Development of NS Flashcards
What induces the ectoderm to differentiate into the neural plate?
notocord and paraxial mesoderm
what protein is inducing the ectoderm developing into skin?
BMP4
what protein does the notocord secrete to develop into nervous tissue?
BMP4 antagonists - noggin, chordin, follastin
when does the NS first appear?
3rd week
what forms the neural plate?
the neural groove deepening
what neuroectodermal cells form from the neural groove?
neural crest cells
what does the neural tube differentiate into?
cns
what do the neural crest cells give rise to?
pns and autonomics ns
what does the neural canal communicate with?
amniotic cavity
closure of neural tube occurs first in
cervical region
neural tube openings are:
neuropores (rostral and caudal)
around what day do that neuropores close?
rostral - day 24
caudal - day 28
the walls of the neural tube thickens to form
brain, brainstem and spinal cord
somites give rise to
vertebrae and ribs
dermis on dorsal skin
skeletal muscles
what zone gives rise to all neurons and macroglia?
ventricular zone
what zone forms the precursors of white matter regions of the spinal cord?
marginal zone
primordial neurons are called:
neuroblasts
neuroblasts form the ____ zone between ventricular and marginal
intermediate zone
which plate is a signaling center for BMPs and Wnts
roof plate (dorsal)
which plate is a signaling center for Shh
floor plate (ventral)
which plate is a precursor of sensory gray matter?
alar plate (dorsal)
which plate is a precursor of motor gray matter?
basal plate (ventral)
helps pattern the organization of the basal plate
Shh
helps pattern the organization of the alar plate
BMPs
all sensory cells from the pns are derived from:
neural crest cells
when does myelination begin?
late fetal period and continues during 1st postnatal yr
differences in the thickening of the lateral walls produces a shallow longitudinal groove on each side of the neural (central) canal
sulcus limitans
where does the newborn spinal cord end at?
L3 - infants
L1 - adults
during what week do the brain flexures appear?
week 4
midbrain and cervical
three primary vesicles:
prosencephalon
mesencephalon
rhombencephalon
five secondary vesicles: 5th week
telencephalon
diencephalon
mesencephalon
metencephalon
myelencephalon
thalamus cavity:
third ventricle
midbrain cavity:
aqueduct
medulla cavity:
fourth ventircle lower part
pons cavity:
upper part of fourth ventircle
cerebral hemisphere cavities:
lateral ventricles
a ventral marker, is induced by Shh in the floor plate and repressed by BMPs in the roof plate
Pax6
a dorsal marker, is repressed by Shh and induced by BMPs
Pax7
Anomalies involving the vertebral arches
spina bifida
Type of upper NTD that occurs when the anterior part of the neural tube (anterior neuropore) fails to close at week 4 of development
Anencephaly
The brain fails to grow sufficiently, resulting in a smaller than normal brain
Microphaly
The forebrain fails to develop into two hemispheres, with a resulting loss of midline structures that lead to malformations of the brain and face.
Holoprosencephaly
Defects related to an accumulation of cerebrospinal fluid (CSF)
Hydrocephalus
Caudal displacement and herniation of cerebellar structures through the foramen magnum
arnold-chiari malformation
a congenital brain malformation involving the cerebellum and the fluid filled spaces around it
enlarged 4th ventricle and cyst
Dandy-walker syndrome
Microglial cells arise from_____ after the production of neuroblasts has ceased.
mesenchyme
myelomeningocele is related to what condition?
arnold-chiari
