neuro chap Neurodevelopment

The development of the CNS is

multistep process and complicated. Problems during the development cause many issues of the developing infant and child.

Gastrulation a critical process takes place when

week 3 of human development.

an embryo transforms from a one-dimensional layer of epithelial cells, a blastula, and reorganizes into a multilayered and multidimensional structure called what

gastrula

the CNS arises from

the outer most layer of three layers of the gastrula, ectoderm

Spina bifida occulta

mildest form results in a small separation or gap in one or more of the bones (vertebrae) of the spine.

spinal nerves usually aren't involved. most children with this form of spina bifida have no signs or symptoms and experience no neurological problems.

Meningocele

rare form. meninges push out through the opening in the vertebrae.

Because the spinal cord develops normally, these membranes can be removed by surgery with little or no damage to nerve pathways

Myelomeningocele.

is the most severe. spinal canal remains open along several vertebrae in the lower or middle back. both the membranes and the spinal cord protrude at birth, forming a sac on the baby's back.

In some cases, skin covers the sac. Usually, however, tissues and nerves are exposed, making the baby prone to life-threatening infections.

What kind of impairment does myelomeningocele have

Neurological impairment — often including loss of movement (paralysis) — is common. So are bowel and bladder problems, seizures and other medical complications.

Second Critical Time Period occurs when

third trimester to 2 years of age. axonal growth and formation of synaptic connections between axons

When do the long axons form

Second Critical Time Period

What occurs during the second critical time period

make up the association axons, commissure axons, and projection axons. These axons make up the white matter of the CNS.

The last neurons to form are

the short axon neurons (the interneurons).

What occurs in final development

The brain will continue to grow, but not with more neuron growth, but with myelination of axons and proliferation of glial cells. If any part of this carefully orchestrated developmental sequence is disrupted devastating neurological consequences will occur.

What are The Three Germ Layers of the Gastrula

Ectoderm, Mesoderm, Endoderm