Formation of an organ through the assembly of tissues of different kinds once the three germ layers (viz., ectoderm, entoderm, mesoderm) have been established. Many organs consist of cells from more than one germ layer. During organogenesis, some cells undergo long migrations to their final location from their place of origin. They include precursors of the blood cells, lymph cells, pigment cells and gametes. One example is cells migrating ventrally from the dorsal region of the head to form the facial bones. <\/p>\n
See Cell<\/a>, Cell migration<\/a>, Ectoderm<\/a>, Entoderm (or endoderm)<\/a>, Gametes<\/a>, Germinal (or germ) layers<\/a>, Growth<\/a>, Heterochrony<\/a>, Mesoderm<\/a>, Ontogenetic development<\/a>, Purines<\/a>, Systemogenesis<\/a><\/p>\n <\/body><\/html><\/p>\n","protected":false},"excerpt":{"rendered":" Formation of an organ through the assembly of tissues of different kinds once the three germ layers (viz., ectoderm, entoderm, mesoderm) have been established. Many organs consist of cells from more than one germ layer. During organogenesis, some cells undergo long migrations to their final location from their place of origin. They include precursors of … <\/p>\n