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Neuroectoderm (or neural ectoderm or neural tube epithelium) consists of cells derived from the ectoderm. Formation of the neuroectoderm is the first step in the development of the nervous system . [ 1 ]
Neuroepithelial cells of the ectoderm begin multiplying rapidly and fold in forming the neural plate, which invaginates during the fourth week of embryonic growth and forms the neural tube. [2] The formation of the neural tube polarizes the neuroepithelial cells by orienting the apical side of the cell to face inward, which later becomes the ...
In vertebrate embryos, the ectoderm can be divided into two parts: the dorsal surface ectoderm also known as the external ectoderm, and the neural plate, which invaginates to form the neural tube and neural crest. [4] The surface ectoderm gives rise to most epithelial tissues, and the neural plate gives rise to most neural tissues.
The neural tube develops in two ways: primary neurulation and secondary neurulation. Primary neurulation divides the ectoderm into three cell types: The internally located neural tube; The externally located epidermis; The neural crest cells, which develop in the region between the neural tube and epidermis but then migrate to new locations
The formation of the neural tube from the ectoderm is called neurulation. The ventral part of the neural tube is called the basal plate; the dorsal part is called the alar plate. The hollow interior is called the neural canal. By the end of the fourth week of gestation, the open ends of the neural tube, called the neuropores, close off. [5] A ...
The face and neck development of the human embryo refers to the development of the structures from the third to eighth week that give rise to the future head and neck.They consist of three layers, the ectoderm, mesoderm and endoderm, which form the mesenchyme (derived form the lateral plate mesoderm and paraxial mesoderm), neural crest and neural placodes (from the ectoderm). [1]
It forms the epithelial lining of the whole of the digestive tract except part of the mouth and pharynx and the terminal part of the rectum (which are lined by involutions of the ectoderm). It also forms the lining cells of all the glands which open into the digestive tract, including those of the liver and pancreas; the epithelium of the ...
Several layers such as the neural tube, neural crest, surface ectoderm, and mesoderm contribute to the development of the eye. [2] [3] [4] Eye development is initiated by the master control gene PAX6, a homeobox gene with known homologues in humans (aniridia), mice (small eye), and Drosophila (eyeless). The PAX6 gene locus is a transcription ...