Fig 2a. The muscularis externa (M) of the upper portion of the esophagus belongs to the skeletal muscle, appearing the inner circular and outer longitudinal arrangement patterns.

Fig 2b shows high-magnification of cross sectioned muscle cells, appearing the polygonal profiles. Notice the numerous of peripherally located multinuclei (N). Endomysium (E) is a layer of basal lamina, surrounding each individual muscle fibers.  Skeletal muscle