Amniocentesis, is a diagnostic test in which the amniotic fluid is withdrawnusing a needle, and under ultrasound guidance, in order to obtain a sample offoetal exfoliated cells.

the brain called the ventricles,where cerebrospinal fluid is found.

The Anterior or cranial neuropore closes about day 24.The Posterior or caudal neuropore closes at about day 26.The anterior portion of the neural tube eventually forms the brain while theposterior portion of the neural tube forms the spinal cord.The cells of the neural crest will differentiate to form the components of theperipheral nervous system.The notochord degenerates and only persists as the Nucleus Pulposus of theintervertebral discs.Other mesoderm cells differentiate into the somites, the precursors of the axialskeleton and skeletal muscles.

So, how does this neural tube form?During the third gestational week, a crease or fold appears in the neural plate.The crease rapidly deepens and becomes known as the neural groove. Theentire embryo is lengthening as this happens. As the neural groove continuesto deepen, the lateral edges of the plate begin to rise like two ocean wavescoming together. These edges are called the neural folds, and the tips of theneural folds are called the neural crest cells. As the neural folds approacheach other and start fusing, these neural crest cells just separate from theneural folds and form their own layer. Now the neural folds fuse in the midlineto form a neural tube.

Methylenetetrahydrofolate reductase (MTHFR) gene mutations have beenlinked to an increased risk of neural tube defects in babies.

The frontal lobe is the largest of the four lobes and is involved with highercognitive functions, including problem-solving, decision-making, attention,intelligence, and voluntary behaviors