In week 5, the baby's heart is taking shape. Two tubes in the embryo join together, creating a tubular structure that starts pulsing with the first beats. This tube will later develop into all the parts of the growing heart.
It’s during this stage that the embryo also starts to organize into three layers:
- the ectoderm,
- the mesoderm,
- and the endoderm – which will later form all of the organs and tissues
This is brain development, heart development, lungs, and gut - respectively.