Fig. 6. Effects of myotomy on retrograde giant contraction (RGC). This figure depicts the effects of myotomy at 60 cm from the pylorus on the orientation and propagation of the RGC across the small intestine. Myotomy blocked occurrence of the RGC at J70, reduced the magnitude and duration of the RGC at J80, J90, and J100, and resulted in 2 separate RGC’s occurring above and below the myotomy propagating independently of each other. Myotomy had no observable effects orad of the myotomy. The control figure also provides an excellent example of the inhibition of motor activity for about 5 seconds before the RGC. The vertical lines in this figure are vertical reference lines so that direction and degree of propagation can be more easily assessed. The horizontal line in this figure depicts the location of the myotomy. P3, phase III of the migrating motor complex; A, antrum; D, duodenum; J, jejunum; I, ileum. The numbers after the letters indicate the cm from the pylorus of the strain gauge. Adapted from Lang.
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