we examined the mechanical activity of the longitudinal and circular muscles of the esophagus at three different levels ( 9 , 5 , and 1 cm above the lower esophageal sphincter ) during peristalsis induced by swallows or vagal stimulation in anesthetized opossums with miniature strain gauges applied in the axis of muscle fibers .
C0014876
esophagus
C0227192
lower