Card Set Information
Dizygotic twins define
fertilization of ova by 2 sperm
same or different sex
Dizygotic twins amnions and chorions
2 amnions, 2 chorions
mono zygotic twins define
singl sperm and ova
Identical twins who share a common monochorionic placenta
the shared placenta contains abnormal blood vessels
leading to unequal nutritional or oxygen needs
when is twinning not possible?
After second week
3rd week primitive streak migrates from caudal to cranial end.
creates notochord from primitive node between ecto/ endodermal layers
Teratomas are a result of
failure of the remnant primitive streak to regress.
Mermaid, caused by abnormal migration of mesoderm
vertebral defects, anal atresia, TE fistula, Renal defects
VATER + Cardiovascular defects and upper limb defects
Cranial part of Neural tube-Brain
neuropores fail to close