Neuroembryology Flashcards
What does the notochord help develop?
The spinal cord and spinal nerves via signaling molecules
Turns the caudal/inferior neuroectoderm physically into these structures
What does the prechordal mesoderm help produce?
Brain and cranial nerve development via signal molecules
The rostral/superior neruoectoderm turns physically into the Brain and cranial nerves
What is the process of neural induction/Neurulation mainly give rise to?
Differentiates the ectoderm into the neuroectoderm (neural plate)
- neuroectoderm eventually turns into Brain/spinal cord
Also gives rise to neural tube and neural crest cells
What does surface ectoderm (ectoderm that does differentiate into neuroectoderm) give rise to ultimately?
The skin
What are the signaling molecules secreted ventrally in the neural tube?
SHH
RA
Noggin
Chordin
are all secreted from the ventral floor plate
What are the signaling molecules secreted dorsally in the neural tube?
TDF-B
BMPs
Dorsalin
RA
Noggin
all are secreted from the dorsal roof plate
What are the signaling molecules secreted lateral to the neural tube ?
BMPs
these are secreted form the somites
Dysraphisms
Various neural tube defects (NTDs)
- usually in formation and fusion of the neural tube
Usually occur at or near anterior/posterior neuropores
Highly linked to low maternal folate/B9 levels in conception and early pregnancy
Most heavily associated defects include cranium or spinal bifida
Different types of cranial bifida
Meningocele
- contents include just CSF and meninges
Meningoencephalocele
- contents include CSF, brain tissue and meninges
Meningohydroencephalocele
- contents include CSF, Brian tissue, ventricles and meninges
- most severe
Different types of spina bifida
Spina bifida occulta
- unfixed neural arch that does NOT produce a cyst
- asymptomatic except sometimes tuffs of dark hair form in the area
Spina bifida cystic w/ meningocele
- cyst forms and includes meningitis and CSF only
Spina bifida cystic w/ meningomyelocele
- cyst forms and includes meningitis, CSF, Brain matter and spinal cord tissues
Myeloschisis
Posterior neurochord does not close
Leaves open spinal cord exposed.
Not compatable with life
Meroencephaly
Anterior neurochord does not close
Causes exposed Brain
Does not affect and bones
What do the neural crest cells give rise to?
All glial cells of the PNS
Most of the PNS nerves and ganglia
Where are the primary sensory neurons for CN 1 and 2 located?
CN1 = olfactory epithelium fund in the nasal cavity
CN2 = retina of the eye
both do NOT originate from neural crest cells
What do sensory ganglia of the true cranial nerves originate from?
Either cranial neural crest cells of neurogenic placodes (thickened surface ectoderm)