ◽  
Fine Wire ◽  
Midaxillary Line ◽  
Emg Electrodes

Coordination of activity of inspiratory intercostal muscles in conscious human subjects was studied by means of an array of electromyograph (EMG) electrodes. Bipolar fine wire electrodes were placed in the second and fourth parasternal intercostal muscles and in two or three external intercostal muscles in the midaxillary line from the fourth to eighth intercostal spaces. Subjects breathed quietly or rebreathed from a bag containing 8% CO2 in O2 in both supine and upright postures. Respiration was monitored by means of flow, volume, and separate rib cage and abdominal volumes. Onset of EMG activity in each breath was found near the beginning of inspiration in the uppermost intercostal spaces but progressively later in inspiration in lower spaces, indicating that activity spreads downward across the rib cage through inspiration. At higher ventilation stimulated by CO2, activity spread further and faster downward. In voluntary deep breathing, external intercostal muscles tended to be recruited earlier in inspiration than in CO2-stimulated breathing. The change from supine to sitting resulted in small and inconsistent changes. There was no lung volume or rib cage volume threshold for appearance of EMG activity in any of the spaces.

Action of abdominal muscles on rib cage in humans

1985 ◽  
Vol 58 (5) ◽  
pp. 1438-1443 ◽  
Author(s):  
A. Mier ◽  
C. Brophy ◽  
M. Estenne ◽  
J. Moxham ◽  
M. Green ◽  
...  
Keyword(s):  
Rectus Abdominis ◽  
Abdominal Muscles ◽  
Transverse Diameter ◽  
Transdiaphragmatic Pressure ◽  
Rib Cage ◽  
X Ray ◽  
Surface Electrodes ◽  
Residual Capacity ◽  
External Oblique ◽  
Stimulation Of

To assess the actions of the rectus abdominis and external oblique muscles on the rib cage in humans, these two muscles were stimulated with surface electrodes in four normal supine subjects at functional residual capacity. Changes in anteroposterior and transverse rib cage diameters and changes in xiphipubic distance were measured with pairs of magnetometers. Stimulation of rectus abdominis produced a marked decrease in the xiphipubic distance and in the anteroposterior diameter, thus making the rib cage more elliptic. In contrast, stimulation of the external oblique caused a decrease in the transverse diameter, making the rib cage more cylindrical. When both muscles were stimulated simultaneously, the resultant rib cage distortion depended on the relative voltage at which each muscle was stimulated. Electromyogram recordings showed that there was no cross contamination or activity of the diaphragm during the muscle stimulations. Transdiaphragmatic pressure increased with the voltage of stimulation, suggesting passive lengthening of the diaphragm. X-ray studies were performed in two subjects and confirmed the main magnetometer findings. These studies thus confirm that the rib cage in humans is more easily distortable than conventionally thought. The abdominal muscles can distort it in either direction depending on which muscles are contracting.

Effects of abdominal opening on respiratory system mechanics in ventilated rats

1989 ◽  
Vol 66 (6) ◽  
pp. 2496-2501 ◽  
Author(s):  
W. A. Zin ◽  
M. A. Martins ◽  
P. R. Silva ◽  
R. S. Sakae ◽  
A. L. Carvalho ◽  
...  
Keyword(s):  
Respiratory System ◽  
Lung Volume ◽  
Open Abdomen ◽  
Rib Cage ◽  
Mechanically Ventilated ◽  
Respiratory System Mechanics ◽  
Before And After ◽  
Residual Capacity ◽  
The Difference ◽  
Lateral Diameter

In 16 anesthetized paralyzed mechanically ventilated rats, respiratory system mechanics and rib cage dimensions were determined both before and after wide abdominal opening. In eight animals the end-inflation occlusion method disclosed statistically significant postoperative increases in respiratory system elastance (from 4.84 to 6.49 cmH2O.ml-1) and resistance (from 0.224 to 0.300 cmH2O.ml-1.s); the latter resulted from a rise of its uneven component (from 0.161 to 0.209 cmH2O.ml-1.s). In the remaining rats, rib cage morphometry at functional residual capacity after surgery showed significant decreases in lower rib cage circumference and anteroposterior and lateral diameters, whereas there was an increase in upper rib cage circumference and a fall in its lateral diameter. When these parameters were measured at end-inspiratory lung volume, the difference between intact and open abdomen were less striking; only lower rib cage circumference and upper rib cage lateral diameter significantly decreased postoperatively. Because surgery induced an expiratory volume of only 0.1 ml, it can be concluded that abdominal opening redistributed regional volumes within the lung, leading to increased unevenness in the system.

Mechanical arrangement of costal and crural diaphragms in dogs

1984 ◽  
Vol 56 (6) ◽  
pp. 1484-1490 ◽  
Author(s):  
M. Decramer ◽  
A. De Troyer ◽  
S. Kelly ◽  
P. T. Macklem
Keyword(s):  
Lung Volume ◽  
Quiet Breathing ◽  
Transdiaphragmatic Pressure ◽  
Length Relationship ◽  
Residual Capacity ◽  
In Series ◽  
Anesthetized Dogs ◽  
The Relationship ◽  
Mechanical Arrangement ◽  
Stimulation Of

To assess the mechanical arrangement of the costal and crural parts of the diaphragm, we studied changes in diaphragmatic length with piezoelectric crystals in 17 supine anesthetized dogs. During control resting inspiration, the crural part usually shortened more and earlier than the costal part. After phrenicotomy, the crural part always lengthened during inspiration, whereas the costal part shortened or lengthened. These interanimal differences disappeared after opening of the abdomen; the costal part then always lengthened during inspiration. During stimulation of one part, the relaxed nonstimulated part always lengthened. However, when compared with the relationship between length and transdiaphragmatic pressure (Pdi) obtained during passive deflation, the lengthening of the relaxed part during stimulation of either part was small. This difference between predicted and measured Pdi-length relationship decreased in magnitude as lung volume increased above functional residual capacity (FRC) and increased as residual volume was approached. These results indicate that 1) even during quiet breathing the diaphragm in the dog is not a single functional entity; 2) at FRC the costal and crural portions of the diaphragm behave as if they were mechanically arranged partly in parallel and partly in series; and 3) they gradually move into a pure mechanical series arrangement as lung volume increases.

scholarly journals Effect of intercostal muscle contraction on rib motion in humans studied by finite element analysis

2018 ◽  
Vol 125 (4) ◽  
pp. 1165-1170 ◽  
Author(s):  
Guangzhi Zhang ◽  
Xian Chen ◽  
Junji Ohgi ◽  
Fei Jiang ◽  
Seiryo Sugiura ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Muscle Contraction ◽  
Muscle Force ◽  
Special Structure ◽  
Tissue Deformation ◽  
Intercostal Muscle ◽  
Element Analysis ◽  
Rib Cage ◽  
Intercostal Muscles

The effect of intercostal muscle contraction on generating rib motion has been investigated for a long time and is still controversial in physiology. This may be because of the complicated structure of the rib cage, making direct prediction of the relationship between intercostal muscle force and rib movement impossible. Finite element analysis is a useful tool that is good at solving complex structural mechanic problems. In this study, we individually activated the intercostal muscle groups from the dorsal to ventral portions and obtained five different rib motions classified based on rib moving directions. We found that the ribs cannot only rigidly rotate around the spinal joint but also be deformed, particularly around the relatively soft costal cartilages, where the moment of muscle force for the rigid rotation is small. Although the intercostal muscles near the costal cartilages cannot generate a large moment to rotate the ribs, the muscles may still have a potential to deform the costal cartilages and contribute to the expansion and contraction of the rib cage based on the force-length relationship. Our results also indicated that this potential is matched well with the special shape of the costal cartilages, which become progressively oblique in the caudal direction. Compared with the traditional explanation of rib motion, by additionally considering the effect from the tissue deformation, we found that the special structure of the ventral portion of the human rib cage could be of mechanical benefit to the intercostal muscles, generating inspiratory and expiratory rib motions. NEW & NOTEWORTHY Compared with the traditional explanation of rib motion, additionally considering the effect from tissue deformation helps us understand the special structure of the ventral portion of the human rib cage, such that the costal cartilages progressively become oblique and the costochondral junction angles gradually change into nearly right angles from the upper to lower ribs, which could be of mechanical benefit to the intercostal muscles in the ventral portion, generating inspiratory and expiratory rib motions.

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