MODEL RELEASED. Human placenta for stem cell harvesting. National blood service nurse holding a dish containing a donated human placenta from which the umbilical cord stem cells will be harvested. The stem cells, which are able to develop into any type of blood cell, can be used to treat a number of diseases, including cancers, genetic diseases and blood disorders. The placenta lines the uterus (womb) during pregnancy, providing the foetus with oxygen and nutrients and removing waste products. The umbilical cord, which attaches the placenta to the foetus is attached to the forceps. Blood stem cells will be harvested from the placenta and umbilical cord and cryogenically stored (frozen).