structures in implantation

1. Cleavage of Zygote• Begins about 30 hrs after
fertilization
• Zygote divides first into 2
then 4 then 8 & 16 cells

2. TROPHOBLAST
• It is the outer layer of cells of blastocyst.
• It develops into two membranes:
chorion,
amnion.

3. The chorion
• It grows finger like
projections called
chorionic villi
• Increases surface area
for absorption of
nutrients
• Secretes HCG which
prevents degeneration
of corpus luteum
• Villi forms part of
placenta

4. The amnion
• Forms a sac around
fetus
• Encloses amniotic fluid
• Shock absorber
• Protect fetus from
damage
• Keeps skin moist
• Provides room for
movement
• Act as heat buffer