41. This duct is formed when the ectoderm thickens into a cord and sinks into the underlying mesenchyme. 42. Expression in the head ectoderm will give rise to the nasal placodes and to the eye placodes. 43. A transplanted blastopore lip can convert ectoderm into neural tissue and is said to have an inductive effect. 44. These three " germ layers " are known as the ectoderm , mesoderm, and endoderm. 45. Now, as the ectoderm continues to elongate, the ectodermal cells of the neural plate fold inward. 46. The mesoderm forms at the same time as the other two germ layers, the ectoderm and endoderm. 47. Inhibition of BMPs allows neuroectoderm to arise from ectoderm , a process which eventually forms the neural plate. 48. Unlike the fore-and hindgut, which are derived from ectoderm , it has no cuticular lining. 49. Wnt6 is expressed by the overlying ectoderm and promotes the production of Paraxis, which facilitates the transition. 50. The ectoderm eventually forms the skin ( including hair and nails ), mucous membranes and nervous system.
