For the next three months, I’ll be blogging about fetal development! Yes!! I know some of you might be like “Cassie, I don’t really care. I just support life and I don’t really need to know about that.” But I’m here to tell you that this stuff is actually super cool. Here’s how it’s going to go down:
So let’s start from the very beginning (a very good place to start). We’ll be tracking the development of baby Jacob (he’s an imaginary baby). The moment of conception is the beginning of Jacob’s life. In that moment, he is the smallest he will ever be, and will naturally develop by himself. It’s important to place the beginning of life at this point.
18 days after conception, Jacob’s heart begins to beat. 21 days after conception, his heart is pumping blood.
By week 4, a yolk sac is already supplying fetus Jake with red blood cells.
Week 6 is a big one! It means Jacob has developed leg buds, which are shaped like little paddles with webbing between his toes, that will turn into his legs. He’ll be moving his legs around later this week! (He’s got Olympic goals, so he has to start early). Jake also has a heart bulge, which is beating two times as fast as his mother’s, and it is beginning to split into left and right chambers. Jacob’s brain waves are detectable. His vocal chords and tongue are beginning to form inside his developed jaw. Jacob also has arm buds, that look similar to his leg buds, and he’ll move his arms later this week as well. Jake’s eye spot is beginning to form this week. He is still only the size of a pomegranate seed.
By week 8, Jacob’s nerve cells in his brain are beginning to form primitive neural pathways. His hands are flexed and rest over his beating heart. Jake’s fingers are growing longer. He has knee joints, and his legs extend upward to meet the front of his body.
At week 10, Jacob is about an inch and a half tall. His brain is large in proportion to the rest of his body. Jacob is beginning to make his own red blood cells with his liver, so the yolk sac begins to disappear. His fingers have completely separated, and his fingernails are beginning to grow. Jake is about the size of a kumquat.
Jacob’s ears are close to their final position on his head at week 12. A fine layer of hair covers most of his body. Jake is almost three inches long, about the size of a passion fruit.