Implantation - pre-embryonic development, Biology

Assignment Help:

Implantation - Pre-Embryonic Development

After entering the uterus and formation of ICM, the blastocyst starts to embed in the endometrium of the uterine wall. By one week after fertilization the trophoblast secretes enzymes which digest the tissues and blood vessels of the uterine wall. The invading trophoblast differentiates into two layers, the outer syncytiotrophoblast and the inner cellular layer. Like the syncytiotrophoblast swallows more blood vessels in the uterine wall lacunae develop in the syncytiotrophoblast that get filled up with blood from the mother and exchange of gases takes place here. So a primitive utero- placental circulation is established. This nourishes the embryo till the placenta is made. By the 10th day the blastocyst is totally embedded in the uterine wall.

This kind of implantation in which the embryo gets fully embedded is termed as interstitial implantation. The trophoblast begins to secrete human chorionic gonadotropin (HCG). HCG causes the corpus luteum to be maintained and to carry on to secrete estrogen and progesterone. Sometimes implantation may occur outside the uterus at some other location. In that case it is an ectopic pregnancy. The implantation site might be the fallopian tube or even the abdominal cavity. In ectopic pregnancy the embryo has to be surgically removed as if it is not done, it can lead to tuba1 rupture, internal bleeding, shock and possible death. At the beginning of the second week a small cavity appears between the trophoblast and ICM. This is the amniotic cavity that will grow around the embryo and later the foetus, It is a fluid filled cavity that act as an insulator against shocks, cold and heat. At similar time the ICM also differentiates into two layers, the upper epiblast which provides rise to the embryo and the lower hypoblast which gives rise to the extraembryonic membranes.


Related Discussions:- Implantation - pre-embryonic development

Guidelines for the family members for healthy coping, Q. Guidelines for the...

Q. Guidelines for the Family Members for Healthy Coping? - Patient and the family members should discuss the situation, change in role,time distribution, share of money and oth

Explain methods of protein estimation, Explain Methods of Protein Estimatio...

Explain Methods of Protein Estimation? Several methods for protein estimation are available. These methods are based on several analytical characteristics of the protein. Labor

Ross operation-surgical techniques, Ross Operation :  In this technic...

Ross Operation :  In this technically demanding operation, the aortic valve is replaced by patient's own pulmonary valve (autograft) and a pulmonary or aortic allograft (homo

Define some texturization processes, Known physicochemical basis of some of...

Known physicochemical basis of some of these texturization processes are presented below: 1.Thermal Coagulation and Film Formation: Concentrated soy proteins can be thermally

Determine the blood plasma levels of oxytocin, Which of the following serve...

Which of the following serves as an actuating signal, or as part of an actuating signal, in a system with feedback? (Either positive feedback or negative feedback) A. Blood pla

What percentage of the father''s body was covered by burns, The Jones famil...

The Jones family was caught in a fire but escaped. Unfortunately the father and daughter suffered burns. The father had second degree burns on his chest, abdomen, and both arms, an

Define nutrition and sports - physical fitness of an athlete, Define Nutrit...

Define Nutrition and Sports - Physical Fitness of an athlete? The physical fitness and performance of an athlete is affected by both current and previous nutritional status. T

Difference between that is alive, Is there a difference between something t...

Is there a difference between something that is alive and something that is a living organism?

What is the function other than protection of the ribs, What is the functio...

What is the function, other than protection, of the ribs? The ribs help to alter the volume of the thorax during breathing movements.

Electron transport , 1) It is the series of coupled oxidation/reduction rea...

1) It is the series of coupled oxidation/reduction reactions where the electrons are passed like hot potatoes from one membrane-bound protein/enzyme to another before being finally

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd