Thursday, April 9, 2009
Anatomy and Physiology Week 12
This week one of the things we talked about was Fetus Circulation. There is one umbilical vein and two umbilical arteries to the fetus. The umbilical vein carries oxygenated blood and the right and left umbilical arteries carries partially oxygenated blood. In the fetus the oxygen rich blood mixes with the oxygen poor blood through the liver to make partially oxygenated blood. The liver filters the blood coming from the mother before it circulates through the fetus' body(what a great idea). The ductus venosus dumps partially oxygenated blood from the liver into the inferior vena cava to the heart. At the right atrium a small amount of blood goes to the lungs, the other portions go through 2 other pathways. One is from the right atrium to the left atrium through the interatrial septum(through the foramen ovale of the heart). The other is from the right atrium to the right ventricle to the pulmonary semilunar valve to the pulmonary trunk through the ductus arterious to the aortic arch. 6-8 weeks after birth the ductus venosus and ductus arteriosus fills with collagen and closes. The ductus venosus then becomes the ligamentum venosum and the ductus arteriosus becomes the ligamentum arteriosum. At birth when the infants bottom is spanked to catch its first breath there are pressure changes in the thoracic cavity from the diaphram which causes the foramen ovale to close becoming the fossa ovalis. This is all very amazing to me. It is crazy to think about all the things that have to come together at the right times for us to be alive.
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Hey, so we talked a little about the whole C-section and child birth in lab class today. You seemed content on not having children. Why is that? Does the whole being pregnant disturb ya or is it the whole birthing process? They make drugs for it now....they work pretty good from what I hear.
ReplyDeleteHaving just had a baby, I never really thought about how she was able to get blood coursing through her. It is a pretty intricate process, and I wish I had learned about it more while I was pregnant! I am glad I was careful with what I ate as well as being careful in not being around things that could potentially harm the baby. I am glad that things get processed through the mother's liver before it is passed along to the fetus too. It is a good line of defense for the baby! I even made sure that I wasn't around things like paint fumes and cigarette smoke. The human body just does amazing things, and when it comes to reproducing there are so many complicated things that go it is kind of mind boggling to fathom. All I know is that if all goes well, a baby is a beautiful thing and a life changing moment:)
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