Bilaminar Germ Disc

Question 1

At the__ of development, the blastocyst is partially embedded in the endometrial stroma.

Answer 1

Eighth day

Question 2

In the area over the 💡embryoblast, the 💡trophoblast has differentiated into two layers:

Answer 2

Cytotrophoblast

Syncytiotrophoblast

Question 3

It is an 💡inner layer of 💡mononucleated cells in the trophoblast.

Answer 3

Cytotrophoblast

Question 4

It is an 💡outer multinucleated zone 💡without distinct cell boundaries in the trophoblast.

Answer 4

Syncytiotrophoblast

Question 5

__ are found in the cytotrophoblast but not in the syncytiotrophoblast.

Answer 5

Mitotic figures

Question 6

Cells of the 💡inner cell mass or 💡embryoblast also differentiate into two layers:

Answer 6

Hypoblast layer

Epiblast layer

Question 7

It is a layer of 💡small cuboidal cells adjacent to the 💡blastocyst cavity which is seen at embryoblast.

Answer 7

Hypoblast layer

Question 8

It is a layer of 💡high columnar cells adjacent to the 💡amniotic cavity which is seen at embryoblast.

Answer 8

Epiblast layer

Question 9

Together, the hypoblast and epiblast layer form a 💡flat disc which is called?

Answer 9

Bilaminar Germ Disc

Question 10

Epiblast cells adjacent to the 💡cytotrophoblast are called?

These cells together with the rest of the epiblast, they line the amniotic cavity.

Answer 10

Amnioblasts

Question 11

It is a 💡small cavity appears within the epiblast. This cavity 💡enlarges to become the __.

Answer 11

Amniotic cavity

Question 12

It is a cell that consists of an 💡inner layer with mononuclear cells, the cytotrophoblast, and an 💡outer layer without distinct cell boundaries, the syncytiotrophoblast.

Answer 12

Trophoblast

Question 13

It is a cell that is formed by the 💡epiblast and 💡hypoblast layers.

Answer 13

Embryoblast

Question 14

The blastocyst is more 💡deeply embedded in the endometrium, and the 💡penetration defect in the surface epithehum is closed by a 💡fibrin coagulum

Answer 14

Day 9

Question 15

It is a phase of trophoblast development where 💡vacuoles appear in the syncytium. When these vacuoles fuse, they form 💡large lacuna.

Answer 15

Lacunar stage

Question 16

It is where 💡vacuoles appear in the syncytium.

Answer 16

Embryonic pole

Question 17

It is where 💡flattened cells probably originating from the 💡hypoblast form a thin membrane, the 💡exocoelomic (Heuser) membrane.

Answer 17

Abembryonic pole

Question 18

It is a 💡thin membrane that lines the 💡inner surface of the cytotrophoblast

Answer 18

Exocoelomic (Heuser) membrane

Question 19

Exocoelomic (Heuser) membrane, together with the hypoblast, forms the lining of the __.

Answer 19

Exocoelomic cavity, or Primitive yolk sac.

Question 20

By the __ of development, the blastocyst is 💡completely embedded in the 💡endometrial stroma, and the surface epithelium aknost entirely covers the original defect in the uterine wall

Answer 20

llth to the 12th day

Question 21

These 💡 capillaries, which are 💡congested and 💡 dilated because cells of the syncytiotrophoblast penetrate deeper into the stroma and 💡 erode the endothelial lining of the maternal capillaries.

Answer 21

Sinusoids

Question 22

It is established when the 💡syncytial lacunae become continuous with the sinusoids, and 💡 maternal blood enters the lacunar system. As the trophoblast continúes to erode more and more sinusoids, maternal blood begins to flow through the trophoblastic system.

Answer 22

Uteroplacental circulation

Question 23

Cells derived from 💡yolk sac cells form a fine, 💡 loose connective tissue, which eventually fills all of the space between the trophoblast externally and the amnion and exocoelomic membrane internally.

Answer 23

Extraembryonic mesoderm

Question 24

It is a 💡new space form when 💡 large cavities develop in the extraembryonic mesoderm become confluent.

This space surrounds the 💡primitive yolk sac and amniotic cavity, except where the germ disc is connected to the trophoblast by the connecting stalk

Answer 24

Extraembryonic cavity, or Chorionic cavity

Question 25

It is the 💡extraembryonic mesoderm lining the 💡 cytotrophoblast and 💡 amnion

Answer 25

Extraembryonic somatic mesoderm

Question 26

It is the 💡extraembryonic mesoderm lining covering the 💡yolk sac.

Answer 26

Extraembryonic splanchnic mesoderm

Question 27

Cells of the endometrium, meanwhile, become polyhedral and loaded with glycogen and lipids; intercellular spaces are filled with extravasate, and the tissue is edematous.

These changes, known as the __.

Answer 27

Decidua reaction

Question 28

By the __ of development, the 💡surface defect in the endometrium has usually 💡 healed. Occasionally, however, 💡 bleeding occurs at the implantation site as a result of 💡 increased blood flow into the lacunar spaces. Because this bleeding occurs 💡 near the 28th day of the menstrual cycle, it may be confused with normal menstrual bleeding and, therefore, may cause inaccuracy in determining the expected delivery date.

Answer 28

13th day

Question 29

These are 💡cellular columns with the syncytial covering.

Answer 29

Primary villi

Question 30

As the hypoblast produces 💡additional cells that 💡migrate along the inside of the exocoelomic membrane. These cells 💡proliferate and gradually form a new cavity within the exocoelomic cavity.

Answer 30

Secondary yolk sac or Definitive yolk sac

Question 31

What is the difference of the secondary yolk sac to primitive yolk sac.

Answer 31

It is much smaller

Question 32

These are formed due to large portions of the exocoelomic cavity are 💡pinched off and which are often found in the 💡 extraembryonic coelom or 💡 chorionic cavity

Answer 32

Exocoelomic cysts

Question 33

It is a 💡large cavity that is formed as the 💡extraembryonic coelom expands.

Answer 33

Chorionic cavity

Question 34

The 💡extraembryonic mesoderm 💡lining the inside of the cytotrophoblast is then known as the __.

Answer 34

Chorionic plate

Question 35

The 💡only place where extraembryonic mesoderm 💡traverses the chorionic cavity is in the __.

Answer 35

Connecting stalk

Question 36

With development of blood vessels, the connecting stalk becomes the __.

Answer 36

Umbilical cord

Question 37

It is a hormone secreted by 💡syncytiotrophoblast cells that quantities of this hormone are sufficient to be detected by the 💡 end of the second week.

Answer 37

Human Choríonic Gonadotropin (hCG)

Question 38

A shift from cell-mediated immunity to humoral (antibody-mediated] immunity occurs and that this shift protects the embryo from rejection.

Answer 38

True

Question 39

-

Answer 39

Placenta previa

Question 40

It is an implantation that takes place outside the uterus.

Sites: abdominal cavity, ovary, or uterine tube

Answer 40

Extrauterine pregnancy, or Ectopic pregnancy.

Question 41

In the abdominal cavity, the blastocyst most frequently attaches itself to the peritoneal lining of the __.

Answer 41

Rectouterine cavity, or pouch of Douglas

Question 42

It is a condition where the 💡trophoblast develops and forms placental membranes, although little or no embryonic tissue is present.

Moles secrete 💡high levels of hCG and may produce benign or malignant (invasive mole, choriocarcinoma] tumors.

Answer 42

Hydatidiform mole

Question 43

This phenomenon, in which there is 💡differential modification and/or expression of homologous alleles or chromosome regions depending on the parent from whom the genetic material is derived.

Answer 43

Genomic imprinting