Each arch has a pouch, membrane and cleft. Rathke's pouch eventually looses its connection with the pharynx. Connects centrally with the dorsal horn of the spinal cord. SHH function is different for different tissues in the embryo. In the nervous system, it is secreted by the notochord, ventralizes the neural tube, inducing the floor plate and motor neurons.
Neuroepithelial cells generate neurons, glia and ependymal cells.
These notes from the Embryology program compiled and written by Dr Mark Hill. PubMed Medline Entries are copies of originals for computers without internet access. Computers with internet access can directly access the database. Note that reference lists are only relevant to the date that the original search was carried out.