As the body’s only disposable organ, the placenta is a materno-fetal organ and a crucial blood connection between the mother and developing foetus. It develops upon implantation of the blastocyst – the very early stage embryo – in the uterine wall and provides nutrition, gas exchange, waste removal and hematopoietic stem cells, along with endocrine and immune support for the foetus as it grows.
This placenta is from a pregnancy of twins and has been preserved in a formaldehyde solution. For a majority of monozygotic (identical) twins, a single placenta is shared throughout development. By contrast, fraternal (non-identical) twins always have separate placentas.
Human tissue, Wentworth solution, perspex, c1950
Image: Gavan Mitchell