INSIDE THE WOMB
Take a look inside the mammalian womb and discover how unborn cubs, kittens and calves grow
WORDS SCOTT DUTFIELD
Within the animal kingdom, there are three types of mammals: placentals, marsupials and monotremes. Placentals, like humans, carry a foetus within their uterus, also known as the womb. Once a fertilised egg attaches to the lining of the uterus, it develops over several weeks into an early embryo. Along with the development of an embryo, a new temporary organ called the placenta grows.
During development, the embryo produces root-like structures called villi, which anchor it in the womb. These villi grow, eventually connecting to the blood vessels of the mother, and the placenta starts to grow. The purpose of the placenta is to deliver nutrients and oxygen to the foetus. The connection between the foetus and the placenta is called the umbilical cord, which leaves a belly button after birth.