The neural tube is the embryonal structure that gives rise to the brain and spinal cord. The neural tube is derived from a thickened area of ectoderm, the neural plate. The process of formation of the neural tube is called neurulation. Embryos (and one tadpole) of the wrinkled frog (Rana rugosa). ... Comparative brain sizes In the anatomy of animals, the brain, or encephalon (Greek for in the head), is the higher, supervisory center of the nervous system. ... The spinal cord is a part of the vertebrate nervous system that is enclosed in and protected by the vertebral column (it passes through the spinal canal). ... It has been suggested that endoderm be merged into this article or section. ... The neural plate is thick and flat bundle of ectoderm which develops in the embryo into the nervous system. ... Neurulation is a morphogenetic process in the embryonic development of the vertebrates, by which the neural plate folds into the neural tube. ...

Development

Portions of the neural tube form by two different processes, called primary and secondary neurulation. In primary neurulation, the neural plate creases inward until the edges come in contact and fuse. In secondary neurulation, the tube forms by hollowing out of the interior of a solid precursor. Different amounts of the neural tube form by each means in different species.

Primary neurulation occurs in response to soluble growth factors secreted by the notochord. After Shh from the notocord induces its formation, the floor plate of the incipient neural tube also secretes Shh. After closure, the neural tube forms a basal plate and an alar plate in response to the combined effects of Shh and factors including bone morphogenic protein 4 secreted by the roof plate. The basal plate forms most of the ventral portion of the nervous system, including the motor portion of the spinal cord and brain stem; the alar plate forms the dorsal portions, devoted mostly to sensory processing. Growth factor is a protein that acts as a signaling molecule between cells (like cytokines and hormones) that attaches to specific receptors on the surface of a target cell and promotes differentiation and maturation of these cells. ... The notochord is a flexible rod-shaped body found in embryos of all chordates. ...

Neural tube defects

Normally the closure of the neural tube occurs around the 30th day after fertilization. However, if something interferes and the tube fails to close properly, a neural tube defect will occur. Among the most common tube defects are anencephaly, encephalocele, and spina bifida. The incidence of neural tube defects is 2.6 in 1,000 worldwide. Categories: Biology stubs ... The neural tube is the embryonal structure that gives rise to the brain and spinal cord. ... Cephalic disorders are congenital conditions that stem from damage to, or abnormal development of, the budding nervous system. ... In optics one considers angles of incidence. ...

Pregnant women taking medication for epilepsy have a higher chance of having a child with a neural tube defect. Research has shown that women with folic acid deficiences also have a higher chance of having a child with a neural tube defect, but this is only one factor. Taking folic acid does not completely negate the risk of neural tube problems, but markedly reduces the risk. Pregnancy Pregnancy is the carrying of one or more embryos or foeti by female mammals, including humans, inside their bodies. ... This article needs to be cleaned up to conform to a higher standard of quality. ...