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Human respiratory muscle actions and control during exercise.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Aliverti, Andrea Cala, Stephen J. Duranti, Roberto Ferrigno, Giancarlo Kenyon, Chris M. Pedotti, Antonio Scano, Giuseppina Sliwinski, Pawel Macklem, Peter T. Yan, Shao-Lin |
| Copyright Year | 1997 |
| Abstract | We measured pressures and power of diaphragm, rib cage, and abdominal muscles during quiet breathing (QB) and exercise at 0, 30, 50, and 70% maximum workload (Wmax) in five men. By three-dimensional tracking of 86 chest wall markers, we calculated the volumes of lung- and diaphragm-apposed rib cage compartments (Vrc,p and Vrc,a, respectively) and the abdomen (Vab). End-inspiratory lung volume increased with percentage of Wmax as a result of an increase in Vrc,p and Vrc,a. End-expiratory lung volume decreased as a result of a decrease in Vab. DeltaVrc,a/DeltaVab was constant and independent of Wmax. Thus we used DeltaVab/time as an index of diaphragm velocity of shortening. From QB to 70% Wmax, diaphragmatic pressure (Pdi) increased approximately 2-fold, diaphragm velocity of shortening 6.5-fold, and diaphragm workload 13-fold. Abdominal muscle pressure was approximately 0 during QB but was equal to and 180 degrees out of phase with rib cage muscle pressure at all percent Wmax. Rib cage muscle pressure and abdominal muscle pressure were greater than Pdi, but the ratios of these pressures were constant. There was a gradual inspiratory relaxation of abdominal muscles, causing abdominal pressure to fall, which minimized Pdi and decreased the expiratory action of the abdominal muscles on Vrc,a gradually, minimizing rib cage distortions. We conclude that from QB to 0% Wmax there is a switch in respiratory muscle control, with immediate recruitment of rib cage and abdominal muscles. Thereafter, a simple mechanism that increases drive equally to all three muscle groups, with drive to abdominal and rib cage muscles 180 degrees out of phase, allows the diaphragm to contract quasi-isotonically and act as a flow generator, while rib cage and abdominal muscles develop the pressures to displace the rib cage and abdomen, respectively. This acts to equalize the pressures acting on both rib cage compartments, minimizing rib cage distortion. |
| Starting Page | 021111 |
| Ending Page | 021111 |
| Page Count | 1 |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://jap.physiology.org/content/jap/83/4/1256.full.pdf |
| PubMed reference number | 9338435v1 |
| Volume Number | 83 |
| Issue Number | 4 |
| Journal | Journal of applied physiology |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Abdominal Muscles Anatomical compartments Aortic Aneurysm, Abdominal Apnea Bone structure of rib Centimeters of Water Cervical Rib Syndrome Chest wall structure Coefficient Costello syndrome (disorder) Elfacos OW 100 Equivalent Weight Expiration, function Inspiration function Linear IgA Bullous Dermatosis Majewski Syndrome Muscle Muscle Contraction Respiratory Insufficiency Respiratory Muscles Rib Cage Rib Fractures Status Epilepticus Structure of parenchyma of lung Tension Triangular Septal Nucleus deflate - CompressionAlgorithm |
| Content Type | Text |
| Resource Type | Article |
