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Uterine inversion

Visit us (http://www.khanacademy.org/science/healthcare-and-medicine) for health and medicine content or (http://www.khanacademy.org/test-prep/mcat) for MCAT related content. These videos do not provide medical advice and are for informational purposes only. The videos are not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read or seen in any Khan Academy video. Created by Nauroz Syed.

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  • primosaur ultimate style avatar for user Skyler S
    how long is the umbilical cord?
    (1 vote)
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  • duskpin ultimate style avatar for user BlackKowfee
    What is the placenta made of?
    (2 votes)
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    • boggle purple style avatar for user lily J
      Here's what I got from google:
      The placenta begins to develop upon implantation of the blastocyst into the maternal endometrium. The outer layer of the blastocyst becomes the trophoblast, which forms the outer layer of the placenta. This outer layer is divided into two further layers: the underlying cytotrophoblast layer and the overlying syncytiotrophoblast layer. The syncytiotrophoblast is a multinucleated continuous cell layer that covers the surface of the placenta. It forms as a result of differentiation and fusion of the underlying cytotrophoblast cells, a process that continues throughout placental development. The syncytiotrophoblast (otherwise known as syncytium), thereby contributes to the barrier function of the placenta.

      Hope that helps!
      (1 vote)

Video transcript

- It's funny. I remember in the very first delivery I ever attended, right after the baby was delivered and the umbilical cord was cut, I started to unscrub and remove my gloves. And then I heard someone yell out, "Hey, where you going? "We still have to deliver the placenta." So they were right. The delivery of the baby is followed by the delivery of the placenta, which usually occurs within five to 15 minutes. But it shouldn't take longer than 30 minutes. After 30 minutes, you start to think that something might be wrong. And, as you're standing there, with your hand gently, very gently, holding on to the umbilical cord, there are four key signs that you look out for that signal that the placenta is separating from the wall of the uterus. So let's talk about what those four signs are. The first is that the umbilical cord lengthens. And that makes sense. The umbilical cord is attached to the placenta. And if the placenta is detaching from the uterus, more of the umbilical cord should appear in front of you. So that's the first sign, that the umbilical cord, the umbilical cord, umbilical cord lengthens. The umbilical cord lengthens. The second sign is a gush of blood. The second sign that the placenta is separating from the wall of the uterus is a gush of blood. Which, if you can visualize it, the placenta is shearing away from the underlying endometrium. And that shear rips apart blood vessels, causing the bleeding to occur. And all of this is happening spontaneously. How? Well, after the baby is delivered, the uterus shrinks in size, because the uterus is muscle, after all. So it has the ability to stretch and shrink really rapidly. But the placenta isn't a muscle. It doesn't change shape as ready. So as the uterus shrinks and kind of retracts away, the blood vessels in the placenta tear. So that accounts for the bleeding. Now, to understand the third and the fourth signs of placental separation, you have to understand what I think is the absolute most amazing thing about the uterus and the placenta, and that is the structure with which the muscle fibers of the uterus are arranged. So, the muscle fibers of the uterus are arranged in a kind of criss-cross fashion around the blood vessels. So, here you have the muscle fibers of the uterus, and they're arranged kind of in a criss-cross fashion, kind of like, kind of like a lattice around the blood vessels. So when the uterus contracts, it squeezes on these blood vessels, which have now been sheared and ruptured, to stop the bleeding. Without this feature, the mom would probably die of a hemorrhage from the separation of the placenta. But the uterus contracting down on these blood vessels stops the bleeding. And the third and fourth signs are related to that contraction of the uterus. So you feel, the third sign is that you feel, the uterus feels firm and globular. So you can actually feel that it's firming up and that it's more globular, globular in shape, right? And you also, the fourth sign is that you're able to feel the uterus rising up to the anterior abdominal wall. So you actually feel the uterus contracting and sort of pushing up, or rising up, to the anterior abdominal wall. So why am I going into so much detail about these signs? Well, it's because we look for them, we wait for them. Because when they all occur, we know that the placenta is coming and we can sort of help the process out. But sometimes a practitioner can put too much pressure on the umbilical cord too early, that is, when the placenta is still firmly attached to the uterus. And that can lead to inversion of the uterus, or the uterus sort of turning inside out and coming out through the vagina. And that kind of looks like this. The uterus is kind of turned inside out because you pulled on the umbilical cord too hardly. And the best way to prevent this from happening is to wait til all four signs, not two, not three, but all four signs of placental separation occur before you put any traction on the umbilical cord. But if the uterine inversion does occur, the very first step is to try to reposition the uterus back into its normal position. And that can be pretty challenging because the uterus is in a contracted position, right? It's contracted, and that makes it harder to manipulate. So that's why I will often start off by using uterine relaxing agents, so, uterine relaxation agents to first, sort of, relax the uterus, make it softer, more pliable. And then, after the uterus is relaxed, the practitioner will then place the uterus back into its normal position. And after the uterus is placed back into its normal position, we'll usually follow this with a uterine contracting agent, or what's called a uterotonic agent, right? So "utero" meaning "uterus," "tonic" meaning "tone," "contraction," right? So uterotonic agent. And the uterotonic agent helps to limit the bleeding, because, again, when the uterus contracts down, it squeezes off those blood vessels that are running through it. And it also helps, the uterotonic agent also helps to prevent reinversion of the uterus. So that's why we use it. Now, another thing, this also very important to keep in mind, is that uterine inversion can be accompanied by a lot of bleeding. So volume replacement, sort of blood volume replacement, is a very central part of treatment. So before we finish off this topic, I wanna mention a couple of things that put a woman at risk for uterine inversion. I already mentioned that putting too much traction on the umbilical cord is one huge, major risk factor. Another thing that makes uterine inversion a lot more likely is having a placenta that's too firmly attached to the uterus. And you can imagine, the placenta's too firmly attached to the uterus, and that makes you, that would probably make a person pull on the umbilical cord too hardly, right? And that condition, where the placenta is attached too firmly to the uterus, is called placenta, it's called placenta, placenta accrea, right? Or very firmly adherent placenta. And you can also probably imagine that having a floppy uterus makes it easier to invert. So use of uterine relaxing agents can also increase the risk of inversion. Okay. So that's uterine inversion in a nutshell, a condition that teaches us to be, or reminds us to be, patient and to remember that, even though the umbilical cord may look like a rope, we're not playing tug-of-war with the placenta.