Embryology 1 (Early Stages)

Question 1

What do fimbria do?

Answer 1

During ovulation, they sweet the oocyte into the ampulla where it may be fertilized.

Question 2

Where does a developing embryo typically implant?

Answer 2

The posterior wall of the uterus

Question 3

Where does fertilization typically take place?

Answer 3

Ampulla

Question 4

What is the Zona Pellucida?

Answer 4

Sphere of maternal tissue that surrounds the very early developing embryo (Morula). Made of glycoproteins.

Question 5

Who is a really awesome guy in our class?

Answer 5

Kyle

Question 6

The morula includes two primary parts. What are their names?

Answer 6

The Trophoblast and the Inner Cell Mass

Question 7

What is Early pregnancy factor?

Answer 7

An Immunosuppressant secreted by trophoblast cells that turns pregnancy tests positive.

Question 8

How does the early embryo derive nourishment?

Answer 8

Absorption of secretions from uterine glands

Question 9

What are of the embryo typically first attaches to the uterus?

Answer 9

The embryonic pole

Question 10

When becoming a blastocyst, the trophoblast forms two distinct layers. What are they?

Answer 10

The cytotrophoblast (inner layer) and syncytiotrophoblast (outer layer)

Question 11

Label

Answer 11

Question 12

What level of the embryo invades the uterus?

Answer 12

Syncytiotrophoblast

Question 13

What is thought to activate the clavage stage in the blastomere?

Answer 13

Early Pregnancy Facter (EPF)

Question 14

What is the name of the fluid filled space on the inside of a blastomere?

Answer 14

Blastocoele

Question 15

Following implantation, the row of cells facing the blastocoele become this layer

Answer 15

Embryonic endoderm

Question 16

What cell layer comprises the primitive endoderm?

Answer 16

The Hypoblast

Question 17

The invasion of the syncytiotrophoblast allows what to begin to occur?

Answer 17

Nourishment from maternal tissues

Question 18

By the end of the 2nd week, the synytiotrophoblast begins to produce what hormone?

Answer 18

Human chorionic gonadotropin

Question 19

What is the amniotic cavity?

Answer 19

A cavity at the embryonic pole between the ICM and the cytotrophoblast

Question 20

What cells line the amniotic cavity? What layer do they differentiate from?

Answer 20

The Amnion. The Cytotrophoblast.

Question 21

The ICM forms a flattened disc with what two layers?

Answer 21

Epiblast (amniotic side) and Hypoblast (in blastocyst cavity)

Question 22

During week two of development, what cells line the bastocoele?

Answer 22

Cells from the hypoblast, which form Heuser’s membrane

Question 23

What layer develops into the extraembryonic mesoderm? Where is this membrane located?

Answer 23

Cytotrophoblast. Aroudn the outside and btw the amnion and yolk sac.

Question 24

Cavities in the extraembryonic mesoderm. These coalesce to to form what structure?

Answer 24

Extraembryonic coelom.

Question 25

Lacunar networks in the syncytiotrophoblast combine to form what?

Answer 25

Sinusoids, the basis of primitive circulation

Question 26

What is the chorion?

Answer 26

Extraembryonic somatic mesoderm and two layers of trophoblast?