embryo- 2nd wk devt

Day 8

Trophoblast differentiated into two layers:

1. inner layer of monucleated cells, the __________

2. outer layer, the __________

Embryoblast of inner cell mass differentiates into

2 layers:

1. __________ layer adjacent to blastocyst cavity

2. __________ layer adjacent to amniotic cavity

Day 8

Together, the epiblast and hypoblast form the ___________

The epiblast cells lining the amniotic cavity, which is adjacent to your cytotrophoblast, are called your ___________

Day 9

Blastocyst more deeply embedded in endometrium

Trophoblast shows progress in development, vacuoles appear, fuse forming large lacunae, this phase is known as the __________

Days 11 and 12

Blastocyst completely embedded in endometrium

Maternal blood begins to flow through the trophoblastic system, establishing the ________ circulation.

Extraembryonic mesoderm splits into 2 layers:

1. ________ - membrane lining cytotrophoblast

2. ________ - lining near blastocyst (exocoelomic) cavity; future yolk sac

The vacuoles and cavities in between the somatic and splanchnic membrane extraembryonic cavity (later on will be called the ________ cavity/________ cavity).

Day 13

Bleeding occurs at implantation site as a result of increased blood flow into the lacunar spaces, occurs near the 28th day of menstrual cycle.

Ovulation occurs on the 14th day. So if implantation occurs, it would be either on the 12th or 13th day from the day of ovulation. Meaning, it occurs on Day 26 or 27, near the 28th day. If there is bleeding at those times, it is more likely implantation bleeding, not abortion or menstruation.

• This information can be used as basis for counting the _______ menstrual period of implantation.

Day 13

Hypoblast produces additional cells, which is the

_________ yolk sac or definitive yolk sac

Connecting stalk with development of blood vessels will be the ________

Aside from the formation of extraembryonic membranes

or ________ layer, you also form two cavities:

________ cavity (formed after Extraembryonic coelom expands) and ________ cavity.

Summary:

The second week of development is known as the __________

1. The trophoblast differentiates into two layers: the __________ and __________

2. The embryoblast forms two layers: the __________ and __________

3. The extraembryonic mesoderm splits into two layers: the __________ and __________ layers.

4. Two cavities form: the __________ and __________ cavities.

Menstrual cycle have three phases:

(1)

(2)

(3)