Now about three quarters of an inch (17-22 mm) long, about the size of a grape, your embryo is starting to look distinctly human. Fingers and toes, although webbed, are defined. Knees have formed in the legs and the arms bend at the elbow. The tail recedes as the legs grow in size. The embryo now moves its body and limbs, although it's too small for you to feel those movements just yet.

Inside, too, there's a lot going on. Amazingly, fully 99% of all the muscles can be identified, and every internal organ is present (though not fully developed). Threadlike nerves are feathering themselves throughout the body. Sex organs are developing. Blood circulates in vessels throughout the tiny body, distributing oxygen and food and carrying away waste. The baby's lungs won't function until birth, however: embryo and fetus are completely dependent on the mother to provide oxygen and nutrition via the umbilical cord.