PHGY 209 Lecture Notes - Lecture 3: Yolk Sac, Lymph Node, Bone Marrow

• School: McGill University
• Department: Physiology
• Course: PHGY 209
• Professor: Melissa A Vollrath

Document Summary

Your children make up the characters and your job is to use them in the story. We have all the characters that we need for the story now. A sperm fertilizes an egg and forms a zygote. Everything from that zygote has to make all of you. It multiplies and at the end of the day there are many specialized cells. At the same time as the zygote develops, a yolk sac develops that will feed the embryo. The yolk cell has the stem cells for the entire hematologic system. Those stem cells make their way from the yolk sac to the fetal liver once the liver has developed. In the liver the stem cells do a lot of stuff. Some of the stem cells go to the bone marrow and they can do any of the cells that we require. The myeloid progenitors can make rbcs, megakaryocytes for platelets and wbcs (more important for us).