Chapter 21: Normal Placenta and Umbilical Cord

Question 1

extraplacental lobe smaller than the placenta

Answer 1

succenturiate lobe

Question 2

uterine contractions that do not lead to labor

Answer 2

Braxton-Hicks

Question 3

Lobule or subdivision of the maternal placenta containing fetal vessels, chorionic villi, and the intervillous space

Answer 3

Cotyledons

Question 4

the functional layer of the endometrium in the gravid woman

Answer 4

decidua

Question 5

area between the myometrium and placenta

Answer 5

retroplacental

Question 6

mucous tissue surrounding the umbilical cord

Answer 6

Wharton jelly

Question 7

Grade 0 placenta

Answer 7

no calcifications (to about 31 weeks)

Question 8

Grade 1 placenta

Answer 8

scattered calcifications (31-36 weeks)

Question 9

Grade II placenta

Answer 9

Basal calcifications with increase in lobulations (36-38 weeks)

Question 10

Grade III placenta

Answer 10

basal and interlobar septal calcifications (38 weeks to term)

Question 11

Most term pregnancies have grade __ or ___ placenta

Answer 11

I or II

Question 12

connects fetus and placenta

Answer 12

umbilical cord

Question 13

3 vessels of umbilical cord

Answer 13

2 arteries and 1 vein

Question 14

_____ carry deoxygenated blood from the fetus to the placenta

Answer 14

arteries

Question 15

____ brings oxygenated blood from the fetus to the placenta

Answer 15

vein

Question 16

Placental evaluation consists of assessment of:

Answer 16

size
shape
consistency
location

Question 17

Umbilical cord evaluation consists of assessment of:

Answer 17

confirming number of vessels
documenting length
appearance of cord
visualizing portions of insertion

Question 18

The umbilical cord originates from the fusion of ____ and ____.

Answer 18

yolk sac stalk and omphalomesenteric duct

Question 19

The umbilical cord can be seen around __ weeks gestation

Answer 19

7

Question 20

outpouching from urinary bladder

Answer 20

urachus

Question 21

The urachus forms the _____

Answer 21

allantois

Question 22

Average length of umbilical cord at term

Answer 22

51.5-61 cm

Question 23

Mean circumference of umbilical cord at term

Answer 23

3.8 cm

Question 24

______ refers to visualization of several portions of cord folded onto each other

Answer 24

“stack of coins”

Question 25

Maternal portion of the placenta arises from:

Answer 25

endometrium

Question 26

Fetal portion of the placenta arises from:

Answer 26

section of chorionic sac

Question 27

functional layer of endometrium

Answer 27

decidua

Question 28

lies deep to conceptus; develops into the maternal side of the placenta

Answer 28

decidua basalis

Question 29

overlies conceptus

Answer 29

decidua capsularis

Question 30

encompasses all of remaining decidua

Answer 30

decidua parietalis/vera

Question 31

arise from implanting conceptus

Answer 31

trophoblasts

Question 32

Placental functions for fetus

Answer 32

nutritional respiratory excretory metabolic

Question 33

The placenta weight about ___ to ____ grams at term

Answer 33

480-600

Question 34

fused layer of amnion and chorion (chorionic plate)

Answer 34

fetal side of placenta

Question 35

20 functional lobes or cotyledons; composed of maternal sinusoids and chorionic villous structures

Answer 35

maternal side of placenta

Question 36

The placenta is relatively _____.

Answer 36

homogeneous

Question 37

cord insertion into central portion of placenta

Answer 37

normal

Question 38

Cord insertion eccentrically near margins

Answer 38

Battledore placenta

Question 39

Cord insertion below edge of placenta

Answer 39

velamentous insertion

Question 40

Placental thickness greater than ____ prior to 24 weeks is considered abnormal

Answer 40

4 cm

Question 41

pumped through spiral arteries within decidua basalis, enters intervillous spaces surrounding and bathing villi, gases and nutrients exchange across walls of villi

Answer 41

maternal blood

Question 42

carried to placenta by umbilical arteries, circulates through capillaries in chorionic villi within placental lobes, resulting in oxygenated blood within venous capillaries

Answer 42

deoxygenated fetal blood

Question 43

_____ Doppler should only be used when study clinically indicates.

Answer 43

Pulsed-wave

Question 44

The normal cervical length is between __ and __ cm

Answer 44

3 5

Question 45

Sonographer should see placenta transabdominally by ____ weeks.

Answer 45

8-10

Question 46

Chorionic plate can be seen transabdominally approximately ___ weeks

Answer 46

12

Question 47

Umbilical artery waveform

Answer 47

low-resistance high diastolic

Question 48

Intraplacental texture early pregnancy

Answer 48

echogenic focal thickening of wall of gestational sac

Question 49

intraplacental texture end of first trimester

Answer 49

fine, granular homogeneous texture

Question 50

intraplacental texture second and third trimesters

Answer 50

intraplacental and subchorionic vascular spaces may be seen

Question 51

intraplacental texture late third trimester

Answer 51

cystic areas located centrally within clearly delineated lobes; nonvascular areas represent necrosis

Question 52

composed of decidua basalis and portions of myometrium

Answer 52

Retroplacental complex

Question 53

The retroplacental complex can be identified as early as __ weeks

Answer 53

14

Question 54

Factors that affect placental grading

Answer 54

smoking low maternal age parity season of the year

Question 55

When imaging the placenta, cord, or cervix, use an angle of incidence as close to ___ degrees as possible to ensure optimal image detail and measurements

Answer 55

90

Question 56

Nutrient exchange between the fetus and the mother occurs within the ____ of the placenta.

Answer 56

villi

Question 57

The retroplacental complex is _____.

Answer 57

hypoechoic

Question 58

A centrally located cord insertion into the placental is considered ____

Answer 58

normal

Question 59

The placenta is responsible for all but: a. hormonal functions b. nutritive functions c. respiratory functions d. excretory functions

Answer 59

a

Question 60

Vascular resistance changes in the umbilical cord can be caused by all except: a. umbilical cord compression b. maternal hypotension c. placental tumor d. maternal diabetes

Answer 60

b

Question 61

The umbilical cord originates from fusion of the yolk sac stalk and the omphalomesenteric duct at approximately:

Answer 61

7 weeks gestation

Question 62

The maternal side of the placenta: a. is homogeneous b. is made of approximately 20 cotyledons c. is bordered by amnion d. attaches to the chorionic plate

Answer 62

b

Question 63

The umbilical cord consists of:

Answer 63

two arteries, a vein, and Wharton jelly

Question 64

The normal at term umbilical cord length is approximately:

Answer 64

52-61 cm

Question 65

The normal term placenta weighs between:

Answer 65

480-600 grams

Question 66

A normal placental thickness at 24 weeks gestation is less than:

Answer 66

4 cm

Question 67

Placental calcifcation may be caused by all except: a. lung maturity b. maternal smoking c. parity d. season of the year

Answer 67

a

Question 68

A normal mean circumference of the term umbilical cord is:

Answer 68

3.8 cm

Question 69

More than ____ of placentas show macroscopic calcification after ____ weeks.

Answer 69

50% 33

Question 70

_______ carry deoxygenated blood from the fetus to the placenta. The ____ returns blood back to the fetus from the placenta.

Answer 70

Umbilical arteries umbilical vein

Question 71

The umbilical _____ are longer than the _____ and wind around it.

Answer 71

arteries vein

Question 72

The use of ______ should make visualization of the umbilical cord insertion into the placenta easily identifiable.

Answer 72

Color Doppler

Question 73

An eccentric cord insertion (near the margin) to the placenta is called _______.

Answer 73

battledore placenta

Question 74

Maternal disease can affect the size, vascularization, and _____ of the placenta.

Answer 74

function

Question 75

The vascular channels within the placenta are part of a ___-impedance system.

Answer 75

low

Question 76

A _____ MHz transducer is adequate for most routine imaging of the placenta

Answer 76

3-3.5

Question 77

A(n) _______ bladder can cause a false positive appearance of placenta previa.

Answer 77

overdistended

Question 78

When scanning the placenta, the beam should be _______ to the chorionic plate, especially when measuring thickness.

Answer 78

perpendicular

Question 79

An accessory placental lobe is also known as a _____ lobe.

Answer 79

succenturiate

Question 80

Placental texture changes from an _____ focal thickening of the wall of the gestational sac early in pregnancy to the fine, granular, ______ texture seen from the end of the first trimester.

Answer 80

echogenic homogeneous

Question 81

The umbilical artery has a ___-resistance, ____ diastolic blood flow characteristic in the normal placenta.

Answer 81

low high

Question 82

A late third trimester placenta may exhibit cystic areas located centrally within clearly delineated lobes which may represent areas of _____.

Answer 82

necrosis

Question 83

The nutrient exchange between the fetus and the mother occurs within the ______ in the placenta.

Answer 83

intervillous sinue