Fetal Circulation (Before and After Birth) Maternity Nursing Heart Shunts NCLEX

hey everyone it's sarah thread sterner sorry and calm and today we're going to talk about fetal circulation and as always whenever you get done watching this youtube video you can access the free quiz that will test you on this content so let's get started to help us understand fetal circulation we first have to go back and review the normal blood flow of the heart like we need to know how the blood actually flows through a heart that is outside of the uterus that's not depending on a placenta and we need to know where deoxygenated blood is versus oxygenated blood because the biggest difference between a person's heart whenever they're outside of utero compared to whenever they're inside of utero is that inside of utero they have these shots that are shunting hints pushing away or pulling away blood from the lungs because in utero the person the baby is not using their lungs they're full of fluid but whenever they're born they do use their lungs so those shunts aren't needed anymore because we actually need that blood to go through the lungs so first let's review the blood flow through the heart so everything starts on this right side and here in this illustration in the blue this is our right side and over here this is our left side so what's going on on the right side is that all this blood is draining back to your heart it is very low in oxygen because that oxygen has went and replenished your tissues and organs so they continue to work so now it goes on to the right side and it's whole goal is to get to the lungs because the lungs are going to replenish that deoxygenated blood with oxygen and then after it does that it's going to enter into the left side which is going to pump it up through your body and replenish your organs and tissues with oxygen and it's just constantly cycling like this so everything we have this inferior vena cava in the superior the vena cava and blood is draining back to those the blood is going to go down into the right atrium the and it's gonna flow down into the right ventricle the right ventricle is going to pump it up through the pulmonary artery right now it's still low in oxygen but once it leaves the pulmonary artery it's gonna hit the lungs where gas exchange is going to happen so the build-up of waste in your blood like carbon dioxide is going to cross over you're going to exhale that out and the oxygen that you've taken in is gonna cross over and go in the blood and replenish it so over here I have the deoxygenated represented in blue letting you know it's really low in oxygen so once I hit stop those lungs it's gonna flow back through into the pulmonary vein so now we're into the left side of the heart and it's red it's really high in oxygen so it's going to go into the left atrium down through the left ventricle which is really strong and it's going to pump that blood up through the aorta and it's going to shoot up through here go to your brain your upper extremities it's also going to flow down through here through the descending aorta and replenish your lower extremities so as you can see the right and left side they work beautifully together but they really have their own job the right side is going to take deoxygenated blood pump it to the loans the left side is going to take that oxygenated blood it just receive from the lungs and pump it throughout the body so the heart and the lungs they work beautifully together now as you can see in this heart there are no shunts or a little passageways that's allowing blood to flow in different directions which would help bypass the lungs because we're using the lungs so the lungs need this blood flow so gas exchange can't occur now that is what's different in this fetal heart circulation here our lungs are not working they're non-functional they're full of fluid but whenever that baby is born takes their first breath those loans those Abiola sacs they pop open baby starts breathing gas exchange starts to occur however before that even happens while they're still in utero the lungs aren't work so we need a little bit of blood flow to go to those lungs to maintain that lung tissue but we need majority of it to bypass the lungs so to do that in the fetal heart and in circulation we have three shunts all of those three shunts two shunts play a huge role with shunting blood away from the lungs so for exams you want to remember the names of these shunts where they're located and how blood flows through them so the shunt I want you to remember are the ductus venosus the foramen ovale and the ductus arteriosus the ductus venosus is located over here with the liver and we're going to go in depth with these here in a moment the foramen ovale is located between the right atrium and the left atrium and the ductus arteriosus helps connect the pulmonary artery to the aorta now you may be wondering okay we're bypassing the lungs so the lungs aren't providing oxygen to the blood but this baby that's growing in the uterus still needs oxygen in their blood so their brain can develop and their whole body and all those vital organs so how are they getting oxygen in their blood well they're getting it from the placenta now the placenta along with the umbilical cord which attaches to the baby is like the lifeline for that baby whilst developing in the uterus if you don't have a healthy placenta there's gonna be issues with the baby growing and developing properly along with major complications that can happen so the placenta what it does is it embeds itself in the uterus and when it does this it in a sense connects with moms circulation because this placenta what it's gonna do is it's going to give the baby oxygen and nutrients that it pulls from Mom's circulation Cinda through the umbilical cord go to baby and then baby's gonna use it up produce its own waste and it needs to get rid of it so the baby will send it back through the umbilical cord to the placenta which will go into moms circulation and mom will clear it so think of the placenta as like the temporary lungs for the baby until they're actually able to use their own set of lungs now for exams what you want to know is really about this umbilical cord specifically about the umbilical vein and the umbilical artery like how many there are of each and what type of blood they carry so with this umbilical cord there's usually in most babies there is only one umbilical vein and what this umbilical vein does is it carries oxygenated blood so it's gonna carry it away from the placenta it's illustrated here in this red and you can see the arrows and it's going to take it away from the placenta because it's rich in oxygen and nutrients and send it to the baby now there are two umbilical arteries and they carry deoxygenated blood so blood that's really low in oxygen so here it's represented in blue we have the arrows going back to the placenta so the baby has used up that nice nutrients and oxygenated blood that the mom sent it but now has waste in it and it needs to get reoxygenate 'add so it's going to leave via these two umbilical arteries and send it back to the placenta so now let me walk you through fetal circulation of a baby who is in utero and then follow that up with how that fetal circulation changes once they are born and they start breathing on their own so we're gonna start here about this placenta and specifically we're gonna start at the umbilical vein how many umbilical veins are there one and what kind of blood does it carry oxygenated so it has nutrients and oxygen in it so it has pulled from Mom's circulation that oxygen and nutrients and it's gonna flow down through this vessel and then it's going to hit the liver now the liver is not fully functional yet but it does have some blood flow so some of that blood is going to go through the paddock portal vein the majority of it is going to be shunted to the inferior vena cava so this is our first shot the ductus venosus so the ductus venosus is going to help shunt this rich oxygenated nutrient-rich blood and it wants to get it to the heart so it's going to enter in to the inferior vena cava now also and then fear your vena cava just like over here with a normal heart blood flow it's blood that's draining back from the baby that is low in oxygen that's a deoxygenated so this blood is going to flow up and it's going to enter into the right atrium just like how it did over here now there's some really cool things going on in this right atrium first of all most of this rich oxygenated blood is actually going to flow over here to this left side via a shunt which is our second shunt called the foramen ovale so the frame in ovalle is going to connect your right atrium to your left atrium because remember what did we say over here was the whole goal of this right side to get deoxygenated blood to the lungs but over here our lungs aren't working so we need to take this fresh blood with oxygen that we just received from mom and we need to get it to this left side because the left sides want to get it to the body we don't need it to go through this right side and hit the lungs so majority of this fresh rich rich oxygenated blood is going to go and flow over here into the left atrium it's going to go down into the left ventricle up through the aorta and replenish the body now another thing that is occurring in this right atrium is the flow of blood draining back to the body that is deoxygenated so you have the superior vena cava flowing in this deoxygenated blood a majority of this blood is actually going to go down into this right ventricle because the body needs to get this deoxygenated blood back to this placenta and how it's going to do this is it needs it to go here on this side so the blood is going to flow down here hit the right ventricle now also some of this rich oxygenated blood that came from this umbilical vein is also going to flow down in here as well so the blood is going to be mixed with oxygenated and deoxygenated blood and it's going to be pumped up through the pulmonary artery now normally this pulmonary artery was sent it to the lungs well it will sing a little bit to the lungs just to maintain the lung tissue but most of it is going to actually be shunted away and this is where our third son is this is the ductus arteriosus so it's going to be shunted from the pulmonary artery into the aorta so that's what our ductus arteriosus does it connects our pulmonary artery to our aorta now you may be wondering how is this able to happen how are these structures able to allow blood to be shunted here into cross from right atrium to left atrium well there's a pressure difference let me go over this with you real fast in these lungs that are non-functional the resistance is really high because there's fluid in there because it's really high it's making the pressure in this right side a lot higher than the left side so because we have that pressure difference this allows oxygenated blood to easily flow through this frame and ovalle and hit this left side also it allows the blood to just flow up through this ductus arteriosus into the aorta because it's easier for blood to flow from a higher resistance to a lower resistance now keep that in mind because after birth those pressures are going to change and that is what really affects our shunts and helps them still close off so just keep that in mind so majority of this mixed blood is flowing down through this aorta specifically the descending aorta now some of that blood is going to go down to the lower extremities and help those out because it's mixed it has some oxygen in it but this descending Horta is when a branch off and it has different branches and we have the internal iliac artery which will connect to our umbilical arteries and again what do the umbilical arteries do there's two of them it can they carry the deoxygenated blood so we're going to take that blood and we're gonna get it back to mama who is going to remove that waste and help replenish it so this cycle will just keep going over and over so now let's talk about how this changes after birth so a baby is born and they saw it breathing on their own what's one of the first things they do after the baby is born they cut the umbilical cord so when we cut the umbilical cord we are stopping this whole transfer of blood flow back and forth so especially with the umbilical vein we do not need the ductus venosus so it disappears now remember the resistance thing I was talking about earlier with the lungs so before baby's breathing on their own and they have fluid in their lungs the resistance is really high in here we're just making the resistance on the right side a lot higher than compared to the left side of the heart but once baby starts breathing they clear all that fluid out of their lungs those sacs pop open the resistance drops so whenever that drops that's going to change the pressure over here on the right side of the heart it's actually going to become a lot lower on the right side compared to the left side so now we don't need that shunting of the blood it's not really gonna happen because we've changed the pressure so this is going to help the frame in ovalle close so you won't have this connection anymore between your right atrium and left atrium because now we need blood to go and do its job like how it does on the right side we need to majority up through this pulmonary artery and hit those lungs now in some people this framin ovalle doesn't close and we call this a patent foramen ovale a PF oh and I have a whole series on congenital heart defects if you want to check out that video that will talk about this along with the patent ductus our Yuriy osis so that closes then we have the ductus arteriosus and this closes we have the pressure changes you're not going to have the high pressure here pulmonary artery allowing it to flow up here into the aorta but we've also removed this placenta the placenta produces prostaglandins and this vessel is really sensitive to prostaglandin so when we cut that out we decrease the prostaglandins that's gonna help close this ductus arteriosus plus the baby's breathing on their own oxygen levels are up and so we don't need that structure anymore and it will still off okay so that wraps up this review over fetal circulation and don't forget to access the free quiz that will test you on this content

Channel: RegisteredNurseRN

Views: 373,547

Keywords: fetal circulation, fetal circulation after birth, fetal circulation nursing, fetal circulation steps, fetal circulation video, fetal circulation before, fetal circulation before and after birth, circulation of fetus, circulation of fetal heart, fetal heart circulation, maternity nursing, maternity nursing lectures, maternity nursing nclex review, fetal shunts of the heart three fetal shunts, fetal circulation nclex, nclex-rn, nclex-pn, nursing

Id: EIfCa0OUbPA

Length: 16min 23sec (983 seconds)

Published: Thu Jan 16 2020