Lect 9. Placenta and Fetal Membranes

Question 1

What are the 2 sides of placenta?

Answer 1

1. Basal plate (maternal side)
2. Chorionic plate (fetal side)

Question 2

2 features of Chorionic plate (fetal side)

• Which side of placenta that Umbilical cord emerges from

Answer 2

1. Chorionic plate (fetal side)

Question 3

2 features of basal plate (maternal side)

Answer 3

• Divided into lobes
• Separated by septa

Question 4

2 features of Chorionic plate (fetal side)

• Contains ____, providing a massive surface for exchange
• ____ emerges from the fetal side of the placenta.

Answer 4

• branching chorionic villi
• Umbilical cord

Question 5

The zygote produced by fertilization undergoes mitotic cleavages as it is moved toward the uterus, with its cells called (1)___ in a compact aggregate called the (2)___.


Answer 5

1. Basal plate (maternal side)
2. Chorionic plate (fetal side)

Question 6

2 membranes of placenta

Answer 6

• Amnion
• Chorion

Question 7

How many vessels that umbilical cord contain?

Answer 7

• 2 arteries: carry deoxygenated fetal blood to the placenta
• 1 vein: carries oxygenated blood back to the fetus

Question 8

The role of umbilical arteries

Answer 8

carry deoxygenated fetal blood to the placenta

Question 9

The role of umbilical arteries

Answer 9

carry deoxygenated fetal blood to the placenta

Question 10

The role of uterine arteries

Answer 10

Bring oxygenated blood to each intervillous space

Question 11

The role of umbilical veins

Answer 11

carries oxygenated blood back to the fetus

Question 12

Placenta blood flow

→ Identify?

Answer 12

Question 13

The role of uterine veins

Answer 13

Take deoxygenated blood from the placenta back to maternal iliac veins

Question 14

PLACENTA BLOOD FLOW

→ IDENTIFY?

Answer 14

Question 15

Fibroblasts become enlarged, polygonal, more active in protein synthesis, and are now called ___

Answer 15

decidual cells.

Question 16

The whole endometrium is now called the decidua


(L. deciduus, falling off, shedding) and includes 3 areas

→ What are they?

Answer 16

1. The decidua basalis between the implanted embryo and the myometrium.

2. The decidua capsularis, the region between the embryo and the uterine lumen which thins as the embryo gets larger.

3. The decidua parietalis, on the side of the uterus away from the embryo.

Question 17

The whole endometrium is now called the decidua


(L. deciduus, falling off, shedding) and includes 3 areas

→ What are they?

Answer 17

1. The decidua basalis between the implanted embryo and the myometrium.

2. The decidua capsularis, the region between the embryo and the uterine lumen which thins as the embryo gets larger.

3. The decidua parietalis, on the side of the uterus away from the embryo.

Question 18

PLACENTA BLOOD FLOW

→ IDENTIFY?

Answer 18

Question 19

Fetal portion of placenta faces to ___ which includes ___

Answer 19

• the amniotic cavity
• amnion, chorionic plate & villi

Question 20

Maternal portion is formed by __

Answer 20

decidua basalis (basal plate) & placental septa.


Question 21

Chorionic villi of the developing placenta go through 3 stages. What are they?

Answer 21

• Primary villi
• Secondary villi
• Tertiary villi

Question 22

Primary villi appear 2 days after implantation as (1)___ covered by (2)___ extend into lacunae containing maternal blood.

Answer 22

1. simple cords of proliferating cytotrophoblast cells
2. syncytiotrophoblast

Question 23

■ Secondary villi begin to form on about the 15th day of embryonic development as the primary villi are invaded by ____

■ Tertiary villi develop within a few more days as ____ differentiates to form capillary loops continuous with the embryonic circulatory system.

Answer 23

• extraembryonic mesenchyme.
• mesenchyme in the secondary villi

Question 24

The whole endometrium is now called the decidua


(L. deciduus, falling off, shedding) and includes 3 areas

1. The decidua basalis between ____
2. The decidua capsularis, the region between the ___ which thins as the embryo gets larger.
3. The decidua parietalis, on ___

Answer 24

1. the implanted embryo and the myometrium.
2. embryo and the uterine lumen
3. the side of the uterus away from the embryo.

Question 25

Identify

Answer 25

Question 26

Placental circulation * ___ provide a large surface area for maternal–fetal exchange.

Answer 26

Chorionic villi

Question 27

The role of Chorionic villi

Answer 27

provide a large surface area for maternal–fetal exchange.

Question 28

The role of Chorionic villi

Answer 28

fill the intervillous spaces in the decidua basalis layer of the endometrium

Question 29

What is Placental barrier?

Answer 29

a selectively permeable membrane separating the maternal and fetal blood.

Question 30

The placental barrier is a selectively permeable membrane separating the maternal and fetal blood. → The barrier is comprised of the 6 layers → What are they?

Answer 30

1. Syncytiotrophoblast 2. Cytotrophoblast 3. Trophoblast basal lamina 4. Extraembryonic mesenchyme 5. Endothelial basal lamina 6. endothelial cells

Question 31

Fetal capillary → IDENTIFY

Answer 31

Question 32

**Fetal Membranes** Placenta initially forms a sphere but as the embryo grows, the placenta thins on the side closest to uterine lumen and the embryo bulges into \_\_\_

Answer 32

uterine cavity

Question 33

1. Edometrium that lines the uterus are called \_\_\_ 2. Endometrium overlying embryo are called \_\_\_

Answer 33

1. Decidua parietalis 2. Decidua capsularis

Question 34

**Fetal Membranes** **→** Identify

Answer 34

Question 35

Fetal membranes → Identify

Answer 35

Question 36

**Fetal Membranes** → Identify

Answer 36

Question 37

**Fetal Membranes** By 3rd month, physiologic herniation of the small intestine has returned to the abdomen and only things in the umbilical cord are umbilical vessels and \_\_\_, supporting cushion of extraembryonic mesoderm

Answer 37

**Wharton’s jelly**

Question 38

**Fetal Membranes** **\_\_\_** that separates the amniotic cavity from the cervix composed of amnion, smooth chorion, endometrium and smooth chorion

Answer 38

**Amniochorionic membrane**

Question 39

**Fetal Membranes** **Amniochorionic membrane** that separates the amniotic cavity from the cervix composed of\_\_\_ (4)

Answer 39

amnion, smooth chorion, endometrium and smooth chorion

Question 40

**Fetal Membranes** **Amniochorionic membrane** that separates ___ from the cervix composed of amnion, smooth chorion, endometrium and smooth chorion

Answer 40

the amniotic cavity