[PF1] ENDOCRINE - Placenta

What organ contains chorionic villi and maternal blood pooled in spaces of decidua?

Placenta

What does the placenta produce aside from estrogen and progesterone?

hCG, lactogen, relaxin, growth factors

Which cells produce hCG in the placenta?

Syncytiotrophoblast cells

From which part of the embryo is the embryonic part (chorion) of the placenta derived?

Trophoblast

From which part of the uterus is the maternal part of the placenta derived?

Decidua basalis

What is the difference between a mature and an immature placenta?

Presence of blood vessels

What is the inner trophoblast layer of the placenta called?

Cytotrophoblast

What is the outer trophoblast layer of the placenta called?

Syncytiotrophoblast

What do syncytiotrophoblasts project into in the placenta?

Blood-filled lacunae in the decidua

Site of nutrient, gas, and electrolyte exchange between a mother and fetus; also functions in transmission of maternal antibodies - Placenta

Contains chorionic villi (surrounded by two trophoblast layers: cytotrophoblasts and syncytiotrophoblasts) which project into blood-filled lacunae of the decidua – placenta

What hormones are secreted by the placenta?

Human chorionic gonadotropin (HCG), progesterone, estrogen

Which cells lining the chorionic villi are located on the outer layer?

Syncytiotrophoblasts

Which cells lining the chorionic villi invade the stroma?

Syncytiotrophoblasts

Which cells secrete HCG to prevent degeneration of the corpus luteum?

Syncytiotrophoblasts

Which trophoblast cells allow for continued progesterone supply?

Syncytiotrophoblasts

In which stages of placental development are syncytiotrophoblasts easily seen?

Both early/immature and term/mature placenta

Which cells lining the chorionic villi are located on the inner layer?

Cytotrophoblasts

Which cells produce anti-inflammatory cytokines in the placenta?

Cytotrophoblasts

Which cells help with implantation of the embryo into the uterus?

Cytotrophoblasts

Which trophoblast cells are short-lived and more numerous in the early/immature placenta?

Cytotrophoblasts

Which placental stage shows both syncytiotrophoblasts and cytotrophoblasts clearly?

Early/Immature Placenta

Which additional structures are visible in the early/immature placenta besides trophoblasts?

Intermediate trophoblasts and mesenchyme

In which placental stage are cytotrophoblasts short-lived and not easily visible?

Term/Mature Placenta

What structure do syncytiotrophoblasts form in the term/mature placenta?

Syncytial knots

What feature distinguishes a term/mature placenta from an immature one?

Presence of vasculature

How many trophoblast layers are visible in the early/immature placenta?

Two layers: inner cytotrophoblast and outer syncytiotrophoblast

How many trophoblast layers are visible in the term/mature placenta?

One layer: syncytiotrophoblast only

What happens to the cytotrophoblasts in the term/mature placenta?

They become inconspicuous

What type of mesenchymal connective tissue is found in the early/immature placenta?

Avascular mesenchymal connective tissue

What type of mesenchymal connective tissue is found in the term/mature placenta?

Vascular mesenchymal connective tissue

What are chorionic villi made up of?

Mesenchymal cells bordered by trophoblastic cells

What does the trophoblast differentiate into during implantation?

Cytotrophoblast and syncytiotrophoblast

Which trophoblastic cells are mitotically active?

Cytotrophoblast

Where are cytotrophoblasts located in relation to syncytiotrophoblasts?

Inner to the syncytiotrophoblast

What is the relative size of cytotrophoblasts?

Bigger cells

Are cytotrophoblasts present in the mature placenta?

No, they are short-lived

Non-mitotic mass of multinucleated cytoplasm - syncytiotrophoblasts

Where are syncytiotrophoblasts located?

At the outer periphery

What is the shape of syncytiotrophoblast cells?

Flattened

Are syncytiotrophoblasts present in the mature placenta?

Yes, they are long-lived