Lecture 25 & 26 Flashcards Preview

BPM II-ER > Lecture 25 & 26 > Flashcards

Flashcards in Lecture 25 & 26 Deck (15):
1

Describe the formation of the placenta.

.

2

Describe the fetomaternal
junction.

decidua basalis: maternal component

chorion frondosum (villous chorion): fetal component

3

Describe the placental circulation.

- intervillous spaces filled with maternal blood from spiral arteries
- tertiary villi float in the intervillous space
- gas exchange between maternal blood and fetal capillaries

4

Describe how the amniotic fluid is
produced and its circulation.

sources: amnion, maternal blood, fetal urine, skin, and secretions from respiratory tract

circulation: changes every 3 hours

5

Describe the development of allantois
and fetal membranes.

Allantois:
- diverticulum of yolk sac and extends into the body stalk
- obliterates and forms urachus

Amnion:
- forms as fluid filled membranous sac at 2nd week

Chorion:
- primary mesoderm fills space between trophoblastic wall and amnitic cavity adn the primary yolk sac

6

Discuss cleavage of the zygote and
formation of the blastocyst.

fertilization --> blastomere (2 cell) --> 4-cell --> 8 cell --> morula (12-16) --> early blastocyst --> later blastocyst

7

Describe early implantation of the
blastocyst.

- trophoblasts attach to endometrial lining at embryonic pole
- syncytiotrophoblast secrete proteloytic enzymes to erode endometrial lining allowing blastocyst to burrow into endometrial CT

8

Define the term “ectopic pregnancy”
and list the sites of occurrence and the most common site

Anywhere other than endometrium of uterus

most common: ampulla
others: ovaries, abdomen

9

Describe placenta
accreta, percreta
and previa and their clinical significance

placenta accreta: beyond decidua basalis
placenta percreta: through the layers of the uterus
placenta previa: at internal os

10

Describe hydatiform
mole and its association with choriocarcinoma

no or little embryonic tissue present; trophoblast develops, hCG produced, may give rise to choriocarcinoma

11

Describe the cause of hemolytic disease in a newborn(erythroblastosis
fetalis)

Rh+ baby and Rh- mommy; Ab attack baby

12

Describe embryogenesis of
monozygotic, dizygotic twins and conjoined twins

monozygotic:
- single zygote; identical
- 2 amniotic sacs
- 1 chorionic sac
- 1 placenta

Dizygotic:
- two zygotes
- 2 amnions & 2 chorions
- placentas may fuse

Conjoined:
- incomplete division of embryonic disc

13

Describe the mechanism of
twin to twin transfusion

preferential shunting of arterial blood in one twin to venous blood in the other.
- donor twin: small and anemic
- recipient twin: large and polycythemic

14

Describe the significance of
alpha fetoprotein assay

increased AFP = neural tube defects, anencephaly, and spina bifida

decreased AFP: trisomy 21

15

Describe the procedures for assessing fetal status including diagnostic amniocentensis, chorionic villus sampling, percutaneous umbilical cord blood sampling, alpha feto protein assay and fetal monitoring.

amniocentensis: retrieving amniotic fluid

chorionic villus sampling: as early as 7 weeks; detects chromosomal abnormalities

percutaneous umbilical cord: blood sample from umbilical vein