Pregnancy Vivian | 07 Apr 2011 03:39 am
Pregnancy Week 2 – How the Fertilized Egg Develops
The migrated cells, in pregnancy week 2, known as the blastocyst will have firmly attached itself with finger-like projections to the wall of your womb by now, after arriving via the fallopian tube.. The globular shaped blastocyst is made up of 2 layers – an external and inner layer (comparable to an egg having an outer shell and an inner yolk).
The inner layer develops into the embryo (known as the embryoblast) and the external layer develops into the embryo’s support system (known as the trophoblast).
The early embryo’s support system includes:
- A amniotic sac to protect the embryo
- The chorion and chorion villi which are responsible for keeping the embryo firmly attached to the side of the uterus.
- The Yolk Sac to provide sustenance until the placenta takes over at the end of the embryonic phase
The inner ‘yolk’ part of the blastocyst (that forms the embryo) will divide into 3 separate layers, known as ‘germ layers’. Each layer is given a specific, unchangeable function that will be responsible for the growth of a specific set of bodily organs in the baby.
Every solitary duplicating cell will also be programmed with genetic coding that will contain 23 chromosomes from both the mother and the father, a sum of precisely 46 chromosomes within each and every cell. These chromosomes make up the baby’s inherited blueprint and will determine their colorings and bodily features. If there is any distortion in the number of chromosomes the baby has then they will be known to have a genetical defect which can be determined by a number of individual tests that are usually carried out at the end of the embryonic phase.