Neural Tube Defects
Closure of the neural tube occurs in the middle, and then moves anteriorly and posteriorly. Failure to close the neural tube anteriorly results in anencephaly, a condition characterised by forebrain and skull degeneration, which is always fatal. Failure to close the posterior tube is known as spina bifida, which in its most severe form is characterised by failure to form the neural plate (bifida is derived from Latin, to mean 'cleft in two parts'). Less severe forms are characterised by defects in the meninges and vertebrae which overlie the posterior spinal cord.
Spina bifida can lead to paralysis beneath the affected region of the spinal cord. Sufferers may require crutches or wheelchairs to move about, and may also suffer from lack of bladder and bowel control.
Neural tube defects are among the most common and disabling birth defects, occurring in roughly 1 in every 500 live births.
Read more about this topic: Neurulation
Famous quotes containing the words tube and/or defects:
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—Germaine Greer (b. 1939)
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—Phyllis McGinley (1905–1978)