Establishing Pregnancy: Embryogensis, Maternal Recognition of Pregnancy, Implantation, and Placentation

What must the conceptus provide to advance beyond the blastocyst stage?

A signal to maintain maternal production of progesterone and form a placenta.

What is a prerequisite for maternal recognition of pregnancy?

Development of the trophectoderm.

What role do maternal recognition signals play during pregnancy?

They prevent/delay luteolysis by interfering with PGF2alpha-induced regression of the corpus luteum.

How can placentas be classified?

Based on the distribution of chorionic villi and the histology of the interface between maternal-fetal tissues.

What is embroyogenesis?

The process by which the zygote transforms into an embryo.

What is the function of progesterone during pregnancy?

It sustains pregnancy in the uterus and maintains the corpus luteum.

Which animal species is known as an induced ovulator?

Rabbits and cats.

What is the pregnancy recognition signal in cows?

Bovine interferon-t (bIFN-t).

What method do swine use for maternal recognition of pregnancy?

Estradiol produced by the porcine blastocyst.

What is the role of the trophoblast in early pregnancy?

It gives rise to the membranes that become the placenta.

What defines the luteal-placental shift?

The decline of progesterone produced by the corpus luteum as the placenta takes over its production.

What strategy does the conceptus use to evade maternal immune responses?

It employs diversionary tactics to act as an invading parasite.

Describe the process of implantation.

It requires the embryo to develop to the blastocyst stage and the uterus to be in a state that favors implantation.

What are the two stages of embryo attachment to the uterus?

Apposition and adhesion.

What occurs during decidualization in pregnancy?

Stromal cells and endothelial cells transform into decidual cells, forming part of the maternal placenta.

Fill in the blank: The process by which the zygote transforms into an embryo is known as __________.

embryogenesis.

What occurs during decidualization in pregnancy?

Stromal cells and endothelial cells transform into decidual cells, forming part of the maternal placenta.