Chapter 56 - The Placenta

A

The fetal membranes are comprised of all of the following except the:

A) blastocyst

B) amnion

C) chorion

D) yolk sac

A

The chorionic plate is related to which one of the following?

A) fetal surface of the placenta

B) cotyledons and intervillous spaces

C) allantois of the yolk sac

D) maternal surface of the fetus

C

The decidual reaction that changes in the endometrium opposite the site of implantation is which one of the following?

A) decidua capsularis

B) decidue basalis

C) decidua vera

D) decidua frondosum

D

The major functioning unit(s) of the placenta is(are) which of the following?

A) cotyledons

B) yolk sac

C) amnion

D) chorionic villi

C

The placenta performs all of the following functions except:

A) protection

B) respiration

C) absorption

D) nutrition

A

The velementous placenta refers to a(n):

A) membranous insertion of the cord

B) insertion of the umbilical cord near the edge of the placenta

C) insertion of the umbilical cord at the margin of the placenta

D) arteriovenous anastomosis of the vessels within the placenta

A

By 9 weeks, the yolk sac should measure _____ millimeters (mm) in diameter:

A) less than 5

B) greater than 2

C) less than 2

D) greater than 5

B

Fusion of the amnion and chorion usually occurs by _______ weeks' gestation.

A) 20

B) 16

C) 12

D) 14

D

The function of the human chorionic gonadotropin (hCG) is to perform which one of the following?

A) develop Wharton's jelly around the cord

B) produce amniotic fluid

C) stimulate the yolk sac development

D) maintain the corpus luteum in early pregnancy

B

A marginal or an eccentric insertion of the umbilical cord into the placenta is which one of the following?

A) placenta previa

B) battledore placenta

C) vasa previa

D) velamentous placenta

A

The primary cause of placentomegaly is which one of the following abnormalities?

A) maternal diabetes

B) intrauterine infection

C) battledore placenta

D) intrauterine growth restriction (IUGR)

D

The most common site of fibrin deposition is which one of the following?

A) along the retroplacental area

B) within the hydatidiform mole

C) within the chorioangioma

D) along the subchorionic area

B

Complications of placenta previa include all of the following except:

A) postpartum hemorrhage

B) succenturiate placenta

C) maternal hemorrhage

D) premature delivery

B

Severe blood loss may occur with placenta ______.

A) increta

B) percreta

C) excreta

D) accreta

B

The presence of one or more accessory lobes connected to the body of the placenta by blood vessels is a ______ placenta.

A) circummarginate

B) succenturiate

C) circumvallate

D) battledore

C

Which one of the following statements about placental abruption is false?

A) bleeding in the decidua basalis occurs with separation

B) preterm labor may result

C) the bleed may lead to chorioangioma

D) placental abruption may be retroplacental or marginal abruption

C

An example of low-pressure bleed is which one of the following?

A) decompression of the uterus

B) trauma to the uterus

C) marginal abruption

D) retroplacental abruption

C

The maternal side of the placenta is decidua _______.

A) parietalis

B) capsularis

C) basalis

D) frondosum

C

The chorion around the gestational sac on the opposite side of implantation is chorion _______.

A) frondosum

B) vera

C) laeve

D) capsularis

C

A marginal placenta previa demonstrates which one of the following?

A) the edge of the placenta is near the internal cervical os

B) the placenta partially covers the internal cervical os

C) the placenta touches but does not cross the internal cervical os

D) the placenta is in the right lateral position

A

Which one of the following abnormalities might demonstrate a small placenta?

A) aneuploidy

B) maternal anemia

C) Rh sensitivity

D) maternal diabetes

C

Which one of the following occurs when the intramembranous vessels course across the internal cervical os?

A) battledore placenta

B) velamentous placenta

C) vasa previa

D) placenta previa

C

The growth of the chorionic villi superficially into the myometrium describes which one of the following?

A) placenta increta

B) succenturiate placenta

C) placenta accreta

D) placental migration

D

The attachment of the placental membranes to the fetal surface of the placenta describes which one of the following?

A) battledore placenta

B) succenturiate placenta

C) placenta accreta

D) circummarginate placenta

D

A circumscribed complex mass protruding from the fetal surface of the placenta is demonstrated on ultrasound. This appearance most likely represents which one of the following?

A) abruption placenta

B) circumvallate placenta

C) succenturiate placenta

D) chorioangioma

B

Which one of the following occurs when the cord inserts into the membranes before it enters the placenta?

a. battledore placenta

b. velamentous insertion

c. prolapse

d. vasa previa

B

All of the following are associated with increased risk for vasa previa, except:

a. low-lying placenta

b. placenta percreta

c. velamentous cord insertion

d. succenturiate placenta

C

the abnormal penetration of the uterine wall and other structures by the placenta is termed:

a. placenta accreta

b. placenta increta

c. placenta percreta

d. placental migration

A

a retroplacental abruption may not result in vaginal bleeding.

a. true

b. false

B

Placentomegaly is diagnosed when the placental thickness measures over ______ cm.

a. 3

b. 4

c. 5

d. 6

oxygenated, deoxygenated

the major role of the placenta is to permit the exchange of ___________ maternal blood with ______________ fetal blood

posterior, umbilical cord

Maternal vessels course _________ to the placenta and circulate blood into the placenta, whereas blood from the fetus reaches this point through the ________

chorionic plate

The fetal surface of the placenta, which is contiguous with the surrounding chorion, is termed the ________

basal plate

the maternal portion of the placenta that lies contiguous with the decidua basalis is termed the

chorionic villus

the major functioning unit of the placenta is the _______________

protection, nutrition, respiration, excretion

Before birth, the fetal membranes and the placenta perform the following functions and activities: (4 things)

spiral

Oxygenated maternal blood is brought to the placenta through 80-100 end branches of the arteries--the ______arteries

hypotension, renal, placental

the maternal placental circulation may be reduced by a variety of conditions that decrease uterine blood flow, such as severe _____________, ______________ disease, or _____________ infarction.

metabolism, endocrine, transfer

list the three main functions of the placenta

center

The attachment of the cord is usually near the _____ of the placenta

blood

Most of the amniotic fluid comes from the maternal _______ by diffusion across the amnion from the decidua parietalis and intervillous spaces of the placenta.

excrete, swallows

in the first trimester, the fetus begins to ____________ urine into the sac to fill the amniotic cavity; the fetus ______________ this fluid, and the cycle continues throughout pregnancy

subplacental

the placenta is separated from the myometrium by a _____________ venous complex

45-50mm

Although the placenta increases in size and volume with gestational age, the maximum thickness does not exceed _____.

position

the sonographer should always describe the ____________ of the placenta

full bladder

For the sonographer to visualize the internal os of the cervix, the patient should have a _________

succenturiate

when the sonographer sees two separate parts of the placenta that do not appear to communicate, a _____________ placenta should be considered

high, low

Before 20 weeks, uterine artery Doppler typically shows a _____ flow, _____ resistance pattern, particularly for the uterine artery on the same side as the placenta

placentomegaly

maternal diabetes and Rh incompatibility are primary causes for

previa

Placenta _______ is the implantation of the placenta in the lower uterine segment in advance of the fetus

complete

With ______ previa, the cervical internal os is completely covered by placental tissue

transperineal, translabial

other approaches that are useful in evaluating the lower uterine segment with ultrasound when the definition of the placenta needs to be clarified include ___________ and ______________

vasa

a potentially life threatening fetal complication of the placenta that occurs when large fetal vessels run in the fetal membranes across the cervical os is ___________ previa, which places them at risk of rupture and hemorrhage

placenta

abnormal adherence of part or all of the placenta with partial or complete absence of the decidua basalis is ____________ accreta

c section

the risk if placenta accreta increases in patients with placenta previa and uterine scar from previous ________

increta

Placenta ______ results from underdeveloped decidualization of the endometrium.

circumvallate

the attachment of the placental membranes to the fetal surface of the placenta rather than to the placental margin is a ______ placenta

abruption

The separation of a normally implanted placenta before term delivery is referred to as placental _______

retroplacental

____________ abruption results from the rupture of spiral arteries and is a "high pressure" bleed

marginal

________________ abruption results from tears of the marginal veins and respresents a "low pressure" blees

infarction

A focal discrete lesion caused by ischemic necrosis is placental _______.

gestational trophoblastic

in ______________ disease, the sonogram shows a uterine size larger than dates, no identifiable parts, and an inhomogeneous texture with variously sized cystic structures of the placenta that represent multiple vesicular changes throughout the placenta

chorioangioma

the second most common tumor of the placenta is known as