Reproductive System - Process of Implantation Flashcards
Where is the zygote formed and where is its destination?
The entire phase of the zygote happens within the fallopian tubes (oviduct), and the zygote is being moved by the cillia into the uterus, while rapidly dividing through the process of cell division.
What marks the change of a zygote to a morula.
The process of rapid cell division, 2 cells to 4 cells to 8 cells. Once it reaches 16 cells, it is classified as a morula. After a few days
What is cleavage?
Rapid cell division, due to how fast they are dividing it doesn’t give the individual cells enough time to grow. (A large surplus of small cells without any enlargement.)
How do Identical/Fraternal Twins come to be?
1.) For Identical Twins, this has to happen prior to cell differentiation but it is where the morula spilts into half OR. once the morula comes to be (16) cells, it just keeps dividing.
2.) Fraternal Twins, this happens if two eggs are released upon ovulation and the sperm fertilizes them both.
What is the embryo called after 6-7 days after fertilization? What are the different types and its functions?
A blastocyst. (A hollow structure to which new cellular structures can develop in)
Trophoblast is the outer layer of the blastocyst (formed inside a memberane called chorion which will eventually be apart of the placenta.) Inner cell mass (what will become the embryo and fetus), and the blastocoel which is the fluid filled space.
What is the function of the placenta?
The placenta provides nutrients and oxygen to the developing embryo as well as removes its wastes through the process of diffusion.
For pregnancy to occur, what to hormones are VITAL.
Estrogen and progesterone. Estrogen and progesterone need to be secreted to prevent uterine contractions or it will harm the developing embryo.
What hormone assists with the secretion of these hormones?
hCG (Human Choronic Gonadtropin Hormone), released by the chorion from the trophoblast.
3 Functions of hCG
1.) Keep the corpeus luteum in tact to continue secreting estrogen and progesterone.
2.) Maintain the endometrium
3.) Prevent menstruation.
hCG levels stay high till….when and why
hCG levels stay high within the first 2 months of the pregnancy but then slowly decline due to rising presence of the placenta. The corpeus luteum will remain intact throughout the entire pregnancy but the usage of its hormones will severely decline as the placenta will start making a sufficient amount of estrogen and progesterone.
What also happens on day 6-7 after fertilization what does the chorion grow?
It grows villi and implants into the endometrium of the uterus.
After the chorion implants the blastocyst into the uterus what happens?
The blastocyst digests/sinks its way through the endometrium into a pool of the moms blood and tissues where it can now be nourished and remove its wastes through the process of diffusion.
