L19- defects in development Flashcards
what % of newborns congenital defect
3-4%
when is embryo most susceptible to congenital defects and infectious agents
first 3-8 weeks (embryonic period)
what organs are most commonly affected congenitally during development
heart and circulatory system
what % of births have some type of defect
20%
of this, 25% major 25% minor
what structure gives rise to the CNS
neural tube
examples of endodermal defects
absent lung (lung aplasia) omphacoele (bowel in umbilical cord) oesophageal fistula (oesophagus connects to trachea)
derivatives of the neural crest
(PNS) sensory neurons autonomic neurons schwann cells smooth muscle
what germ layer gives rise to neural crest
ectoderm
what does epiblast give rise to
3 germ layers
what defect can drinking alcohol whilst pregnant lead to
fetal alcohol syndrome - small head
examples of mesodermal defects
skeletal defects
limb bone defects (Liebenberg syndrome)
polydactyly
what protein promotes formation of digits
sonic hedgehog (SHH)
examples of ectodermal defects
spina difida