Congenital Diseases Associated With The Central Nervous System Flashcards
What does the neural tube give rise to?
Brain Spinal cord Cranial and spinal nerves Eyes and other sensory organs Neural crest
When is the neural tube formed?
In gastrulation at week 3/4
What happens as the neural tube closes?
Becomes patterned along the dorso-ventral and rostro-caudal axis
What are defects classified according to?
Stage thought to be affected
What are the classifications of neural tube defects?
Early CNS patterning
Neural tube closure
Regional brain defects
What is an example of an early CNS patterning defect?
Holoprosencephaly
What are some examples of neural tube closure defects?
Chraniorachischsis
Exencephaly
Spina bifida
How many neural tube closure points are there?
Three main and two others
Where is the first closure of the neural tube?
Between hindbrain and spinal cord
Where is the second closure of the neural tube?
Between forebrain and midbrain
Where is the third closure of the neural tube?
Most rostral portion of forebrain and only progresses posteriorly
Where is the fourth closure of the neural tube?
More rostral and within the hindbrain than closure 1
Where is the fifth closure of the neural tube?
Most posterior point so only progresses anteriorly
What are the two modes of neural tube closure?
Primary or secondary neurulation
What happens in primary neurulation?
Rolling up of tube
Closure is by fold apposition then ‘zipping up’