lecture 21 - nervous system development & disorders

Question 1

What are the basic steps in neural tube formation?

Answer 1

1. neural plate formation from the neural ectoderm
2. neural tube formation as borders of neural plate meet medially
3. neural tube closure then anterior and posterior neuropor closure

Question 2

What is the consequence of failure of the anterior neuropore to close?

Answer 2

foetus develops without a brain, usually fatal prenatally

Question 3

What is the consequence of failure of the posterior neuropore to close?

Answer 3

Spina bifida

Question 4

What are the 3 type of spina bifida?

Answer 4

Spina bifida occulta, meningocele, myelomeningocele

Question 5

What is a meningocele?

Answer 5

Failure of closure of the posterior neuropore. The dorsal epidermis and vertebral column remain open but the spinal cord and spinal nerves remain in place

Question 6

What is a myelomeningocele?

Answer 6

Failure of closure of the posteior neuropore. Spinal cord and spinal nerves are found externally in a pocked formed by the meninges

Question 7

What is the biggest protective factor in preventing neural tube defects?

Answer 7

Adequate folate inrake

Question 8

What is anencephaly?

Answer 8

An absence of the embryological development of the forebrain and surrounding skull, caused by failure of the anterior neural tube to close

Question 9

What is encephalocele?

Answer 9

A neural tube defect where the brain and surrounding membrane protrude through openings in the skull.