Embryogenesis II- we finish up the embryology review by going over gastrulation, neurulation, and getting into a discussion on the germ layers, teratogens, stem cells, and fetal circulation. Hey, hey, hey - It’s Nikaela, and this is Cellfie Life. Where we talk about complex science principles by relating them to, I love lucy episodes and bunnies.  If you have no idea what I’m talking about listen to the Early Embryogenesis episode, it was the episode right before this one. Also, For those of you questioning my three heys, I heard someone say it in the library when I was writing this episode and thought I would try it on. I’m not sure how I feel about it.  Hi, I'm Nikaela welcome to the Cellfie Life. This subject is a two-parter because it was getting a little longer than I wanted. I want to keep these episodes around 30 minutes-ish. So, I decided to chop the Embryogenesis review in half.  But first housekeeping! I have set up a Patreon page; If you are enjoying the show and want to share the love, you can head over to pateron.com. With Patreon, you can pay a small amount of money each month to help me cover production costs. It will help me pay for hosting and pay my amazing editors that help me get these episodes out every week. You can support the podcast for as little as .25 cents an episode, a dollar a month. Or if you are just such a broke student and you need that dollar for ramen, I get it, share the love by telling your friends about this podcast, and rating and reviewing.  https://www.patreon.com/cellfielife You can follow me on Instagram. I post review questions on my stories just about every day or check out the website at cellfielife.com, where you can find the script notes and the gifs and memes and youtube links I talk about in the show.  Now, let's jump right in-  Okay, so the last episode we talked about fertilization and implantation, and cleavage and morulas, and blastocysts and the trophoblasts and the inner cell mass. And how the inner cell mass gives rise to the bilaminar disk, which ultimately gives rise to the germ layers. I know we covered a lot.  And this is where we are going to pick up on this episode. We are going to pick up right after implantation. The embryo is just heading into gastrulation at this point, which we have already talked about a little in the previous episode, but we're going to talk about it more in detail here. Gastrulation is the formation of the three germ layers. It also happens about the 3rd week of development, so it happens pretty early.  We haven't gone over these germ layers, but do you remember them from school…? Q: What are the three layers of the trilaminar disk called? A: Ectoderm, Mesoderm, Endoderm. If you got that one give yourself a high five- Follow up: Where do these three layers develop from? A: the inner cell mass that forms the bilaminar disk, which is made up of the epiblast and hypoblast. The epiblast layer will become the trilaminar disk, which is made up of ectoderm, mesoderm, and endoderm.  Let’s talk about how these three layers form. We will start by taking another look at the bilaminar disk just to remind us where we’re at; the bilaminar disk has formed and is the two pancakes, remember? The top layer is the epiblast, and the bottom layer is the hypoblast.