This episode is the second part of a series on embryogenesis, which is the formation and development of an embryo in the first eight weeks.



The episode picks up right after implantation. It covers the formation of the three germ layers: ectoderm, mesoderm and endoderm. These germ layers give rise to different tissues in the body.



Neurulation is the process where the neural tube forms. The neural tube will later form the brain and spinal cord.



The episode also talks about teratogens, which are things that can interfere with development and cause defects. Some examples of teratogens include alcohol, environmental chemicals, and viruses.



Stem cells are also discussed. Stem cells are cells that can differentiate into many different types of cells. The episode talks about the different types of stem cells and how they differentiate.



The last topic covered in the episode is fetal circulation. Fetal circulation is different from adult circulation because the fetus is not using its lungs to take in oxygen. The fetus gets its oxygen from the mother through the placenta.



I have the script notes from all the episodes, so if you want to print out and use them to aid in your studying, the transcripts are available under the episodes. Download the full transcript!