Chapter 55 Key terms

Question 1

the transformation once fertilization occurs through to the fetal stage

Answer 1

Embryogenesis

Question 2

cellular outermost extraembryonic membrane composed of trophoblast lined with mesoderm; it devfelopes villi about 2 weeks after fertilization, is vascularized by allantoic vessels a week later, gives rise to the placenta, and persists until birth

Answer 2

Chorion

Question 3

smooth membrane enclosing the fetus and amniotic fluid; it is loosely fused with the outer chorionic membrane except at the placental insertion of the umbilical cord, where the amnion is contiguous with the membranes surrounding the umbilical cord

Answer 3

Amnion

Question 4

circular structure within the gestational sac seen on ultrasound between 4-10 weeks of gestational age; supplies nutrition, facilitates waste removal and is the origin of early hematopoietic stem cells in the embryo; it lies between the chorion and the amnion

Answer 4

yolk sac

Question 5

the early beginnings of the umbilical cord that extend from the yolk sac through the yolk stalk

Answer 5

allantois

Question 6

the fetal surface of the placenta

Answer 6

Chorionic plate

Question 7

the decidual reaction that occurs between the blastocyte and the myometrium

Answer 7

Decidual basalis

Question 8

microscopic vascular projections from the chorion that combine with the maternal uterine tissue to form the placenta

Answer 8

intervilllus spaces, chorionic villus

Question 9

layer of the placenta that is filled with several mainstem villi and their branches

Answer 9

cotyledons

Question 10

oxygen exchange, metabolism, and endochrine function

Answer 10

functions and activities of the placenta

Question 11

maternal blood flows in through the endbranches of the uterine artery and spiral arteries, flows around the surface of the villi, Oxy rich blood flows to the fetus vis the Umb V and returns through the Umb A’s.

Answer 11

fetal-placental-uterine circulation

Question 12

Normal less than 600g and less than 4cm thick.

Answer 12

placental sizes

Question 13

normal connection is near center of placenta. Battledore is at the margin within 10mm of the edge and velamentous inserts on the membranes

Answer 13

cordal attachments

Question 14

ideal is fundal location, very important to note if it is near or over the CX

Answer 14

placental positions

Question 15

graded 1-4 based on sonographic appearance

Answer 15

maturity and grading

Question 16

placentomegaly, placenta previa, vasa previa,

Answer 16

abnormalities of the placenta

Question 17

on the margin or covering the CX

Answer 17

abnormal placental attachments

Question 18

presence of one or more accessory lobes connected to the body of the placenta by placenta vessels

Answer 18

Succenturiate Placenta

Question 19

condition where the chorionic plate is smaller than the basal plate, the margin is raised with a rolled edge

Answer 19

Circumvallate Placenta

Question 20

the chorionic placve of the placenta is smaller than the basal plate, with a flas interface between the fetal membrane and the placenta

Answer 20

Circummarginate Placenta

Question 21

bleeding from the placenta from any cause

Answer 21

Placental Hemorrhage

Question 22

separation of a normally implanted placenta prior to term delivery

Answer 22

Placental Abruption

Question 23

focal discrete lesion caused by ischemic nechrosis, found in 25% of pregnancies

Answer 23

Placental infarcts

Question 24

molar pregnancies, benign or malignant, include partial, complete and coexisitng

Answer 24

Placental Tumors