2-24-16-Fertilization, Implantation, Placental Development (Cole)

Question 1

What are 3 main events in fertilization?

Answer 1

• Acrosome rxn
• Sperm binding to ZP3
• Sperm-egg fusion

Question 2

During the acrosome rxn, the outer membrane of the sperm binds to the ___ receptor which allows for the acrosome rxn or the release of enzymes from the acrosomal space of the sperm to break down the ___

Answer 2

ZP3

Zona pellucida

Question 3

This process prevents polyspermy which is an egg to be fertilized by more than 1 sperm

Answer 3

Cortical rxn

Question 4

The immunoglobulin superfamily protein __ is required for sperm to fuse with eggs, as is the protein CD9 (egg)

Answer 4

Izumo

Question 5

A mutation in __ creates the inability for the sperm to fuse to the egg and undergo the acrosome rxn

Answer 5

Izumo

Question 6

The __ component in the cortical rxn is a change in resting potential of the oocyte plasma membrane that prevents further binding of sperm

Answer 6

Fast

Question 7

The __ component of the cortical rxn is the release of cortical granules containing enzymes (into PVS) that destroy sperm receptors

Answer 7

Slow

Question 8

The morula differentiates into the ___

Answer 8

Blastocyst

Question 9

The blastocyst hatches from its zona pellucida at ___ days

Answer 9

6-7

Question 10

Implantation of the blastocyst into the luminal epithelium of the endometrium is mediated by penetrating __ cells

Answer 10

Trophoblastic

Question 11

Uterine receptivity and the decidual rxn corresponds to days ___ of a regular 28-day cycle

Answer 11

20-24

Question 12

During blastocyst implantation, differentiated ___ cells invade part of the myometrium (interstitial invasion)

A reduction in the number of ___ in the epithelial cells factilitates embryo penetration

___ are apical epithelial cellular protrusions of the endometrium

Answer 12

Syncytiotrophoblastic

Desmosomes

Pinopodes

Question 13

Invasion of the endometrium and the inner third of the myometrium is determined by the action of secretory proteolytic enzymes released by the ___

___ erode the branches of the spiral uterine arteries to form spaces or lacunae of maternal blood within the syncytiotrophoblast mass

Answer 13

Syncytiotrophoblast

Proteases

Question 14

___ initiates the primitive uteroplacental circulation and represents the starting point of the future intervillous space

Answer 14

Endovascular invasion

Question 15

___ is established when trophoblastic cells are in direct contact with maternal blood

Answer 15

Uteroplacental circulation

Question 16

The ___ begins the secretion of hCG into the maternal lacunae. The secretion of estrogens and progesterone by the __ is now under the control of hCG

Answer 16

Syncytiotrophoblast

Corpus luteum

Question 17

During implantation, the ___ provides an immune-protective environment for the development of the embryo.

Production of immunosuppressive substances, mainly ___, inhibit the activation of NK cells at the implantation site

___ cells do not express MHC II and cannot present ags to maternal CD4+ T cells

Answer 17

Decidua

Prostaglandins

Syncytiotrophoblast

Question 18

At the end of the 2nd week, cytotrophoblastic cells proliferate and extend into the syncytiotrophoblast mass, forming the ___

Answer 18

Primary villi

Question 19

Early in the 3rd week, the extraembryonic mesoderm extends into the primary villi to form the ___.

In a cross section, a ___ is formed by a core of extraembryonic mesoderm surrounded by a middle cytotrophoblast layer and an outer layer of syncytiotrophoblast

Answer 19

Secondary villi

Secondary villi

Question 20

Cells of the XE mesoderm differentiate into capillary and blood cells, forming the ___

Answer 20

Tertiary villi

The difference between secondary and tertiary villi is the presence of capillaries in tertiary villi

Question 21

___ protects the fetus, provides for nutrition, respiration, excretion and hormone protection during development. It is a temporary organ with embryonic (chorionic frondosum) and maternal (decidua basalis) components

Answer 21

The placenta

Question 22

Maternal Abs, mainly ___, are taken up by the syncytiotrophoblast and then transported to fetal capillaries for passive immunity. The larger ___ molecules do not cross the placental barrier

Answer 22

IgG

IgM

Question 23

Maternal Abs against the __ ag cause hemolytic disease (erythroblastosis fetalis)

Answer 23

D

Question 24

In erythroblastosis fetalis, the fetus will be Rh___ and the mother will be Rh___

Answer 24

Fetus=Rh-positive

Mother=Rh-negative–> mom lacks the D ag

Question 25

After a Rh negative mother gives birth to the first child who is Rh positive, describe what happens in a subsequent pregnancy if mother is not treated?

Answer 25

In a subsequent pregnancy, Abs to the D ag (IgG) cross the placenta and cause hemolysis of fetal RBCs

Question 26

The fetoplacental unit produces ___ hormones

Answer 26

Steroid

Question 27

The decidua ___ is the portion underlying the implantation site and forms the maternal part of the placenta

Answer 27

Basalis

Question 28

The decidua ___ is the portion overlying the impanted embryo and separating it from the uterine cavity

Answer 28

Capsularis

Question 29

The decidua ___ is the remainder of the endometrium

Answer 29

Parietalis

Question 30

___ is the chorionic plate and villi derived from the cytotrophoblastic shell

Answer 30

Chorionic frondosum

Question 31

The ___ is the basic structure involved in maternal-fetal exchanges

Answer 31

Chorionic villus Each villus has a core of mesenchyma connective tissue and fetal BVs (arterioles and capillaries)

Question 32

___ is the premature separation of the normally implanted placenta

Answer 32

Placental abruption

Question 33

During a placental abruption, hemorrhage into the __ leads to premature placental separation and bleeding. Also, separation of the placenta from the uterus impairs ___ of the fetus

Answer 33

Decidua basalis Oxygenation

Question 34

This abnormality of placental implantation is an impantation of the placenta over the cervical os

Answer 34

Placenta previa

Question 35

This abnormality of placental implanatation is an abnormal trophoblastic invasion into the myometrium

Answer 35

Placenta accreta

Question 36

This placental implantation abnormality is when chorionic villi invade into the myometrium

Answer 36

Placenta increta

Question 37

This placental implantation abnormality is when chorionic villi invade through the serosa and into the surrounding tissues

Answer 37

Placenta percerta

Question 38

In ___, the contractions of the uterine muscles are not strong enough and postpartum bleeding occurs

Answer 38

Uterine atony

Question 39

What are some predisposing factors of uterine atony?

Answer 39

- abnormal labor - substantial enlargement of the uterus - uterine fibroids (leiomyomas)

Question 40

IV infusion of __ stimulates uterine contractions and decreases the possibility of uterine atony

Answer 40

Oxytocin

Question 41

What is one significant risk factor for placental calcification?

Answer 41

Smoking

Question 42

___ are a group of neoplasms, both benign and malignant, that arises from fetal tissue invading the maternal host.

Answer 42

Gestational trophoblastic disease--> tumors composed of trophoblastic tissue

Question 43

Malignant Gestational Trophoblastic Disease is diagnosed on the basis of elevated tumor markers, primarily ___

Answer 43

Beta-hCG

Question 44

The karyotype of this GTD is 46 XX (>90% paternal origin) or 46XY (paternal origin), has extensive hydropic villi, absent fetal tissue, and extensive trophoblastic hyperplasia with significant atypia

Answer 44

Complete mole

Question 45

The karyotype of this GTD is triploidy (>90%) or tetraploidy, maternal chromosomes are present and there is fetal tissue, has limited and focal hydropic villi, and focal with mild atypia trophoblastic hyperplasia

Answer 45

Partial mole

Question 46

This malignant GTD is an invasion into myometrium of edematous chorionic villi covered with layers of proliferative trophoblastic cells, beta-hCG is moderately elevated

Answer 46

Invasive mole

Question 47

___ is an admixture of malignant cytotrophoblast and syncytiotrophoblast, with no villi

Answer 47

Choriocarcinoma

Question 48

Fertilization must be preceded by:

Answer 48

- sperm maturation (epididymis) - sperm capacitation (female repro tract)--> physiological changes necessary to penetrate the egg: removal of some epididymal and seminal glycoproteins, increase in membrane permeability to Ca which Ca influx maximizes cAMP and increases sperm motility