Changes

Cells of the neural plate proliferate, causing the neural plate to thicken. Cells then converge at the midline and become wedge shaped, which drives the neural plate to become long and narrow. Cells along the midline descend ventrally and contact the notochord, forming a "hinge". This forms a depression which is called the '''neural groove'''. Either side of the neural groove, ectoderm converges towards the midline. This causes elevations either side of the neural groove, called '''neural folds'''. Hinges form at the foot of each neural fold, allowing the folds to be brought together, forming a tube. The tube sinks, as non - neural ectoderm fuses above the neural tube, "zipping" the neural tube up. The non - neural ectoderm will form epidermis. Failure of the neural tube to close causes '''spina bifida''' (spinal cord protrusion) and '''exencephaly''' (brain located out of the skull).  

Cells of the neural plate proliferate, causing the neural plate to thicken. Cells then converge at the midline and become wedge shaped, which drives the neural plate to become long and narrow. Cells along the midline descend ventrally and contact the notochord, forming a "hinge". This forms a depression which is called the '''neural groove'''. Either side of the neural groove, ectoderm converges towards the midline. This causes elevations either side of the neural groove, called '''neural folds'''. Hinges form at the foot of each neural fold, allowing the folds to be brought together, forming a tube. The tube sinks, as non - neural ectoderm fuses above the neural tube, "zipping" the neural tube up. The non - neural ectoderm will form epidermis. Failure of the neural tube to close causes '''spina bifida''' (spinal cord protrusion) and '''exencephaly''' (brain located out of the skull).  

=== Secondary Neuralation ===

=== Secondary Neurulation ===

Secondary neuralation occurs posteriorly, from the lumbar level onwards. The neural plate descends ventrally and medially. Cells of the neural plate condense and form a solid rod called the '''medullary cord'''. It is then made hollow by cavitations which join up to make a lumen. Tubes formed by primary and secondary neuralation fuse together to make one continuous tube called the '''neural tube'''.  

Secondary neuralation occurs posteriorly, from the lumbar level onwards. The neural plate descends ventrally and medially. Cells of the neural plate condense and form a solid rod called the '''medullary cord'''. It is then made hollow by cavitations which join up to make a lumen. Tubes formed by primary and secondary neuralation fuse together to make one continuous tube called the '''neural tube'''.

== Neural Tube Development ==

== Neural Tube Development ==