Vatican City is home to some of the most famous art in the world. St. Peter's Basilica, whose successive architects include Bramante, Michelangelo, Giacomo della Porta, Maderno and Bernini, is a renowned work of Renaissance architecture.
This is when the baby's brain, spinal cord, heart and other organs begin to form. The embryo is now made of three layers. The top layer â the ectoderm â will give rise to your baby's outermost layer of skin, central and peripheral nervous systems, eyes, inner ears, and many connective tissues. Your baby's heart and a primitive circulatory system will form in the middle layer of cells â the mesoderm.
Blastocyst: hollow ball of cells after five days. Trophoblast: forms early embryo, fetal membranes and placenta after five to seven days. Embryo: the developing human from fertilisation to the eighth week of pregnancy. Fetus: the developing human from nine weeks of pregnancy to birth at around 40 weeks. Neonate: newborn baby from birth to 28 days old.