Medical visualization taken from human scanned data showing the internal structures of an embryo at 10 weeks after fertilization. A lateral view (left) is shown, as well as a posterior and anterior view (middle and right). Week 10 is a significant week for the developing embryo, as the end of this week marks the beginning of the fetal period. At this point the body measures just over an inch (28-30 mm) long, is about the size of an almond in its shell, and weighs just 1/30 oz (.9 g). Internally, all of the body's myriad parts cells, tissues, organs, systems have been differentiated. The diaphragm has formed, the heart is now functionally complete, and major blood vessels assume their final plan. The lungs have divided into lobes and are laced with tubules, and the intestines begin to move from the umbilical cord into the body cavity. |