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Flashcards in Placenta & Immunology Deck (67)
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1

The infant is dependent on the placenta for what functions?

Pulmonary, Hepatic, Renal

2

Maternal blood spurts from the __________ into the placental intervillous space and bathes the outer syncytiotrophoblasts

uteroplacental vessels

3

True or False: Fetal and maternal blood are not mixed in this hemochorial placenta

True

4

Where does the human placental formation begin?

Trophectoderm aka Morula

5

What is the invasive fxn of the trophoblast?

promotes implantation

6

What is the endocrine fxn of the trophoblast?

Endocrine function: maternal physiological adaptations, pregnancy maintenance

7

8th day after fertilization, what cells are formed on the outside. These are multinucleated

Syncitiotrophoblast

8

8th day after fertilization, what cells are formed on the inside. These are Germinal cells for syncytium and there is a well-demarcated cell border, single nucleus, undergoes DNA synthesis and mitosis

Cytotrophoblast

9

After implantation, trophoblasts differentiate further along two main pathways. What are these 2?

Villous Trophoblast & Exravillous Trophoblast

10

What is the function of Villous trophoblast?

It gives rise to CHORIONIC VILLI, which primarily transports oxgen, nutrients and other compounds bet mother and baby

11

The extravillous trophoblast is further differentiated into what? (2)?

Interstitial Trophoblast & Endovascular Trophoblast

12

Fxn of Interstitial Trophoblast

invade decidua and penetrate myometrium to form PLACENTAL BED GIANT CELLS. They also surround spiral arteries

13

Fxn of Endovascual Trophoblast

penetrate spiral artery LUMEN. Converts it from narrow-lumen, muscular spiral arteries into DILATED, LOW-RESISTANCE UTEROPLACENTAL VESSELS

14

by the 10th day... Blastocyst becomes totally encased within the _________

Endometrium.
Embryo enlarges -> more maternal decidua basalis is invaded by syncytiotrophoblast

15

by the 12th day... syncitiotrophoblast is permeated by a system of intercommunicatiing channels called ______

Trophoblastic Lacunae
It is filled with Maternal Blood

16

What does the extravillous cytotrophoblast give rise to?

Solid Primary Villi = Cytotrophoblast (Langhan's Cell) Core + Syncitiotrophoblast Cover

17

Trophoblast-lined labyrinthine channels form....

Intervillous space

18

the solid cellular columns form the...

Primary Villous Stalks

19

At 8-10 weeks, this is formed via fusion of amnionic and primary chorionic plate mesenchyme

chorionic plate formed

20

Once angiogenesis begins in the mesenchymal cores, what are formed?

Tertiary Villi

21

At what day does the maternal blood enter the intervillous space?

day 15

22

At the 17th day, fetal blood vessels are _____ & placental circulation is _________

Functional & established

23

What is the contact between the trophoblast & maternal blood

Hemochorial Placenta

24

Hemochorial Placenta can be subdivided into:

Hemodichorial and Hemomonochorial.

25

In early pregnancy,villi are distributed _______ of the chorionic membrane

over the entire PERIPHERY

26

What is the fetal component of the placenta?

Chorion Frondosum or Leafy Chorion

27

Which part of the chorion becomes the avascular fetal membrane that abuts the decidua parietalis?

Chorion Laeve or Smooth Chorion

28

This is composed of cytotrophoblasts and fetal mesodermal mesenchyme that survives in a relatively low-oxygen atmosphere

Smooth Chorion

29

During first half of pregnancy, these accumulate in the decidua and are found in direct contact w/ trophoblasts. They lack cytotoxic fxns and are able to dampen inflammatory TH17 cells

Decidual Natural Killer Cells

30

These cells play a regulatory role in inhibiting NK cell killing during pregnancy

Decidual Macrophages

31

These promote decidual invasion toward spiral arteries

IL-8 & interferon-inducible protein 10

32

When is the trophoblast highly invasive?

First trimester

33

Invasive trophoblasts secrete _______ that digest ECM and activate proteinases already present in the endometrium

Proteolytic enzymes

34

This appears to be critical for human trophoblst invasion

MMP-9

35

During this time, there is limited invasiveness of trophoblasts

Late Pregnancy

36

This promotes invasion into the endometrium

Insulin-like growth factor II

37

secreted by decidual cells which blocks the autocrine loop

Insulin-like factor binding protein type 4

38

Truncal/main stem villi = lobule/cotyledon

Functional Unit

39

The ff are functions of this type of cell found during placental maturation:
Phagocytic
Immunosuppressive
Produces cytokines
Regulates trophoblast function

Hofbauer cells

40

Which MHC/s are absent from villous trophoblasts?

I & II

41

Normal implantation depends on....

controlled trophoblastic invasion of maternal EM-decidua and spiral arteries

42

This regulate trophoblast invasion

Uterine Natural Killer Cells

43

Tough, pliable, tenacious membrane
Provides tensile strength of fetal membranes

Amnion

44

Amnion is first identified during...

7th or 8th day

45

the tensile strength of the amnion is due to....

Cross-linked interstitial collagens I (tensile strength) & III (+ tissue extensibility)

46

Until when does the amniotic fluid increase?

increases until 34 weeks, then declines

47

True or false:
As pregnancy advances:
Yolk sac becomesl larger
Pedicle grows shorter
Expanding amnion fuses with chorion laeve
Covers the placental disc and lateral surface of the body stalk  UMBILICAL CORD/FUNIS

FALSE
As pregnancy advances:
Yolk sac becomesl SMALLER
Pedicle grows LONGER
Expanding amnion fuses with chorion laeve
Covers the placental disc and lateral surface of the body stalk  UMBILICAL CORD/FUNIS

48

most common vascular anomaly in the absence of 1 artery

Meckel Diverticulum

49

2 routes of blood flow

Ductus venosus
Hepatic circulation

50

Umbilical arteries are obliterated and become....

Medial umbilical ligaments

51

This hormone is almost exclusively synthesized in the placenta. May be elevated in fetal kidney & malignant tumors

HCG

52

Peak of HCG

Complete molecule peaks at 8-10 weeks

53

Give the fxns of HCG

Rescue & maintenance of corpus luteum
Stimulation of fetal testicular testosterone secretion
Leydig cell replication: sexual differentiation
Stimulate maternal thyroid gland
Promotion of relaxin
Regulates expansion of uterine NK cells

54

low plasma HCG indicates...

Early pregnancy wastage (abortion), ectopic pregnancy

55

elevated plasma HCG indicates...

Multifetal pregnancy, erythroblastosis fetalis, GTD

56

Proportional to placental mass
Synthesis is stimulated by insulin and insulin-like growth factor-1
Inhibition is by PGE2 and PGF2a

Human Placental Lactogen

57

Actions of hPL

Promotes maternal lipolysis
Inhibits leptin secretion by term trophoblasts
Inc maternal β-cell proliferation
Potent angiogenic hormone

58

This persists after fetal demise

Placental Progesterone

59

principal precursor for placental estradiol synthesis

DHEA-S

60

most impt source of placental estrogen precursors

Fetal Adrenal Glands

61

source of 90% of placental estriol precursors

fetus

62

85-90% of progesterone and estrogen formed in

Syncitiotrophoblast

63

Fetal glands take up lipoproteins as a source of cholesterol.

(LDL>HDL>VLDL)

64

in Anencephaly there is high levels of

Fetal Adrenal Steroid Precursor

65

Used to assess level of serum estriol

maternal serum triple or quadruple screening test

66

what do you check in triple screen

alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), unconjugated estriol

67

what is added to the triple screen to be quad?

Inhibin A