Embryology Exam 2: Placenta

Front 1

What is the Greek translation of "placenta"?

Back 1

"plakuos" which means flat cake

Front 2

What is placenta named after?

Back 2

its appearance

Front 3

What is placenta?

Back 3

a materno-fetal organ, which begins developing at implantation of the blastocyst and is delivered with the fetus at birth

Front 4

When does placenta begin developing?

Back 4

at implantation of the blastocyst

Front 5

When is placenta delivered?

Back 5

with the fetus at birth

Front 6

T/F. Placenta is the most well studied embryoninc structure.

Back 6

False; we have only begun to understand the man different functions of placenta, in addition to its role in embryonic nutrition

Front 7

What has been a recent novel discovery about placenta and placental blood?

Back 7

It has recently been seen as a new source for stem cells in bone marrow replacement therapy in many diseases

Front 8

Describe the process of placenta formation.

Back 8

1) the blastocyst implants, and the uterine endometrium responds by the decidual reaction
2) later the embryo bulges into the uterine cavity
3) the embryo is underlain by a zone of decidua called the decidua basalis
4) this will form the mature placenta.

Front 9

What is the dedidua basalis?

Back 9

it underlies the embryo, and forms the mature placenta

Front 10

Name a few characteristics of placenta at birth.

Back 10

1) embryonic/maternal organ
2) villous chorion/decidua basalis
3) continuous with amniotic and chorionic sacks

Front 11

T/F. At birth the embryonic surface alone is delivered.

Back 11

False; the embryonic surface AND the maternal surface are delivered at parturition (childbirth)

Front 12

Retention of the maternal and embryonic surfaces at birth may cause what?

Back 12

uterine hemorrhage

Front 13

At birth what are the dimensions of placenta?

Back 13

discoid up to 20 cm in diameter, 3 cm thick, and weight of 500-600 g.

Front 14

What shapes are present in placenta?

Back 14

1) accessory placenta,
2) bidiscoid,
3) diffuse
4) horseshoe

Front 15

What forms the cobblestone appearance on the maternal surface?

Back 15

cotyledons

Front 16

What is originally placental septa formed grooves?

Back 16

cotyledons

Front 17

What covers the maternal surface?

Back 17

maternal decidua basalis

Front 18

compare and contrast the maternal surface and the fetal surface.

Back 18

fetal:
maternal:

Front 19

What covers the fetal surface?

Back 19

amniotic membrane; attached to chorionic plate

Front 20

Where do umbilical vessels attach to?

Back 20

chorionic vessels which anastomose

Front 21

describe the umbilical cord attachment

Back 21

1-2 cm diameter, 30-90 cm long

Front 22

What is the basis of placental classification?

Back 22

1)histological (microscopic) structural organization
2) layers between fetal and maternal circulation

Front 23

What are the three main placental classifications? Which is for humans?

Back 23

1) haemochorial, endotheliochorial, and epitheliochorial
2) haemochorial-placenta where the chorion comes ind direct contact with maternal blood

Front 24

What is the placental type in humans?

Back 24

discoid; this type also includes mice, insectivores, rabbits, rats, and monkeys

Front 25

What determines the placenta shape?

Back 25

the persistent area of chorionic villi

Front 26

What is the placenta shape in humans? How does this occur?

Back 26

1) discoid
2) the circular area of the chorionic villi gives it its shape

Front 27

Which 4 layers separate maternal and fetal blood?

Back 27

1) syncitiotophoblast
2) cytotrophoblast
3) villi CT
4) fetal capillary epithelium

Front 28

What are the 3 main functions of placenta?

Back 28

1) metabolism
-synthesizes glycogen, cholesterol, and fatty acids
-provides nutrient and energy
2) transport
-gases/nutrition
-oxygen/CO2/CO
3) endocrine
-

Front 29

What is the major source of placental hormones?

Back 29

trophoblast cells

Front 30

What is the process of endometrial stromal cells (fibroblast-like) change in morphology (polygonal cells) and protein expression and secretion

Back 30

decidualization

Front 31

What placental abnormality occurs when there's abnormal adherence with absence of decidua basalis?

Back 31

placenta accreta

Front 32

What placental abnormality occurs when the placenta attaches deep into the uterine wall and penetrates into the uterine muscle (but not the uterine serosa)?

Back 32

placenta increta

Front 33

What percentage of placental abnormalities are accounted for by placenta increta?

Back 33

15-17%

Front 34

What occurrence during pregnancy significantly increases the incidence rate for placenta accreta?

Back 34

women with previous C-section, compared to those without a prior surgical delivery

Front 35

What placental abnormality occurs when placental villi penetrate the myometrium and through to uterine serosa?

Back 35

placenta percreta

Front 36

List and describe one placental abnormality.

Back 36

Use previous information to answer.
Options placenta accreta, placenta increta, placenta percreta.

Front 37

T/F. There are more placental cord abnormalities than placental abnormalities.

Back 37

False; there are very few abnormalities associated with umbilical cord development.

Front 38

What are abnormalities that most often occur during placental cord development?

Back 38

the cord can be abnormally long or short
-in most cases, such abnormalities do not cause extreme difficulties

Front 39

When do placental cord abnormalities cause difficulty in pregnancy?

Back 39

When long cords wrap around limbs or fetus neck
-this can restrict blood flow or lead to tissue/nerve damage

Front 40

cord torsion v. cord knotting

Back 40

1) cord knotting-occurs in 1%of cases; most of the time, has no effect; sometimes severe knotting prevents delivery of placental blood
2) cord torsion-also rare, can affect placental blood flow without knotting; sometimes fatal

Front 41

What is a placental infection?

Back 41

this is when several infective agents may cross into the placenta from the maternal circulation

Front 42

T/F. Placental infection is always fatal.

Back 42

False; there are a variety of bacterial infections that can occur, and they have a variety of potential outcomes

Front 43

T/F. Pregnant women have normal susceptibility to malaria.

Back 43

False; increased susceptibility

Front 44

What are the effects of malaria on the infant?

Back 44

sequestration of the infected RBCs cause low birth weight and other possible defects

Front 45

What are the four types of malaria cause by plasmodium falciparum?

Back 45

1) plasmodium falciparum (main)
2) p. vivax
3) p. ovale
4) p. malariae

Front 46

Where is malaria common?

Back 46

in regions where malaria is endemic, and with women in their first pregnancy (primigravida)

Front 47

T/F. HIV can sometimes cross the placenta from an infected mother to infect an unborn child.

Back 47

True.

Front 48

When is HIV most commonly transmitted to a child?

Back 48

breastfeeding, or during birth

Front 49

How can numbers be significantly reduced for HIV transmission from mother to child?

Back 49

if the mother is treated with antiretroviral drugs prior to delivery

Front 50

List all important processes in placental transport

Back 50

1. gases and nutrition
2. oxygen, carbon dioxide, carbon monoxide
3. water, glucose, vitamins
4. hormones, mainly steroid not protein
5. electrolytes
6. maternal antibodies
7. waste products-urea, uric acid, bilirubin
8. drugs and their metabolites (fetal drug addiction)
9. infectious agents (cytomegalovirus, rubella, measles, microorganisms)

Front 51

What hormone supports the corpus luteum, leutenizing hormone?

Back 51

human chorionic gonadotrophin (hCG)

Front 52

Describe two steroid hormones involved in placental endocrine system.

Back 52

1) progestins-progesterone, support endometrium and suppress uterine smooth muscle contractility
2) estrogens-estriol, stimulate growth of the myometrium and mammary gland development
*Both hormones support maternal endometrium

Front 53

T/F. Only progestins support maternal endometrium.

Back 53

False; both progestins and estrogens support maternal endometrium.

Front 54

What hormone probably plays a role in development of the uterus/placenta in the birth process?

Back 54

relaxin

Front 55

Which hormone has high levels in early pregnancy, and promotes angiogenesis?

Back 55

Relaxin

Front 56

Which hormone has high levels in early pregnancy, and promotes angiogenesis?

Back 56

Relaxin

Front 57

Which hormone has high levels in early pregnancy, and promotes angiogenesis?

Back 57

Relaxin

Front 58

____ ______ is characterized by the formation of large arterio-venous shunts that persist in the immediate post-partum period.

Back 58

Normal pregnancy

Front 59

____ ______ is characterized by the formation of large arterio-venous shunts that persist in the immediate post-partum period.

Back 59

Normal pregnancy

Front 60

____ ______ is characterized by the formation of large arterio-venous shunts that persist in the immediate post-partum period.

Back 60

Normal pregnancy

Front 61

What complication in pregnancy is characterized by minimal arterio-venous shunts, and thus narrower uterine arteries?

Back 61

Severe preclampsia

Front 62

What complication in pregnancy is characterized by minimal arterio-venous shunts, and thus narrower uterine arteries?

Back 62

Severe preclampsia

Front 63

What complication in pregnancy is characterized by minimal arterio-venous shunts, and thus narrower uterine arteries?

Back 63

Severe preclampsia

Front 64

In normal pregnancy, what happens to the cytotrophoblast?

Back 64

Extravillous cytotrophoblast extends beyond the decidua into the inner myometrium resulting the formation of funnels at the discharging tips of the spiral arteries.

Front 65

In normal pregnancy, what happens to the cytotrophoblast?

Back 65

Extravillous cytotrophoblast extends beyond the decidua into the inner myometrium resulting the formation of funnels at the discharging tips of the spiral arteries.

Front 66

In normal pregnancy, what happens to the cytotrophoblast?

Back 66

Extravillous cytotrophoblast extends beyond the decidua into the inner myometrium resulting the formation of funnels at the discharging tips of the spiral arteries.

Front 67

What are the two types of fibrinoid?

Back 67

1) fibrin-type fibrinod: a maternal blood-clot product
2) Matrix-type fibrinoid: secreted by invasive extravillous trophoblast cells

Front 68

What are the two types of fibrinoid?

Back 68

1) fibrin-type fibrinod: a maternal blood-clot product
2) Matrix-type fibrinoid: secreted by invasive extravillous trophoblast cells

Front 69

What are the two types of fibrinoid?

Back 69

1) fibrin-type fibrinod: a maternal blood-clot product
2) Matrix-type fibrinoid: secreted by invasive extravillous trophoblast cells

Front 70

Which layer is thought to act to prevent excessively deep implantation?

Back 70

Fibrinoid layer (Nitabuch's layer)

Front 71

Which layer is thought to act to prevent excessively deep implantation?

Back 71

Fibrinoid layer (Nitabuch's layer)

Front 72

Which layer is thought to act to prevent excessively deep implantation?

Back 72

Fibrinoid layer (Nitabuch's layer)

Front 73

Which layer is thought to act to prevent excessively deep implantation?

Back 73

Fibrinoid layer (Nitabuch's layer)

Front 74

Which layer is thought to act to prevent excessively deep implantation?

Back 74

Fibrinoid layer (Nitabuch's layer)

Front 75

Which layer is thought to act to prevent excessively deep implantation?

Back 75

Fibrinoid layer (Nitabuch's layer)

Front 76

Which layer is thought to act to prevent excessively deep implantation?

Back 76

Fibrinoid layer (Nitabuch's layer)