Systems development I: Spina Bifida

Question 1

What is spina bifida?

Answer 1

(Literally, split spine) Developmental congenital disorder caused by the incomplete closing of the embryonic neural tube

Question 2

What are the three different types of spina bifida?

Answer 2

Spina bifida occulta
Meningocele
Myelomeningocele

Question 3

What is spina bifida occulta?

Answer 3

(Least severe) the actual defect isn’t clear except for a patch of hair. This is a marker that the spine hasn’t correctly formed in that area. However, it’s sufficiently normal for there not to be a bulge of tissue

Question 4

What is the main component of meningocele?

Answer 4

CSF

Question 5

Why is myelomeningocele the most severe?

Answer 5

Neural tissue is bulging out in the gap of the spine

Question 6

Where is the functional effect of spina bifida?

Answer 6

Below the level of the anatomical defect

Question 7

When does formation of the nervous system start?

Answer 7

3 weeks PF

Question 8

What does the nervous system start off as?

Answer 8

Neural plate- flat plate of neural tissue

Question 9

Describe the development of the central nervous system simply

Answer 9

The neural plate folds and these folds increase in size over 3-4 days. As the folds rise up, they will eventually meet in the middle forming a tube- the CNS (this is all directed by the notochord)

Question 10

What happens after formation of the neural tube?

Answer 10

The fusion event starts at the middle of - then there’s zipping up towards the head and tail of the embryo. Under normal circumstances, the zipping up takes place over a few days. At the end of this process, there’s a gap at the tail and head of the embryo

Question 11

Which process is there a lack of in spina bifida?

Answer 11

The zipping up and fusion process which forms a gap

Question 12

What does the neural tissue direct formation of and why?

Answer 12

Formation of spinal bones- if they formed independently, then the bones would cut off the bulges of neural tissue from the spinal cord. The defect in the sealing up of the spinal cord leads to a defect in the formation of bones at exactly the same point

Question 13

What is the incidence of spina bifida like?

Answer 13

1-2 in 1000 pregnancies

Question 14

How effective is surgery at treating spina bifida?

Answer 14

It can help with the anatomical defects but not necessarily the functional problems

Question 15

What have studies shown a link between a lack of in the mothers diet and spina bifida?

Answer 15

Folic acid- Folic acid should be added to the diet significantly before the development of the defect