Flashcards in 1.2 Development of the CNS Deck (22):
Why is the NS the most susceptible to insult during pre-natal development?
Because it takes a long time to develop
What process produces the notochord?
What is the role of the notochord?
What is the depressed mid-region of the neural plate called?
The neural groove
What produces the neural tube?
Neural folds gradually approach each other in the midline and fuse
What is the notochord?
Solid rod of cells running in the midline with an important signalling role
What does the notochord direct?
The conversion of overlying ectoderm to neurectoderm
By which day is the neural tube completely closed?
How long does neurulation take?
What are the two openings at the cranial and caudal end of the neural tube called?
Anterior and posterior neuropore
What do neural tube defects result from?
Failure of the neural tube to close
Can occur caudally or cranially
what does a cranial neural tube defect result in?
What does a caudal neural tube defect result in?
Where does spina bifida occur?
Can occur anywhere along the length
Most common in lumbosacral region
Is spina bifida associated with cognitive delay? Why?
It doesn't affect the brain
What nearly always occurs due to spina bifida?
What is anencephaly? Why does it occur?
Absence of cranial structures, including the brain
Due to failure of NT closure cranially
What is rachischisis?
Failure of neural fold elevation
Most severe neural tube defect
The neural tube fails to form and instead there is splayed nervous tissue across the surface of the foetal back
How can neural tube defects be diagnosed?
Raised maternal serum a-fetoprotein
How can neural tube defects be prevented?
Preconceptually (3months) and during the first trimester
Why does the cauda equina form?
After the 3rd month, the vertebral column grows faster than the spinal cord
Spinal roots must elongate because they still exit at their intervertebral foramen