Neurulation And Neural Crest (EMB) Flashcards
What releases SHH
Notochord
What is the neural plate
Forms neural tube and neural canal with help of neural crest plate
What does SHH do
Induces formation of neural plate
Neural ectoderm gives rise to what
CNS, brain, spinal chord
What does surface ectoderm give rise to
Skin/dermis
Neural crest cells came from what and not what
Come from neural plate, but do not form neural tube
What is caudal and Rostroal neuropore
Opening for neural tube at back and head - needs to completely close
What is primary neurulation
Process of closing and fusing ectoderm around neural tube
What is secondary neurulation
Fusing of caudal eminence with caudal neropore
Where are neural crests found
In cranial and trunk region
What do neural crest cells give rise to
Sensory neurons, cranial nerves 5,7,10, schwan cells, Pia matter, arachnoid matter, mylanocytes, chromaffin cells of suprarenal medulla, dermis of face and ventral neck, parts of large arteries, enamel and dentin in the teeth
Hirschsprung’s disease
Neural crest cells do not give rise to GI, and thus infant can not defecate
Albinisim can come from what defect in embryo
Neural crest cells
All spina bifida defects occur why
Because of caudal neural chord failure to close at the appropriate time, usually benign
What is meningocele and why does it form
Failure of caudal neural tube to close
The dura mater on the vertebra forming a cyst
No formation of neural arches or vertebra arches
Spinal chord is still within the vertebral foramen
What is meningomyelocele and why does it form
A cyst on the vertebra with the protrusion of neural tube
The spinal chord is outside of the vertebral foramen, but within the cyst
Patient do have deficits
Failure of caudal neural tube to close
What is myelocele and why does it form
Spinal cord physically outside the body
Patients do have motor and sensory deficits
Failure of caudal neural tube to close
What protein will be high with open neural tube defects (meningocele, meningomyelocele, myelocele)
Alpha-fetal protein
Problems with cranial neural tube defects result from what (ancephaly, encephalocele)
Failure of rostral neural tube to close
What is ancephaly
Not compatible with life, missing neocortex
What is encephalocele
cysts with or without brain tissue
That doe the meninges devolp from
Meninx primitiva, mesoderm in origin
Menix primitiva develops into what two cell groups
Pachymenix and leptomeninges
What is the meninx primitiva derived from
Cells of the sclerotome
Pachymenix gives rives to what
Dura mater
What does leptomeninges give rise to
Arachnoid and pia mater
