Whereas bolus transport along the esophagus results from peristaltic contractions of the circular muscle layer, it has been suggested that local shortening of the longitudinal muscle layer concentrates circular muscle fibers in the region where the highest contractile pressures are required. Here we analyze the mechanical consequences of local longitudinal shortening (LLS) through a mathematical model based on lubrication theory. We find that local pressure and shear stress in the contraction zone are greatly reduced by the existence of LLS. In consequence, peak contractile pressure is reduced by nearly 2/3 at physiological LLS, and this reduction is greatest when peak in LLS is well aligned with peak contractile pressure. We conclude that a peristaltic wave of local longitudinal muscle contraction coordinated with the circular muscle contraction wave has both a great physiological advantage (concentrating circular muscle fibers), and a great mechanical advantage (reducing the level of contractile force required to transport the bolus), which combine to greatly reduce circular muscle tone during esophageal peristalsis.
The Mechanical Advantage of Local Longitudinal Shortening on Peristaltic Transport
Contributed by the Bioengineering Division for the publication in the JOURNAL OF BIOMECHANICAL ENGINEERING. Manuscript received by the Bioengineering Division February 16, 2001; revision received September 24, 2001. Associate Editor: J. B. Grotberg.
- Views Icon Views
- Share Icon Share
- Cite Icon Cite
- Search Site
Pal , A., and Brasseur, J. G. (September 24, 2001). "The Mechanical Advantage of Local Longitudinal Shortening on Peristaltic Transport ." ASME. J Biomech Eng. February 2002; 124(1): 94–100. https://doi.org/10.1115/1.1427700
Download citation file:
- Ris (Zotero)
- Reference Manager