The thickness of tissue as marked by an arrow in the picture below at the time of implantation is ?
A. 3 – 4 mm.
B. 20 – 30 mm.
C. 15 –20 mm.
D. 30 – 40 mm.
The tissue shown in the picture above represents endometrium.
7he Endometrium is in the secretory phase corresponding to 20 – 21 days of cycle” at the time of implantation.
“After ovulation, the endometrium now demonstrates a combined reaction to estrogen and progesterone activity. Most impressive is that total endometrial height is fixed at roughly its preovulatory extent (5 -6 mm) despite continued availability of estrogen.”
Reading the above text it is clear that endometrium is – 5 – 6 mm thick at the time of implantation, which is not given in the option. Still if you have to mark one answer option ‘a’ i.e. 3 – 4 mm being closest could be right.
- Implantation occurs 7 – 9 days after ovulation°.
- In human, the blastocyst burrows in the uterine cavity till whole of it lies within the thickness of endometrium. This is called as interstitial implantation.
- After implantation of the embryo the uterine endometrium is called the decidua”.
Decidua basalis – The part of decidua where the placenta is to be formed.
Decidua Capsularis – The part of the decidua that separates the embryo from the uterine lumen. Decidua Parietalis – The part of the decidua lining rest of the uterine cavity.
At the end of pregnancy, the decidua is shed off along with placenta and membranes.