Chapter 3 Lecture 6-8

Question 1

What tissue from the implanting embryo directly interfaces with the endometrial connective tissue?

A. Corona radiata

B. Inner cell mass

C. Extraembryonic mesoderm

D. Epiblast

E. Synctiotrophoblast

Answer 1

E. Synctiotrophoblast

Question 2

Identical twinning is made possible by what process or property of the early embryo?

A. Regulation

B. Aneuploidy

C. Paternal imprinting

D. Maternal imprinting

E. X-chromosomal inactivation

Answer 2

A. Regulation

Question 3

The zone pellucida:

A. Aids in penetration of the endometrial epithelium

B. Serves as a source of nutrients for the embryo

C. Prevents premature implantation of the cleaving embryo

D. All of the above

E. None of the above

Answer 3

C. Prevents premature implantation of the cleaving embryo

Question 4

What is the importance of the inner cell mass of the cleaving embryo?

Answer 4

The embryonic body proper arises from the inner cell mass.

Question 5

Parental imprinting is a phenomenon showing that certain homologous maternal and paternal chromosome have different influences on the development of the embryo. Excess paternal influences result in the abnormal development of what type of tissue at the expense of development of the embryo itself?

Answer 5

Trophoblastic tissues

Question 6

What is the function of integrins in implantation?

Answer 6

They allow the trophoblast of the embryo to adhere to the uterine epithelium.

Question 7

What is the cellular origin of the synctiotrophoblast of the implanting embryo?

Answer 7

Cells derived from the cytotrophoblast fuse to form the synctiotrophoblast.

Question 8

A woman who is 2-3 months pregnant suddenly develops severe lower abdominal pain. In the differential diagnosis, the physician must include the possibility of what condition?

Answer 8

In addition to the standard causes of lower abdominal pain, such as appendicitis, the physician should consider ectopic pregnancy (tubal variety) as a result of stretching and possible rupture of the uterine tube containing the implanted embryo.

Question 9

What is the most common condition associated with spontaneously aborted embryos?

A. Maternal imprinting

B. Paternal imprinting

C. Ectopic pregnancy

D. Chromosomal abnormalities

E. Lack of X-chromosomal inactivation

Answer 9

D. Chromosomal abnormalities