This week in anatomy and physiology we were talking about blood and the heart and circulation, and I had one of those mind blowing moments of amazement. I was especially struck when looking at the fetal circulatory system. I'd never really stopped to consider how it all works. Of course I knew that the baby receives oxygen from the mother through the umbilical cord and placenta, but I never thought about how fetal blood is actually circulated: how the lungs are non-functional until birth so blood is re-routed past them, and how the umbilical vessels and extra re-routing shunts are no longer needed after birth and are essentially "obliterated" (as my lab manual states) and remain only as fibrous ligaments. It's so crazy to think that this is the system that is going on while the fetus is developing and growing in utero, but then as soon as it's born, all of a sudden, the baby starts breathing, and using it's lungs, and circulating it's blood differently. How amazing! It's all so perfectly designed and functional. Pregnancy, and birth in general, gets me every time. It's so normal and natural, yet it's also unexpected. Who would have thought?! How amazing is it that we, as women, can grow another human, another life, inside of our own bodies? And then when development is complete, and all is ready, that other life is born. It's a little crazy, if you stop to think of it.