11. The heart derives from splanchnopleuric mesenchyme in the neural plate which forms the cardiogenic region. 12. Each of these is surrounded by mesenchyme . 13. From splanchnopleuric mesenchyme , the cardiogenic region develops cranially and laterally to the neural plate. 14. Several different cells from the mesenchyme can give rise to sex-cord or stromal tumors. 15. In some colonial cnidarians, the mesenchyme is perforated by gastrovascular channels continuous among colony members. 16. Twist, a bHLH transcription factor, is required for mesenchyme differentiation of the pharyngeal arch structures. 17. It is suggested pericytes and smooth muscle cells come from neural crest cells and the surrounding mesenchyme . 18. Once in the blastocoel, the mesenchyme cells extend and contract long, thin processes called filopodia. 19. This duct is formed when the ectoderm thickens into a cord and sinks into the underlying mesenchyme . 20. First the epithelium signals the mesenchyme , then the mesenchyme induces the epithelial sheet to bud into it.
