Large, round, epithelial-like cells

large, round, epithelial-like cells

• large, round, epithelial-like cells

• secrete nutrients and regulatory substances

• Important for successful placentation

Trophoblastic cells growing as columns into the decidua, forming anchoring villi

• Trophoblastic cells growing as columns into the decidua, forming anchoring villi

• Invading also the uterine arteries – eroding the media and forming the intima

• Important for maintaining perfusion of the placenta

• Inadequate formation: related to preeclampsia

• Ecxessive: invasive growth, e.g. choriocarcinoma

• 2d-3d week: The trilaminar germ disc formed

• 3d week: The heart develops, links up with the vascular system

• 4th week: Formation of the gut

• 6th week: Urogenital sinus formed

• 7th week: most organs have formed

6 weeks ~ 2 cm CR-length; nose, ears, fingers identifiable

• 6 weeks ~ 2 cm CR-length; nose, ears, fingers identifiable

• 10 weeks ~ 6 cm; external genitals formed but undifferentiated

• 14 weeks ~ 12 cm; external genitals can be differentiated, skin transparent red

• 18 weeks ~ 15 cm; fine hairs (lanugo) covers the body, skin opaque

• 22 weeks ~ 21 cm; eyebrows and fingernails present

• 26 weeks ~ 26 cm; eyes open, scalp hair growing