Fig. 1. Angle of mouth and the soft palate. H&E staining. Panels (A–C) (a fetus of 310 mm; a single frontal section) display the angle of mouth. Panels (D–F) (a fetus of 328 mm; a single sagittal section) exhibit the soft palate. Panels (B, C) (or E, F) are higher magnification views of squares in panel (A) (or D, E). The platysma muscle (PM) joins the levator angli oris muscle (LAOM) and, at the meeting site, a fibrous tissue appears to connect these muscle fibers (B). The levator muscle crosses the depressor angli oris muscle (DAOM), but a crossing of a solitary-to-solitary muscle fiber is unlikely because the depressor muscle fibers are bundled (C). Likewise, in the soft palate (D), a solitary muscle fiber of the uveae muscle (UM) crosses a bundled fibers of the levator veli palatini muscle (LVPM). (A, C–E) Scale bars=1 mm, (B, F) scale bars=0.1 mm. OOM, orbicularis oris muscle; PB, palatine bone.
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