Developmental Disorders of CNS Flashcards
Nervous system develop from ____ germ layer.
ectoderm
Regionally thickened ectodermal germ layer =
neural plate
Gives rise to most of the PNS
Neural crest
Anencephaly =
Failure of closure of rostral part of neural tube
Absent cranial vault, forebrain –> incompatible w/ long-term postnatal life
Protrusion of brain and meninges through defect in skull.
Encephalocele
Herniation of spinal cord and meninges through defect in vertebral column.
Myelomeningocele
T/F: Myelomeningocele is incompatible w/ long-term postnatal life.
False.
Early surgical repair improves change of survival.
Which of the following is NOT one of the 3 vesicles that form from the neural tube? A. Mesencephalon B. Myelencephalon C. Prosecephalon D. Rhombencephalon
B. Myelencephalon and metencephalon is a subdivision of rhombencephalon.
Prosecephalon = forebrain Mesencephalon = midbrain Rhombencephalon = hindbrain
T/F: Mesencephalon divides into diencephalon and telecephalon.
False. These are subdivisions of prosecephalon (forebrain).
Mesencephalon does not subdivide.
Telecephalon becomes ____
cerebral hemisphere
Diencephalon becomes ____
thalamic structures
Mesencephalon becomes ____
midbrain
Metencephalon becomes ____
pons and cerebellum
Myelencephalon becomes ____
medulla oblongata
Complete failure of primitive forebrain to diverticulate into two telencephalic vesicles.
Holoprosencephaly