K12 Week 2

From Embryology

Week 2

In the second week of development the dividing zygote forms a solid ball of cells and is now called a blastocyst.

  • The cells on the surface of the ball will not form part of the embryo and will go on to make the placenta and membranes that surround the embryo.
  • The cells on the inside form a small clump beside a fluid filled space. This small clump of cells (embryoblast) will form all the parts of the embryo.

During this second week the blastocyst will stick to the inside of the uterus and will no longer float free. This sticking process is required to allow the blastocyst to begin to get food from the mother.

Question: You start as a single cell, how many cells are you now?


Cite this page: Hill, M.A. (2024, April 19) Embryology K12 Week 2. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/K12_Week_2

What Links Here?
© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G