Fetal Circulation (Nursing School)
Fetal Circulation can be one of those tricky concepts to read about and fully visualize and understand.
Today we will take a little adventure through the fetal circulatory system to make sure you understand how fetal circulation inside a momma is different from the fetal circulation once the baby is born and from adult circulation.
Here’s a quick breakdown (with time-stamps):
– The 3 key differences between adult and fetal circulation (1:28)
– Your easy fetal circulation breakdown, step-by-step (3:17)
– An easy memory trick to help you remember the umbilical arteries vs. vein (5:57)
– What happens after the baby is born (the holes MUST close!) (6:16)
VIDEO TRANSCRIPT:
What’s up my friend?! What’s going on? I hope you’re have a beautiful day! I could not be having a better day, despite the fact that we found not 1, but 2 CATERPILLARS in our salad the other day, and now I’m scared to eat salad ever again. The best part is though, that my husband got BOTH of them! But now that I think about it, the chances of there being more than 2 in there are pretty high, so I wonder if I actually ate one without realizing it. Gross.
Have you ever found a bug in your salad before? Please tell me yes, so I feel less alone. But actually, a part of me wants to think it rarely ever happens, and that this was just once in a blue moon, so I’m not worried about it happening ever again.
ANYWAY…you’re probably wondering why we’re sitting here in my office at home… well I have a super fun video planned for you today. We are going to walk through fetal circulation. But I’m actually going to draw it out for you here on my computer, so this is going to be new and exciting. So if you are taking OB or maternity in nursing school right now, or if you’re headed that direction, listen up. Because you will absolutely be tested on this at some point and I want you to do amazing on your exam.
There are some really key differences between the blood circulation of an adult, vs the blood circulation of a baby inside it’s momma. If you haven’t watched the previous video I did on the pathway of blood flow through the heart, make sure to check that one out first and then come back to this video. Because you really need to know what an adult heart looks like before you can learn the differences between that and a baby’s heart when it’s inside the momma.
So, I’m going to trace it out for you so you can follow along and so you’ll finally understand it after this. So let’s do it.
The first thing you need to know is that there are 3 key differences in fetal circulation: the ductus arteriosus, the foramen ovale, and the ductus venosus.
The ductus arteriosus is a little hole that connects the pulmonary artery and the aorta to divert blood away from the lungs. When the baby is inside it’s momma, it’s not using it’s lungs the breathe, so this ductus arteriosus will allow blood to bypass the lungs and give more blood to the rest of the body.
The foramen ovale is another little hole that connects the left and right atrium. Since the baby isn’t breathing itself, it doesn’t need to move blood into the pulmonary circulation to get oxygen, it already comes in oxygenated from the momma. So the foramen ovale is a little hole here that allows blood to pass from the right atrium into the left atrium, which helps to bypass the pulmonary circulation.
And finally, the ductus venosus is the last one you’ll need to know about, and this one is located between the umbilical vein and the liver. The baby isn’t using it’s liver either when it’s inside the momma, so the ductus venosus allows blood to pass from the umbilical vein into the inferior vena cava. Some blood does go to the liver, but this opening allows more blood to go to the rest of the baby’s body.
So those are the 3 key things you need to know. So let’s draw this pathway out.
The path of blood flow in a baby starts in the placenta, and oxygenated blood travels through the umbilical vein into the liver area through the DUCTUS VENOSUS which allows blood to bypass the liver and meet the inferior vena cava.
That blood then dumps blood into the right atrium, along with the superior vena cava.
From there, some of the blood goes into the right ventricle and into the pulmonary artery (to go to the lungs), but the majority of it moves to the left atrium through the FORAMEN OVALE.
The DUCTUS ARTERIOSIS is an opening in the pulmonary artery to the aorta to help shunt blood even more away from the lungs.
So some of the blood that ended up in the right ventricle, will flow out from the pulmonary circulation, and into the aorta and to the baby’s body.
This just helps to get as much blood to the baby’s body as possible, because the baby isn’t using their lungs yet and doesn’t need as much blood there right now.
From the left atrium, blood goes into the left ventricle, into the aorta, and is distributed through the baby’s body and back to the placenta through the umbilical artery.
So that is the pathway of fetal circulation! It’s super important to mention that when the baby is born, all of these holes should close, so the baby’s lungs and liver will get blood.
I hope this breakdown helped you understand fetal circulation more for nursing school.
And of course, if you need more help with OB, maternity, or newborn topics for nursing school, you’ll definitely want to check out the Maternal/Newborn course we have for you inside the NursingSOS Membership Community. I get a lot of requests from students asking for more in-depth help on nursing school topics, and this is the best way that I can help you. When you join, you’ll get access to all of our courses, covering topics like med-surg, fluids and electrolytes, how to study pharmacology, how to write care plans, critical care, and yes, maternity and newborn. You’re going to LOVE it!
Thanks for watching friend, now go become the nurse that God created only YOU to be. And I’ll catch you in the next video!
