Placenta

Question 1

What does the syncytiotrophoblast give rise to?

Answer 1

the fetal placenta that invades the endometrium.

Question 2

What gives rise to the syncytiotrophoblast?

Answer 2

the cytotrophoblast

Question 3

when do the fetal components come into contact with the maternal blood?

Answer 3

end of the second week of gestation

Question 4

where do the villi develop from ?

Answer 4

the syncytiotrophoblast and the wall of the chorion

Question 5

What do the villi hold?

Answer 5

all the fetal blood vessels

Question 6

where is maternal blood dumped for exchange with the fetal components?

Answer 6

into the intervillus space which are separated into segments called cotyledons each separated by CT septa

Question 7

What is the maternal component of the placenta called?

Answer 7

decidua basalis

Question 8

What barriers exists for diffusion of nutrients and O2 from maternal blood to fetal villi?

Answer 8

the syncytiotrophoblast and the cytotrophoblast which continue along the villi to the decidua basal is where they also lie.

Question 9

What blood vessels supply the intervillus space?

Answer 9

uterine spiral arteries

Question 10

What is the fetal portion of the placenta called?

Answer 10

the chorionic plate (amnion and chorion fused)

Question 11

How can you tell the chorionic plate from the decidua basalis?

Answer 11

the chorionic plate looks more of a solid lighte pink with some white above it. the decidua basalis is more cellular looking and scattered cells, darker pink (up close)

Question 12

What is the chorion frondosum?

Answer 12

region of the chorion from which the villi extend toward the decidua basalis

Question 13

What type of a villi exists in the basal plate?

Answer 13

an anchoring villus that embeds into the decidua basalis

Question 14

What are the 3 different cells of the basal plate (decidua basalis)?

Answer 14

decidual cells: stromal cells of the endometrium that enlarge and because lighter pink and frothy looking
cytotrophoblastic cells: darker pink
fibrinoid: formed from both cell types and is highly eosinophilic compared to the two cell types.

Question 15

When do the villi consist of only syncytiotrophoblast cells?

Answer 15

in the last trimester the cytotrophoblastic cells become incorporated into the syncytiotrophoblastic layer so that the syn is the only layer around in the villi in the last trimester

Question 16

When do the RBCs of the fetus become non-nucleated?

Answer 16

third trimester (24-36 weeks)

Question 17

What does hCG do?

Answer 17

placenta makes hCG which causes the corpus luteum to continue secreting estrogen and progesterone and maintain the uterine lining

Question 18

Is the mucosa of the cervix shed during mestruation?

Answer 18

NO!

Question 19

If the vagina doesn’t have glands, where do its secretions come from?

Answer 19

cervical glands in the dense CT of the cervix

Question 20

What is the epithelium of the vagina?

Answer 20

stratified squamous non-keritinized overlying CT with lots of elastic fibers and thin-walled blood vessels. NO GLANDS!