Cytotrophoblasts (Placenta Builder Cells)

The baby's builder cells

At the very start, a baby is a tiny ball of cells. The cells on the outside of that ball become trophoblasts. They will build the placenta.

Cytotrophoblasts are one kind. They are neat, separate cells, each with its own nucleus, sitting in a layer like tiles.

Building the placenta

• They split again and again to make more cells.
• Some of them join together to make the big outer layer of the placenta, called the syncytiotrophoblast.
• Some grow into the wall of the womb and widen the mother's blood vessels, so more blood reaches the placenta.

The placenta passes food and oxygen to the growing baby.

Cytotrophoblast quiz