EDELMANN / SCIENCE PHOTO LIBRARY. EDELMANN / SCIENCE PHOTO LIBRARY.
The human embryo after 6-7 weeks, showing the developing leg & foot: to the left is the body cavity containing the primitive heart (which has been formed & undergone partition since the 3rd week), lungs, liver (enlarged & producing red blood cells until the bone marrow takes over the function), & the gut with its associated glands (thyroid, pancreas, thymus & parathyroid). In the background is the umbilical cord, which connects the embryo with the placenta, an organ embedded into the wall of the uterus which serves as an interface between the embryo's & mother's circulation, exchanging nourishment & waste products.
Model release not required. Property release not required.