Lecture 11:Anatomy of the Placenta

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What is the primary function of the placenta?

Regulation of fetal movement

Production of breast milk

Nutrient and gas exchange between the fetus and the mother (correct)

Fetal heart rate regulation

What is the characteristic of the maternal surface of the placenta?

It is covered by a thin layer of decidua basalis (correct)

It is composed of chorionic vessels

It is attached to the umbilical cord

It is covered by a thick layer of decidua basalis

What is the function of the placenta in terms of hormone secretion?

Producing breast milk hormones

Regulating fetal heart rate

Only producing estrogenic hormones

Producing progesterone, estrogenic hormones, and human chorionic gonadotropin (correct)

What is the shape of the placenta at full term?

Disc-like Signup and view all the answers

What is the function of the villi in the placenta?

To facilitate gas exchange and metabolic transfer Signup and view all the answers

What happens to the placenta after birth?

It is expelled from the mother's body Signup and view all the answers

What is the primary function of cytotrophoblast cells in the development of the placenta?

To transform spiral arteries into low-resistance vessels Signup and view all the answers

What is the characteristic of the vessels formed after the invasion of spiral arteries by cytotrophoblast cells?

Larger-diameter, low-resistance vessels Signup and view all the answers

What is the term for the villus when mesodermal cells penetrate the core of the primary villi and grow towards the decidua?

Secondary villus Signup and view all the answers

What is the function of the villous capillary system formed by the end of the third week?

To supply the embryo with nutrients and oxygen Signup and view all the answers

What is the significance of the heart beginning to beat in the fourth week of development?

It allows the villous system to supply the embryo with essential nutrients and oxygen Signup and view all the answers

What is the term for the villus when mesodermal cells in the core of the villus begin to differentiate into blood cells and small blood vessels?

Tertiary villus Signup and view all the answers

What is the primary function of the free villi?

Exchanging nutrients and other factors between maternal and fetal circulations Signup and view all the answers

What is the term for the part of the endometrium where the placenta will form?

Decidual plate Signup and view all the answers

What is the process that occurs by the beginning of the fourth month?

Cytotrophoblastic cells disappear Signup and view all the answers

What is the term for the villi that extend from the chorionic plate to the decidua basalis?

Stem villi Signup and view all the answers

What is the result of the disappearance of cytotrophoblastic cells?

The only layers separating maternal and fetal circulations are the syncytium and endothelial wall Signup and view all the answers

By what day is the embryo attached to its trophoblastic shell by a narrow connecting stalk?

19th or 20th day Signup and view all the answers

What is the result of severe reductions of uteroplacental circulation?

Fetal hypoxia and intrauterine growth restriction Signup and view all the answers

How many layers does the placental membrane composing at full term?

Three layers Signup and view all the answers

What is the function of the arterio-capillary venous network in the branch chorionic villi?

It brings the fetal blood extremely close to the maternal blood Signup and view all the answers

What is the result of reductions of uteroplacental circulation?

Fetal hypoxia and intrauterine growth restriction Signup and view all the answers

What is the composition of the placental membrane up to 20 weeks?

Four layers Signup and view all the answers

What is formed at the umbilical cord?

One umbilical vein Signup and view all the answers

What type of cells cover the surface of the decidual septa?

Syncytial cells Signup and view all the answers

How many spiral endometrial arteries discharge into the intervillous space?

80-100 Signup and view all the answers

What is the purpose of the decidual septa in the placenta?

To divide the placenta into compartments Signup and view all the answers

What is the function of the umbilical arteries in the fetal placental circulation?

To carry poorly oxygenated blood from the fetus to the placenta Signup and view all the answers

What is the result of the pressure dissipation in the intervillous space?

The blood flows slowly around the branch villi Signup and view all the answers