Respiratory and postural changes in intercostal muscle length in supine dogs

1986 ◽  
Vol 60 (5) ◽  
pp. 1686-1691 ◽  
Author(s):  
M. Decramer ◽  
S. Kelly ◽  
A. De Troyer
Keyword(s):  
Fiber Orientation ◽  
Spontaneous Breathing ◽  
Physiological Function ◽  
Muscle Length ◽  
Intercostal Muscle ◽  
Intercostal Muscles ◽  
Passive Rotation ◽  
Postural Changes ◽  
Anesthetized Dogs ◽  
Antagonistic Muscles

In an attempt to assess the physiological function(s) of the external (E) and internal interosseous (I) intercostal muscles, we measured the changes in intercostal muscle length during spontaneous breathing, during passive inflation, and during passive rotation of the trunk. Studies were performed on 46 muscles from 16 supine anesthetized dogs, and changes in muscle length were assessed by sonomicrometry. The changes were small during spontaneous breathing, whether before or after bilateral phrenicotomy, and the pattern was variable among animals and among interspaces. The E, however, particularly in the lower interspaces, often lengthened with inspiration, and the I, in particular in the upper interspaces, often shortened with inspiration. Only occasionally did the E and I in one interspace change in length in opposing directions. This was also true during passive inflation, where both E and I usually shortened in the upper interspaces and lengthened in the lower interspaces. By contrast, during passive rotation of the trunk, the E and I systematically changed in length in opposing directions, and either muscle could successively lengthen and shorten a substantial amount depending on the side of rotation. These results suggest that 1) the E and I in supine dogs do not behave as antagonistic muscles during moderate respiratory efforts; and 2) they do behave as antagonistic muscles during rotation of the trunk. A primary function of these muscles as rotators of the trunk, unlike breathing, may explain why two layers of intercostal muscles with different fiber orientation exist between the ribs.

Respiratory changes in thoracic muscle length during bronchoconstriction

1987 ◽  
Vol 63 (1) ◽  
pp. 221-228 ◽  
Author(s):  
E. van Lunteren ◽  
M. A. Haxhiu ◽  
E. C. Deal ◽  
J. S. Arnold ◽  
N. S. Cherniack
Keyword(s):  
Tidal Volume ◽  
Respiratory Muscle ◽  
Muscle Length ◽  
Emg Activity ◽  
Intercostal Muscle ◽  
Mean Velocity ◽  
Intercostal Muscles ◽  
Fine Wire ◽  
Velocity Of Shortening ◽  
The Mean

The purpose of the present study was to assess the effects of bronchoconstriction on respiratory changes in length of the costal diaphragm and the parasternal intercostal muscles. Ten dogs were anesthetized with pentobarbital sodium and tracheostomized. Respiratory changes in muscle length were measured using sonomicrometry, and electromyograms were recorded with bipolar fine-wire electrodes. Administration of histamine aerosols increased pulmonary resistance from 6.4 to 14.5 cmH2O X l–1 X s, caused reductions in inspiratory and expiratory times, and decreased tidal volume. The peak and rate of rise of respiratory muscle electromyogram (EMG) activity increased significantly after histamine administration. Despite these increases, bronchoconstriction reduced diaphragm inspiratory shortening in 9 of 10 dogs and reduced intercostal muscle inspiratory shortening in 7 of 10 animals. The decreases in respiratory muscle tidal shortening were less than the reductions in tidal volume. The mean velocity of diaphragm and intercostal muscle inspiratory shortening increased after histamine administration but to a smaller extent than the rate of rise of EMG activity. This resulted in significant reductions in the ratio of respiratory muscle velocity of shortening to the rate of rise of EMG activity after bronchoconstriction for both the costal diaphragm and the parasternal intercostal muscles. Bronchoconstriction changed muscle end-expiratory length in most animals, but for the group of animals this was statistically significant only for the diaphragm. These results suggest that impairments of diaphragm and parasternal intercostal inspiratory shortening occur after bronchoconstriction; the mechanisms involved include an increased load, a shortening of inspiratory time, and for the diaphragm possibly a reduction in resting length.

Parasternal and external intercostal responses to various respiratory maneuvers

1992 ◽  
Vol 73 (3) ◽  
pp. 979-986 ◽  
Author(s):  
A. F. DiMarco ◽  
J. R. Romaniuk ◽  
G. S. Supinski
Keyword(s):  
Muscle Length ◽  
Similar Degree ◽  
Intercostal Muscle ◽  
Abdominal Compression ◽  
Similar Extent ◽  
Rib Cage ◽  
Piezoelectric Crystals ◽  
Intercostal Muscles ◽  
Steel Electrodes

Recent studies suggest that the external intercostal (EI) muscles of the upper rib cage, like the parasternals (PA), play an important ventilatory role, even during eupneic breathing. The purpose of the present study was to further assess the ventilatory role of the EI muscles by determining their response to various static and dynamic respiratory maneuvers and comparing them with the better-studied PA muscles. Applied interventions included 1) passive inflation and deflation, 2) abdominal compression, 3) progressive hypercapnia, and 4) response to bilateral cervical phrenicotomy. Studies were performed in 11 mongrel dogs. Electromyographic (EMG) activities were monitored via bipolar stainless steel electrodes. Muscle length (percentage of resting length) was monitored with piezoelectric crystals. With passive rib cage inflation produced either with a volume syringe or abdominal compression, each muscle shortened; with passive deflation, each muscle lengthened. During eupneic breathing, each muscle was electrically active and shortened to a similar degree. In response to progressive hypercapnia, peak EMG of each intercostal muscle increased linearly and to a similar extent. Inspiratory shortening also increased progressively with increasing PCO2, but in a curvilinear fashion with no significant differences in response among intercostal muscles. In response to phrenicotomy, the EMG and degree of inspiratory shortening of each intercostal muscle increased significantly. Again, the response among intercostal muscles was not significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)

Respiratory function of intercostal muscles in supine dog: an electromyographic study

1986 ◽  
Vol 60 (5) ◽  
pp. 1692-1699 ◽  
Author(s):  
A. De Troyer ◽  
V. Ninane
Keyword(s):  
Respiratory Function ◽  
Traditional View ◽  
Lower Portion ◽  
Intercostal Muscle ◽  
Muscle Action ◽  
Quiet Breathing ◽  
Rib Cage ◽  
Intercostal Muscles ◽  
Anesthetized Dogs ◽  
The Difference

It is traditionally considered that the difference in orientation of the muscle fibers makes the external intercostals elevate the ribs and the internal interosseous intercostals lower the ribs during breathing. This traditional view, however, has recently been challenged by the observation that the external and internal interosseous intercostals, when contracting alone in a single interspace, have a similar effect on the ribs into which they insert. This view has also been challenged by the observation that the external and internal intercostals in a given interspace often change their length in the same direction during breathing. In an attempt to clarify the respiratory function of these muscles, we studied eight supine lightly anesthetized dogs during quiet breathing and during static inspiratory efforts. In each animal electromyographic (EMG) recordings from the external and internal interosseous intercostals were obtained in all interspaces from the second to the eighth, and selective denervations were systematically performed to ensure with complete certainty the origin of the recorded EMG activities. The external intercostals were only activated in phase with inspiration, whereas the internal interosseous intercostals were only activated in phase with expiration. These phasic EMG activities, however, were generally small in magnitude, and the muscles were often silent. Indeed, activation of the externals was always confined to the upper portion of the rib cage, whereas activation of the internals was limited to the lower portion of the rib cage. Internal intercostal activation always occurred sequentially along a caudocephalic gradient. These observations are thus compatible with the traditional view of intercostal muscle action.(ABSTRACT TRUNCATED AT 250 WORDS)

Respiratory muscle length measured by sonomicrometry

1984 ◽  
Vol 56 (3) ◽  
pp. 753-764 ◽  
Author(s):  
S. Newman ◽  
J. Road ◽  
F. Bellemare ◽  
J. P. Clozel ◽  
C. M. Lavigne ◽  
...  
Keyword(s):  
Spontaneous Breathing ◽  
Muscle Length ◽  
Length Change ◽  
Lung Inflation ◽  
Velocity Of Shortening ◽  
Anesthetized Dogs ◽  
Supramaximal Stimulation ◽  
Irreversible Injury ◽  
Anatomical Part

The use of sonomicrometry to study the mechanical properties of the diaphragm in vivo is presented. This method consists of the implantation of piezoelectric transducers between muscle fibers to measure the fibers' changes in length. Ultrasonic bursts are produced by one transducer upon electrical excitation and sensed by a second transducer placed 1–2 cm away. The time elapsed between the generation of the ultrasound burst and its detection is used to calculate the intertransducer distance. Excitation and sampling are done at 1.5 kHz and the output is a DC signal proportional to the length change between the transducers. Neither irreversible injury to the diaphragm nor regional differences within an anatomical part or segment were noted. Measurements were stable within the physiological range of temperature. We measured costal and crural length and velocity of contraction in anesthetized dogs during spontaneous breathing, occluded inspirations, passive lung inflation, and supramaximal phrenic nerve stimulation. We found that shortening during spontaneous breathing was 11 and 6% for crural and costal, respectively. The crural leads the costal in velocity of shortening. Supramaximal stimulation results in a velocity of shortening of 5 resting lengths X s-1. During an occluded inspiration crural shortens as much as in the nonoccluded breath, whereas costal shortens less. During passive lung inflation there is a nearly linear relationship between lung volume and diaphragm length; however, the relationships of chest wall dimensions with diaphragm length are nonlinear and cannot be described by any simple function. Some of the implications of these data on the present understanding of diaphragmatic mechanics are discussed.

Parasternal and external intercostal muscle shortening during eupneic breathing

1990 ◽  
Vol 69 (6) ◽  
pp. 2222-2226 ◽  
Author(s):  
A. F. DiMarco ◽  
J. R. Romaniuk ◽  
G. S. Supinski
Keyword(s):  
Muscle Contraction ◽  
Muscle Length ◽  
Intercostal Muscle ◽  
Muscle Denervation ◽  
Similar Extent ◽  
Rib Cage ◽  
The Third ◽  
Muscle Shortening ◽  
Anesthetized Dogs ◽  
Mechanical Consequence

The interosseous external intercostal (EI) muscles of the upper rib cage are electrically active during inspiration, but the mechanical consequence of their activation is unclear. In 16 anesthetized dogs, we simultaneously measured EI (3rd and 4th interspaces) and parasternal intercostal (PA) (3rd interspace) electromyogram and length. Muscle length was measured by sonomicrometry and expressed as a percentage of resting length (%LR). During resting breathing, each muscle was electrically active and shortened to a similar extent. Sequential EI muscle denervation (3rd and 4th interspaces) followed by PA denervation (3rd interspace) demonstrated significant reductions in the degree of inspiratory shortening for each muscle. Mean EI muscle shortening of the third and fourth interspaces decreased from -3.4 +/- 0.5 and -3.0 +/- 0.4% LR (SE) under control conditions to -0.2 +/- 0.2 and -0.8 +/- 0.3% LR, respectively, after selective denervation of each of these muscles (P less than 0.001 for each). After selective denervation of the PA muscle, its shortening decreased from -3.5 +/- 0.3 to +0.6% LR (SE) (P less than 0.001). PA muscle denervation also caused the EI muscle in the third interspace to change from inspiratory shortening of -0.2% to inspiratory lengthening of +0.2% +/- 0.2 (P less than 0.05). We conclude that during eupneic breathing 1) the EI muscles of the upper rib cage, like the PA muscles, are inspiratory agonists and actively contribute to rib cage expansion and 2) PA muscle contraction contributes to EI muscle shortening.

scholarly journals Noninvasive Assessment of Neuromechanical Coupling and Mechanical Efficiency of Parasternal Intercostal Muscle during Inspiratory Threshold Loading

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1781
Author(s):  
Manuel Lozano-García ◽  
Luis Estrada-Petrocelli ◽  
Abel Torres ◽  
Gerrard F. Rafferty ◽  
John Moxham ◽  
...  
Keyword(s):  
Mechanical Efficiency ◽  
Intercostal Muscle ◽  
Wireless Devices ◽  
Clinical Value ◽  
Intercostal Muscles ◽  
Noninvasive Measurements ◽  
Standard Assessment ◽  
Mouth Pressure ◽  
Invasive Techniques ◽  
Increasing Load

This study aims to investigate noninvasive indices of neuromechanical coupling (NMC) and mechanical efficiency (MEff) of parasternal intercostal muscles. Gold standard assessment of diaphragm NMC requires using invasive techniques, limiting the utility of this procedure. Noninvasive NMC indices of parasternal intercostal muscles can be calculated using surface mechanomyography (sMMGpara) and electromyography (sEMGpara). However, the use of sMMGpara as an inspiratory muscle mechanical output measure, and the relationships between sMMGpara, sEMGpara, and simultaneous invasive and noninvasive pressure measurements have not previously been evaluated. sEMGpara, sMMGpara, and both invasive and noninvasive measurements of pressures were recorded in twelve healthy subjects during an inspiratory loading protocol. The ratios of sMMGpara to sEMGpara, which provided muscle-specific noninvasive NMC indices of parasternal intercostal muscles, showed nonsignificant changes with increasing load, since the relationships between sMMGpara and sEMGpara were linear (R2 = 0.85 (0.75–0.9)). The ratios of mouth pressure (Pmo) to sEMGpara and sMMGpara were also proposed as noninvasive indices of parasternal intercostal muscle NMC and MEff, respectively. These indices, similar to the analogous indices calculated using invasive transdiaphragmatic and esophageal pressures, showed nonsignificant changes during threshold loading, since the relationships between Pmo and both sEMGpara (R2 = 0.84 (0.77–0.93)) and sMMGpara (R2 = 0.89 (0.85–0.91)) were linear. The proposed noninvasive NMC and MEff indices of parasternal intercostal muscles may be of potential clinical value, particularly for the regular assessment of patients with disordered respiratory mechanics using noninvasive wearable and wireless devices.

Activity patterns in individual hindlimb primary and secondary muscle spindle afferents during normal movements in unrestrained cats

1979 ◽  
Vol 42 (2) ◽  
pp. 420-440 ◽  
Author(s):  
G. E. Loeb ◽  
J. Duysens
Keyword(s):  
Muscle Spindle ◽  
Activity Patterns ◽  
Muscle Length ◽  
Muscle Spindle Afferents ◽  
General Observation ◽  
Postural Changes ◽  
Motor Activities ◽  
Specific Muscle ◽  
Length Changes ◽  
Rapid Modulation

1. Chronically implanted microelectrode wires in the L7 and S1 dorsal root ganglia were used to record unit activity from cat hindlimb primary and secondary muscle spindle afferents. Units could be reliably recorded for several days, permitting comparison of their activity with homonymous muscle EMG and length during a variety of normal, unrestrained movements. 2. The general observation was that among both primary and secondary endings there was a broad range of different patterns of activity depending on the type of muscle involved and the type of movement performed. 3. During walking, the activity of a given spindle primary was usually consistent among similar step cycles. However, the activity was usually poorly correlated with absolute muscle length, apparently unrealted to velocity of muscle stretch, and could change markedly for similar movements performed under different conditions. 4. Spindle activity modulation not apparently related to muscle length changes was assumed to be influenced by fusimotor activity. In certain muscles, this presumption leads to the conclusion that gamma-motoneurons may be activated out of phase with homonymous alpha-motoneurons as well as by more conventional alpha-gamma-motoneuron coactivation. 5. Simultaneous recordings of two spindle primary afferents from extensor digitorum longus indicated that spindles within the same muscle may differ considerably with respect to this presumed gamma-motoneuron drive. 6. Spindle secondary endings appeared to be predominantly passive indicators of muscle length during walking, but could demonstrate apparently strong fusimotor modulation during other motor activities such as postural changes and paw shaking. 7. Both primary and secondary endings were observed to undergo very rapid modulation of firing rates in response to presumed reflexly induced intrafusal contractions. 8. It is suggested that the pattern of fusimotor control of spindles may be tailored to the specific muscle and task being performed, rather than necessarily dominated by rigid alpha-gamma coactivation.

Mechanical role of expiratory muscles during breathing in upright dogs

1988 ◽  
Vol 64 (3) ◽  
pp. 1060-1067 ◽  
Author(s):  
G. A. Farkas ◽  
R. E. Baer ◽  
M. Estenne ◽  
A. De Troyer
Keyword(s):  
Tidal Volume ◽  
Progressive Increase ◽  
Substantial Contribution ◽  
Postural Changes ◽  
Before And After ◽  
Cervical Vagotomy ◽  
Anesthetized Dogs ◽  
Expiratory Muscles ◽  
Spontaneously Breathing

To examine the mechanical effects of the abdominal and triangularis sterni expiratory recruitment that occurs when anesthetized dogs are tilted head up, we measured both before and after cervical vagotomy the end-expiratory length of the costal and crural diaphragmatic segments and the end-expiratory lung volume (FRC) in eight spontaneously breathing animals during postural changes from supine (0 degree) to 80 degrees head up. Tilting the animals from 0 degree to 80 degrees head up in both conditions was associated with a gradual decrease in end-expiratory costal and crural diaphragmatic length and with a progressive increase in FRC. All these changes, however, were considerably larger (P less than 0.005 or less) postvagotomy when the expiratory muscles were no longer recruited with tilting. Alterations in the elastic properties of the lung could not account for the effects of vagotomy on the postural changes. We conclude therefore that 1) by contracting during expiration, the canine expiratory muscles minimize the shortening of the diaphragm and the increase in FRC that the action of gravity would otherwise introduce, and 2) the end-expiratory diaphragmatic length and FRC in upright dogs are thus actively determined. The present data also indicate that by relaxing at end expiration, the expiratory muscles make a substantial contribution to tidal volume in upright dogs; in the 80 degrees head-up posture, this contribution would amount to approximately 60% of tidal volume.

beta-Endorphin central depression of respiration and circulation

1981 ◽  
Vol 50 (5) ◽  
pp. 1011-1016 ◽  
Author(s):  
I. R. Moss ◽  
E. M. Scarpelli
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cerebrospinal Fluid ◽  
Spontaneous Breathing ◽  
Respiratory Control ◽  
Maximal Effect ◽  
Occlusion Pressure ◽  
Beta Endorphin ◽  
Control Units ◽  
Anesthetized Dogs

Beta-Endorphin was injected into cerebrospinal fluid of lightly anesthetized dogs. Its effects on ventilation (V), tidal volume (VT), respiratory frequency (f), preinspiratory occlusion pressure (P500), and respiratory timing of unoccluded and occluded breaths were studied during CO2 rebreathing. Blood pressure and heart rate (HR) were monitored throughout the study. beta-Endorphin produced 1) early (approximately 15 min) but temporary depression of VT-PCO2 and P500-PCO2 responses; 2) progressive hypoventilation during spontaneous breathing and progressive depression of V-PCO2 and f-PCO2 responses, which were maximal at about 75 min, followed by gradual recovery; 3) progressive hypotension and bradycardia starting at about 15 min and reaching maximal effect at about 105 min. Increased expiratory time (TE) accounted for the changes in f. TE increased in unoccluded breaths and during both preinspiratory and inflation occlusion. After vagotomy, beta-endorphin produced insignificant effect on f, TE, and HR. Naloxone itself increased P500-PCO2 response; when given during beta-endorphin effect, it reversed the hypotension, bradycardia, V-PCO2, and f-PCO2 responses and facilitated the P500-PCO2 and VT-PCO2 responses. We conclude that beta-endorphin effect is produced by both depression of specific central cardiovascular and respiratory control units and facilitation of central vagal projections.

In vivo regional diaphragm function in dogs

1989 ◽  
Vol 67 (2) ◽  
pp. 655-662 ◽  
Author(s):  
J. Sprung ◽  
C. Deschamps ◽  
R. D. Hubmayr ◽  
B. J. Walters ◽  
J. R. Rodarte
Keyword(s):  
Mechanical Ventilation ◽  
Chest Wall ◽  
Spontaneous Breathing ◽  
Considerable Variability ◽  
Diaphragm Function ◽  
Left Hemidiaphragm ◽  
Anesthetized Dogs ◽  
Abdominal Surface ◽  
Crural Diaphragm

A biplane videofluorographic system was used to track the position of metallic markers affixed to the abdominal surface of the left hemidiaphragm in supine anesthetized dogs. Regional shortening was determined from intermarker distances of rows of markers placed along muscle bundles in the ventral, middle, and dorsal regions of the costal diaphragm and of one row on the crural diaphragm. Considerable variability of regional shortening was seen in a given row, which was reproducible on repeat study in individual dogs but which differed between mechanical ventilation and spontaneous breathing. There were no consistent patterns among dogs. Regional shortening obtained from the change in length of rows extending from chest wall to central tendon showed no consistent differences among dogs during spontaneous breathing. At equal tidal volumes, all regions (except the ventral costal diaphragm) shortened more during spontaneous breathing than during mechanical ventilation.

Sign in / Sign up

Export Citation Format

Share Document