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.
In humans, the embryo refers to the growing organism after being a zygote and before being a fetus. The zygote becomes an embryo immediately after series of cell division. After the continuous cell division and differentiation in eight weeks, the embryo becomes a fetus in which the organism undergoes extensive organogenesis. Word origin: Ancient Greek embruon (fetus), from en-, in- + bruÅ (grow, swell) Related term(s): embryonic; embryology; embryogenesis; presomite embryo; homogametic embryo; Embryo - Animals; Embryo - Plants