Lect 9. Placenta and Fetal Membranes Flashcards
What are the 2 sides of placenta?
- Basal plate (maternal side)
- Chorionic plate (fetal side)
2 features of Chorionic plate (fetal side)
- Which side of placenta that Umbilical cord emerges from
- Chorionic plate (fetal side)
2 features of basal plate (maternal side)
- Divided into lobes
- Separated by septa
2 features of Chorionic plate (fetal side)
- Contains ____, providing a massive surface for exchange
- ____ emerges from the fetal side of the placenta.
- branching chorionic villi
- Umbilical cord
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)___.
- Basal plate (maternal side)
- Chorionic plate (fetal side)
2 membranes of placenta
- Amnion
- Chorion
How many vessels that umbilical cord contain?
- 2 arteries: carry deoxygenated fetal blood to the placenta
- 1 vein: carries oxygenated blood back to the fetus
The role of umbilical arteries
carry deoxygenated fetal blood to the placenta
The role of umbilical arteries
carry deoxygenated fetal blood to the placenta
The role of uterine arteries
Bring oxygenated blood to each intervillous space
The role of umbilical veins
carries oxygenated blood back to the fetus
Placenta blood flow
→ Identify?
The role of uterine veins
Take deoxygenated blood from the placenta back to maternal iliac veins
PLACENTA BLOOD FLOW
→ IDENTIFY?
Fibroblasts become enlarged, polygonal, more active in protein synthesis, and are now called ___
decidual cells.
The whole endometrium is now called the decidua
(L. deciduus, falling off, shedding) and includes 3 areas
→ What are they?
- The decidua basalis between the implanted embryo and the myometrium.
- The decidua capsularis, the region between the embryo and the uterine lumen which thins as the embryo gets larger.
- The decidua parietalis, on the side of the uterus away from the embryo.
The whole endometrium is now called the decidua
(L. deciduus, falling off, shedding) and includes 3 areas
→ What are they?
- The decidua basalis between the implanted embryo and the myometrium.
- The decidua capsularis, the region between the embryo and the uterine lumen which thins as the embryo gets larger.
- The decidua parietalis, on the side of the uterus away from the embryo.
PLACENTA BLOOD FLOW
→ IDENTIFY?
Fetal portion of placenta faces to ___ which includes ___
- the amniotic cavity
- amnion, chorionic plate & villi
Maternal portion is formed by __
decidua basalis (basal plate) & placental septa.
Chorionic villi of the developing placenta go through 3 stages. What are they?
- Primary villi
- Secondary villi
- Tertiary villi
Primary villi appear 2 days after implantation as (1)___ covered by (2)___ extend into lacunae containing maternal blood.
- simple cords of proliferating cytotrophoblast cells
- syncytiotrophoblast
■ 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.
- extraembryonic mesenchyme.
- mesenchyme in the secondary villi
The whole endometrium is now called the decidua
(L. deciduus, falling off, shedding) and includes 3 areas
- The decidua basalis between ____
- The decidua capsularis, the region between the ___ which thins as the embryo gets larger.
- The decidua parietalis, on ___
- the implanted embryo and the myometrium.
- embryo and the uterine lumen
- the side of the uterus away from the embryo.
Identify
Placental circulation
- ___ provide a large surface area for maternal–fetal exchange.
Chorionic villi
The role of Chorionic villi
provide a large surface area for maternal–fetal exchange.
The role of Chorionic villi
fill the intervillous spaces in the decidua basalis layer of the endometrium
What is Placental barrier?
a selectively permeable membrane separating the maternal and fetal blood.
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?
- Syncytiotrophoblast
- Cytotrophoblast
- Trophoblast basal lamina
- Extraembryonic mesenchyme
- Endothelial basal lamina
- endothelial cells
Fetal capillary
→ IDENTIFY
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 ___
uterine cavity
- Edometrium that lines the uterus are called ___
- Endometrium overlying embryo are called ___
- Decidua parietalis
- Decidua capsularis
Fetal Membranes
→ Identify
Fetal membranes
→ Identify
Fetal Membranes
→ Identify
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
Wharton’s jelly
Fetal Membranes
___ that separates the amniotic cavity from the cervix composed of amnion, smooth chorion, endometrium and smooth chorion
Amniochorionic membrane
Fetal Membranes
Amniochorionic membrane that separates the amniotic cavity from the cervix composed of___ (4)
amnion, smooth chorion, endometrium and smooth chorion
Fetal Membranes
Amniochorionic membrane that separates ___ from the cervix composed of amnion, smooth chorion, endometrium and smooth chorion
the amniotic cavity
