Early Embryology Blue Boxes

Question 1

When nondisjuction occurs during an early cleavage division of a zygote and an embryo with two or more cell ines with different chromosome complements is produced

Answer 1

mosaicism

Question 2

Preimplantation genetic diagnosis can be carried out how many days after in vitro fertilization of an oocyte?

Answer 2

3 to 5 days

Question 3

Early implantation of the _____ is a critical period of development that may fail to occur

Answer 3

blastocyst

Question 4

Overall early spontaneous abortion rate

Answer 4

45%

Question 5

More than half of all known spontaneous abortions occur because of abnormalities in what?

Answer 5

chromosomes

Question 6

When blastocysts implant outside the uterus

Answer 6

ectopic pregnancy

Question 7

95% to 98% of ectopic implantations occur where?

Answer 7

uterine tubes (more often in ampulla and isthmus)

Question 8

pocket formed by the deflection of the peritoneum from the rectum to the uterus where blastocysts can commonly implant

Answer 8

rectouterine pouch

Question 9

a calcified fetus

Answer 9

lithopedion

Question 10

the placenta becomes firmly attached to fibrous and muscular tissues of the cervix

Answer 10

cervical implantation

Question 11

implantation of a blastocyst in the inferior segment of the uterus near the interal os (opening) of the cervix results in what?

Answer 11

placenta pervia (placenta that particually or completely covers os)

Question 12

early pregnancy loss

Answer 12

miscarriage

Question 13

most spontaneous abortions ob embryos occur during the first ___ weeks

Answer 13

3

Question 14

The higher incidence of early spontaneous abortions in older women probably results from the increasing frequence of?

Answer 14

nondisjunction during oogenesis

Question 15

Relatively large doses of progestins and/or estrogens (“morning after pill”) usually does not prevent fertilization but often prevents what?

Answer 15

implantation of the blastocyst

Question 16

A high dose of diethylstilbestrol does what?

Answer 16

accelerates the passage of the cleaving zygote along the uterine tube

Question 17

An intrauterine device usually interferes with implantation by causing what?

Answer 17

a local inflammatory reaction

Question 18

Symptom of pregnancy?

Answer 18

nausea/vomiting

Question 19

remnants of the primitive streak may persist and give rise to a _________

Answer 19

sacrococcygeal teratoma

Question 20

type of germ cell tumor

Answer 20

teratoma

Question 21

benign and malignant tumors that form from vestigial remnants of notochordal tissue

Answer 21

chordomas

Question 22

remnants of the extraembryonic portion of hte allantois

Answer 22

allantoic cysts

Question 23

partial absence of the brain (neural tube defect)

Answer 23

meroencephaly

Question 24

cystic swellings formed from degenerating chorionic villi

Answer 24

hydatidiform moles

Question 25

malignant trophoblastic lesions

Answer 25

choriocarcinomas