Definitions

A flat, disc shaped structure that grows to around a 20cm in diameter and 2.5cm thick by term (37+ weeks). On the maternal side, it is made up of about 20 lobe like structures, called cotyledons, and on the foetal side, it is shiny as it is covered by the amnion (definition link). On the foetal side you can see both the umbilical cord (definition link) that protrudes from the centre, and the branches of the umbilical vein and arteries that spread from the base of the cord across its surface. It provides a medium for oxygen, nutrients, and waste products to be passed between maternal and foetal blood.