We summarize from previous works the functions of circular vs. longitudinal muscle in esophageal peristaltic bolus transport using a mix of experimental data, the conservation laws of mechanics and mathematical modeli...We summarize from previous works the functions of circular vs. longitudinal muscle in esophageal peristaltic bolus transport using a mix of experimental data, the conservation laws of mechanics and mathematical modeling. Whereas circular muscle tone generates radial closure pressure to create a local peristaltic closure wave, longitudinal muscle tone has two functions, one physiological with mechanical implications, and one purely mechanical. Each of these functions independently reduces the tension of individual circular muscle fibers to maintain closure as a consequence of shortening of longitudinal muscle locally coordinated with increasing circular muscle tone. The physiological function is deduced by combining basic laws of mechanics with concurrent measurements of intraluminal pressure from manometry, and changes in cross sectional muscle area from endoluminal ultrasound from which local longitudinal shortening (LLS) can be accurately obtained. The purely mechanical function of LLS was discovered from mathematical modeling of peristaltic esophageal transport with the axial wall motion generated by LLS. Physiologically, LLS concentrates circular muscle fibers where closure pressure is highest. However, the mechanical function of LLS is to reduce the level of pressure required to maintain closure. The combined physiological and mechanical consequences of LLS are to reduce circular muscle fiber tension and power by as much as 1/10 what would be requiredfor peristalsis without the longitudinal muscle layer, a tremendous benefit that may explain the existence of longitudinal muscle fiber in the gut. We also review what is understood of the role of longitudinal muscle in esophageal emptying, reflux and pathology.展开更多
Objective: To evaluate the effect of Shashen Maidong Decoction (SSMDD) on gastric motility.Method: Effect of SSMDD on the gastric motility of mice and rats was observed in vivo by administration of SSMDD in various do...Objective: To evaluate the effect of Shashen Maidong Decoction (SSMDD) on gastric motility.Method: Effect of SSMDD on the gastric motility of mice and rats was observed in vivo by administration of SSMDD in various dosages and observation on gastric phenol red excretion rate, gastric emptying rate, frequency and amplitude of contraction of fundic longitudinal muscles, etc. Results: SSMDD could reduce markedly the gastric phenol red excretion rate of mice, antagonize the acceleration of gastric emptying induced by neostigmine, inhibit the frequency and amplitude of contraction of fundic longitudinal muscle, slow down the frequency and decrease the amplitude of gastric peristalsis, and reduce the gastric hypermotility induced by indomethacin significantly. Conclusion: SSMDD has evident inhibition action on motility of experimental animals in vivo, its mechanism might be related with adrenergic nerve and metabolism of prostaglandin E.展开更多
文摘We summarize from previous works the functions of circular vs. longitudinal muscle in esophageal peristaltic bolus transport using a mix of experimental data, the conservation laws of mechanics and mathematical modeling. Whereas circular muscle tone generates radial closure pressure to create a local peristaltic closure wave, longitudinal muscle tone has two functions, one physiological with mechanical implications, and one purely mechanical. Each of these functions independently reduces the tension of individual circular muscle fibers to maintain closure as a consequence of shortening of longitudinal muscle locally coordinated with increasing circular muscle tone. The physiological function is deduced by combining basic laws of mechanics with concurrent measurements of intraluminal pressure from manometry, and changes in cross sectional muscle area from endoluminal ultrasound from which local longitudinal shortening (LLS) can be accurately obtained. The purely mechanical function of LLS was discovered from mathematical modeling of peristaltic esophageal transport with the axial wall motion generated by LLS. Physiologically, LLS concentrates circular muscle fibers where closure pressure is highest. However, the mechanical function of LLS is to reduce the level of pressure required to maintain closure. The combined physiological and mechanical consequences of LLS are to reduce circular muscle fiber tension and power by as much as 1/10 what would be requiredfor peristalsis without the longitudinal muscle layer, a tremendous benefit that may explain the existence of longitudinal muscle fiber in the gut. We also review what is understood of the role of longitudinal muscle in esophageal emptying, reflux and pathology.
文摘Objective: To evaluate the effect of Shashen Maidong Decoction (SSMDD) on gastric motility.Method: Effect of SSMDD on the gastric motility of mice and rats was observed in vivo by administration of SSMDD in various dosages and observation on gastric phenol red excretion rate, gastric emptying rate, frequency and amplitude of contraction of fundic longitudinal muscles, etc. Results: SSMDD could reduce markedly the gastric phenol red excretion rate of mice, antagonize the acceleration of gastric emptying induced by neostigmine, inhibit the frequency and amplitude of contraction of fundic longitudinal muscle, slow down the frequency and decrease the amplitude of gastric peristalsis, and reduce the gastric hypermotility induced by indomethacin significantly. Conclusion: SSMDD has evident inhibition action on motility of experimental animals in vivo, its mechanism might be related with adrenergic nerve and metabolism of prostaglandin E.
