Morphogenesis Flashcards
Name 6 steps of neurolation
- Neuroplateo develops in mesoderm (18 days)
- Neural groove forms (20 days)
- Central canal forms (22 days)
- Sensory ganglia form (24 days)
- Closure of anterior & posterior neuropores
The central canal forms
Ventricular system
Sensory ganglia are derived from
Neural crest cells
Which molecule is important for the initiation of neurolation?
BMP
What inhibits BMP
Niggin, chordin & folistati
Sensory ganglia are derived from
Neural crest cells
Which molecule is important for the initiation of neurolation?
BMP
Which molecule is important for ventralization?
What produces the molecule?
Sonic Hedgehog
Notocord & floor plate
Which molecule is important for dorsalization?
What produces the molecule?
TGF-beta
BMP
Dorsain
Vitamin A
What induces floor plate formation?
Notocord
Alar plate
(motor or sensory)?
Sensory
Basal plate
(motor or sensory)?
Motor
Which molecule is responsible for setting rostral-caudal direction?
Retenoic Acid detemines caudal direction
Excess external retencacid is
fatal
Retinoic acid determines the expression of
HOX genes
Derivatives of neural tube (2)
- All CNS cells
2. Macroglia
Horizontal cleavage on precursor neural cells results in 2 cells each containing 1 of 2 molecules, name them
- Notch
2. Numb
Fate of the cell that contains NUMB
Synthesizes NUMB so that it can undergo cleavage again
Fate of the cell that contains NOTCH
undergo differentiation
More DELTA: neuroblasts
More NOTCH: glioblasts
Describe lateral inhibition as it relates to dividing precursor cells that end up with mor NOTCH
Alternate between neuroblasts and glioblasts
Post-mitotic cells migrate from _____ to the ____ and extend axons into ________.
Ventricular zone
Mantle zone
Marginal zone
Where are cell bodies during the S phase?
pial surface
Where are cell bodies during M phase?
Lumen side/ Neural Tube side
Name 3 primary brain vesicles
Prosencephalon
Mesencephalon
Rhombencephalon
Name 2 divisions of prosencephalon
Diencephalon & Telencephalon
What does the mesencephalon form
Midbrain (still called mesencephalon)
Name 3 division of rhombencephalon
Spinal cord
myelencephalon
metencephalon
Pontine flexure seperates
myelencephalon
metencephalon
Name embryonic origin
Lateral vesicles
Telencephalon
Name embryonic origin
Optic vesicles
Diencephalon
Name embryonic origin
Cerebellar aquaduct
Mesencephalon
Name embryonic origin
4th ventricles
Myelencephalon & metencephalon
Cephalic flexure separates
Prosencephalon & mesencephalon
Failure of the anterior neuropore to close
Anencephaly
Failure of the posterior neuropore to close
Spina bifida
Abnormal development of midline structures (single brain ventricle, single eye)
Holoprosencephaly
Neural Tube completely closed but not encased in mesoderm
spina bifida occulta
Meninges and sometimes the spinal cord bulge from the opening where the posterior neuropore should have closed?
Meningocele
