Embryonic Development on Days 11-12 Quiz

• Development on day 11-12 involves the formation of the cytotrophoblast and hypoblast lining the exocoelomic cavity.
• The blastocyst is embedded in the endometrial stroma.
• Lacuna are more developed at the embryonic pole.
• Uteroplacental circulation is established, allowing maternal blood to flow through the trophoblastic system.
• Extraembryonic mesoderm appears, forming fine loose connective tissue between trophoblast and amnion.
• The extraembryonic coelom or chorionic cavity is formed within this tissue.
• Growth of the bilaminar disc is relatively slow.
• The disc remains very small (0.1 to 0.2 mm).
• Decidua reaction begins as cells of the endometrium become pale and loaded with glycogen and lipids.
• Intercellular spaces also appear during the decidua reaction.

Test your knowledge of early embryonic development with this quiz! From the formation of the cytotrophoblast and hypoblast to the establishment of uteroplacental circulation, this quiz covers important milestones in the first few weeks of pregnancy. See if you can identify key terms like blastocyst, lacuna, and extraembryonic mesoderm as you test your understanding of embryonic development.