Development of the CNS Flashcards
When does the CNS begin to develop?
beginning of the 3rd-week
What are Neural Crest Cells?
During the elevation of the neural plate, a group of cells in the ectoderm appears along each of the neural folds.
Closure of the Neuropores,
Cranial - 25th day
Caudal - 28th day
What are Neural tube defects?
These occur due to abnormal closure of the neural folds.
Neural tube defects can be prevented by…
giving Folic acid, at least 1 month before conception and throughout pregnancy.
Examples of Neural Tube Defects
Spina bifida
Anencephaly
Diagnosis of Spina Bifida
prenatally by determination of alpha-fetoprotein levels in maternal serum and amniotic fluid
3 types of Spina Bifida.
Spina bifida occulta, Meningocele, Myelomeningocele
What is Spina bifida occulta
Defect in the vertebral arches that are covered by skin.
Doesn’t involve underlying tissue.
Occurs commonly in the sacral region.
What is Meningocele
fluid-filled meninges protrude in the sac
Meningomyelocele
Neural tissue is also included in the sac.
What is Hydrocephaly?
part of the cerebellum herniates through the foramen magnum, which obstructs the flow of the CSF
What are Primary vesicles?
Three dilatations form at the cephalic end of the neural tube
What is Anencephaly?
Failure of closure of the cephalic part of the neural tube.
Therefore, the vault of the skull doesn’t form, leaving the malformed brain exposed.
Later this tissue degenerates.
List the primary vesicles.
Prosencephalon (Forebrain)
Mesencephalon (Midbrain)
Rhombencephalon (Hindbrain)
