if the embryoblast or germ disc does not separate completely, what condition develops?
conjoined twins
how does situs inversus happen?
defective morphogen genes from hensen's node
what is an extreme example of caudal dysgenesis?
sirenomelia
disorders present at birth, produced by environmental and/or genetic causes. These can be morphological, behavioral and metabolic:
Birth Defects, Congenital Anomalies
if the neural tube fails to close in brain vesicles, what happens?
ancephaly
what is most common scenario for monozygotic twins, that is, when do they split?
embryoblast of the blastocyst splits in two
malformations produced over a prolonged period of time due to persistent molding forces, e.g. cranial shape change due to decreased amniotic fluid (oligohydramnios):
deformation
dizygotic twins are what? monozygotic?
fraternal, identical
morphological anomalies are called what?
congenital malformations
malformations produced after the initial formation of a normal structure, due to abruptly occurring destructive forces, e.g. amniotic band disruption complexes causing in utero amputation:
