NOTE:👀 For a better view, tap/click the image to zoom and read all details.
EMBRYOLOGY
MED X – Simplifying Embryology Clinicals and Making Them a Piece of Cake for EVERY MBBS Students. 🧠✨👇👇👇JOIN CHANNEL👇👇👇
https://whatsapp.com/channel/0029VbC9yVWCHDyg9GeqFV0B
CHAPTER 4:Second Week of Development :Bilaminar Germ Disc.
Clinical Correlates
Abnormal Implantation
1. Hormone Production During Implantation
Role of Syncytiotrophoblast
The syncytiotrophoblast is responsible for hormone production during early pregnancy.
The most important hormone produced is:
Human Chorionic Gonadotropin (hCG)
Detection of Pregnancy
By the end of the second week, the level of hCG becomes detectable.
Detection method:
Radioimmunoassay
This forms the basis of pregnancy testing.
2. Maternal Immune Response During Pregnancy
Genetic Composition of the Embryo
50% of the embryo’s genome is paternal.
Therefore:
The embryo is technically a foreign body FOR MORE🚀📚 Want the COMPLETE NOTES of CHAPTER 4 – EMBRYOLOGY
🎯 Get the Full High-Yield Notes FREE of Cost! 💯📖
👇👇 Click the Download Button Below ⬇️⬇️
💎 Don’t miss it — Download Now and Boost Your Embryology Prep! 🚀📥
Tap/Scan Your Favorite Platform & Start Learning Today! 🔗�
The second week of embryonic development (days 8–14) is a crucial phase characterized by the formation of the bilaminar germ disc and important supporting structures. It is commonly referred to as the “week of twos” due to the appearance of paired structures.
The embryoblast differentiates into two distinct layers: the epiblast and the hypoblast, forming the bilaminar germ disc. The epiblast gives rise to the amniotic cavity, while the hypoblast contributes to the formation of the yolk sac.
Simultaneously, the trophoblast differentiates into cytotrophoblast and syncytiotrophoblast. The syncytiotrophoblast invades the endometrium and forms lacunae, which later establish uteroplacental circulation. This layer also secretes human chorionic gonadotropin (hCG), essential for maintaining pregnancy.
The amniotic cavity develops above the epiblast, lined by amnioblasts, while the primary yolk sac forms below the hypoblast. Extraembryonic mesoderm develops and splits to create the chorionic cavity (extraembryonic coelom), which surrounds the embryo and its associated structures.
The connecting stalk, which later forms the umbilical cord, anchors the embryo to the trophoblast. These coordinated processes ensure proper implantation and support for the developing embryo.
These notes provide a structured overview of key events, layers, and clinical correlations, making them ideal for quick revision and high-yield exam preparation.
For more posts like this just click on the below topics: