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Flashcards in Exam II Qs Deck (131)
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1

An increase incidence of what condition is strongly associated with increase in maternal age?

Trisomy 21
Trisomy 18
Trisomy 13
Anencephaly
Ambiguous external genitalia

Trisomy 21

2

Cleft palate is a result in a defect in what developmental mechanism?

Failure to fuse
Failure to merge
Faulty inductive tissue interaction
Disturbance in tissue reabsorption
Absence of normal cell death

Failure to fuse

3

Which condition is related to maternal imprinting?

Accessory placental lobes
Placenta previa
Oligohydramnios
Single umbilical artery
Hydratidform mole

Hydratidform mole

4

Phocomelia is most likely to be seen after maternal exposure to which teratogenic agent during first trimester of pregnancy?

Alcohol
Aminopterin
Androgens
Ionizing radiation
Thalidomide

Thalidomide

5

The most serious threat of hydrop fetalis is CNS damage. The affected brain is enlarged and edematous, and when sectioned has a bright yellow color, particularly basal nuclei, thalamus, cerebellum, and cerebral gray matter, and spinal cord. The CNS damage is known as which of the following?
Erythroblastosis fetalis
Kernicterus
Phenylketonuria
Galactosemia

Kernicterus

6

What is the initial initiator of future forelimb development?
Hoxd
Tbx5
Shh
Gli3

Tbx5

7

A high concentration in amniotic fluid results in neural tube defects?
Lecithin
Alpha fetoprotein
Kernicterus
Creatinine

Alpha fetoprotein

8

The most serious threat of hydrop fetalis is CNS damage. The affected brain is enlarged and edematous, and when sectioned has a bright yellow color, particularly basal nuceli, thalamus, cerebellum, cerebral gray matter and spinal cord. The CNS damage is known as which of the following?

Erythroblastosis fetalis
Kernicterus
Phenylketonuria
Galactosemia

Kernicterus

9

The sclerotome arises from cells that were located in which of the following locations

Notocord
Paraxial mesoderm
Intermediate mesoderm
Lateral mesoderm

Paraxial mesoderm

10

The cardiogenic plate arises from where?

Embryonic endoderm
Somatic mesoderm
Splanchnic mesoderm
Intermediate mesoderm
Neural crest

Splanchnic mesoderm

11

An inductive stimulus from which structure stimulates the transformation of the epithelial sclerotome into secondary mesenchyme?

Neural crest
Somite
Ectodermal placodes
Embryonic endoderm
Notochord

Notochord

12

Intermediate mesoderm is the precursor of the:

Urogenital system
Heart
Somites
Body wall
Vertebral bodies

Urogenital system

13

Name the 4 stages in the development of the chorionic villi, state characteristics of each

1. Previllous embryo - no villi via trophoblast

2. Primary villous stage - solid, cytotrophoblastic, ectodermal primary villi appear

3. Secondary villous - mesodermal cores appear within primary villi

4. Tertiary villous stage - blood vessels within mesenchymal core of secondary villi

14

What tissue in the mature placenta directly interfaces with the maternal uterine connective tissue?

Cytotrophoblast cells
Syncytiotrophoblast cells
Trophoblast cells
Decidual cells
None of the above

Cytotrophoblast cells

15

Describe the location of the chorionic plate in the mature placenta

(mesoderm) faces away from the chorionic villi towards the chorionic cavity

16

Describe the location of the cytotrophoblast shells in the mature placenta, what are they formed by?

Formed by expansion of the cytotrophoblastic columns over the maternal decidual cells

17

List the 5 structures involved in the final development of the placenta

Cytotrophoblast
Cytotrophoblast columns
Cytotrophoblast shells
Anchoring villi
Chorionic plate

18

What are the anchoring villi of the mature placenta anchored to?

The cytotrophoblastic shell (as opposed to floating villi)

19

What maternal tissues are lost at childbirth? (3)

Decidua capsularis

Chorion laevae

Amnion

20

What is the fate of the decidua capsularis?

Undergoes atrophy

21

Distinguish between early vs. late placenta

Early:
Thick, low permeability, small SA, total diffusion conductance is miniscule

Late:
Thin, high permeability, large SA, large increase in placental diffusion

22

State the oxygen pressure gradient near the end of pregnancy of the mother and fetus

PO2 mother = 50mmHg

PO2 fetus = 30mmHg

23

How does adequate oxygenation occur with such a low pressure gradient near the end of pregnancy?

Fetal Hb has a greater affinity for O2
Fetal blood has more Hb than mother (50%)
Bohr effect

24

Define Bohr effect

Hb can carry more O2 at a low PCO2

Curve is shift left for fetal, right and down for maternal

25

Define the double Bohr effect

The double shift in the maternal blood and fetal blood

26

Where is hCG secreted from, when, and what is its function?

Via syncytial trophoblast cells into maternal fluids

Measurable at 8-9d after ovulation, max = 10-12w pregnancy

Prevents degradation of corpus luteum & give growth
Causes CL to secrete more progesterone & est
Exerts interstitial cell-stimulating effect on testes of male fetus = testosterone production

27

Where is estrogen secreted from, when, and what is its function?

Syncytiotrophoblast cells of placenta

Toward end of pregnancy, 30X more via androgenic steroid compounds (mom&fetal adrenal glands) Converted by trophoblast cells into estradiol, estrone, and estriol

Uterine, breast, external genitalia enlargement
Breast ductal growth
Relaxation of pelvic ligaments

28

Where is progesterone secreted from and what is its function?

Small quantities = corpus luteum
Large quantities = placenta

Causes decidual cells to develop in the endometrium
Decreases contractility of pregnant uterus
Increases secretions of fallopian tubes and uterus
May work w/ est to prepare breast for lactation

29

When is human chorionic somatomammotropin secreted and what is its function?

5th week

Decreased insulin sensitivity and decreased utilization of glucose by mother
General metabolic hormone

30

Define malformation

Primary errors of morphogenesis.

Usually multifactoral, involving a number of etiological agents like genetic and environmental factors