1. Cells in the area around the dorsal lip of the blastopore where mesoderm and ectoderm undergo a process of separation. 2. That part of the mesenchyme derived from ectoderm, especially from the neural crest in the cephalic region in very young embryos. SYN: ectomesenchyme. [mes- + ectoderm]
* * *
mes·ec·to·derm .mez-'ek-tə-.dərm, .mēz-, .mēs-, .mes- n the part of the mesenchyme derived from ectoderm esp. of the neural crest that gives rise to pigment cells, the meninges, and most of the branchial cartilages
* * *
mes·ec·to·derm (mez-ekґto-dərm) embryonic migratory cells, derived from the neural crest of the head, that contribute to the formation of the meninges and become pigment cells.Medical dictionary. 2011.