Chapter 3: Week 2

Question 1

Which of the following components plays the most active role in invading the endometrium during blastocyst implantation? (A) Epiblast (B) Syncytiotrophoblast (C) Hypoblast (D) Extraembryonic somatic mesoderm (E) Extraembryonic visceral mesoderm

Answer 1

(B) Syncytiotrophoblast

Question 2

Between which two layers is the extraem- bryonic mesoderm located? (A) Epiblast and hypoblast (B) Syncytiotrophoblast and cytotrophoblast (C) Syncytiotrophoblast and endometrium (D) Exocoelomic membrane and syncytiotrophoblast (E) Exocoelomic membrane and cytotrophoblast

Answer 2

(E) Exocoelomic membrane and cytotrophoblast

Question 3

During week 2 of development, the embryoblast receives its nutrients via (A) diffusion (B) osmosis (C) reverse osmosis (D) fetal capillaries (E) yolk sac nourishment

Answer 3

(A) diffusion

Question 4

The prochordal plate marks the site of the future (A) umbilical cord (B) heart (C) mouth (D) anus (E) nose

Answer 4

(C) mouth

Question 5

Which of the following are components of the definitive chorion? (A) Extraembryonic somatic mesoderm and epiblast (B) Extraembryonic somatic mesoderm and cytotrophoblast (C) Extraembryonic somatic mesoderm and syncytiotrophoblast (D) Extraembryonic somatic mesoderm, cytotrophoblast, and syncytiotrophoblast (E) Extraembryonic visceral mesoderm, cytotrophoblast, and syncytiotrophoblast

Answer 5

(D) Extraembryonic somatic mesoderm, cytotrophoblast, and syncytiotrophoblast

Question 6

A 16-year-old girl presents on May 10 in obvious emotional distress. On questioning, she relates that on May 1 she experienced sexual intercourse for the first time, without using any means of birth control. Most of her anxiety stems from her fear of pregnancy. What should the physician do to alleviate her fear? (A) Prescribe diazepam and wait to see if she misses her next menstrual period (B) Use ultrasonography to document pregnancy (C) Order a laboratory assay for serum hCG (D) Order a laboratory assay for serum progesterone (E) Prescribe diethylstilbestrol (“morning- after pill”)

Answer 6

(C) Order a laboratory assay for serum hCG

Question 7

Carcinoembryonic antigen (CEA) is an oncofetal antigen that is generally associated with which one of the following tumors? (A) Hepatoma (B) Germ cell tumor (C) Squamous cell carcinoma (D) Colorectal carcinoma (E) Teratocarcinoma

Answer 7

(D) Colorectal carcinoma

Question 8

A 42-year-old woman presents with complaints of severe headaches, blurred vision, slurred speech, and loss of muscle coordination. Her last pregnancy 5 years ago resulted in a hydatidiform mole. Laboratory results show a high hCG level. Which of the following conditions is a probable diagnosis? (A) Vasa previa (B) Placenta previa (C) Succenturiate placenta (D) Choriocarcinoma (E) Membranous placenta

Answer 8

(D) Choriocarcinoma

Question 9

At what location does the amniotic cavity develop? (A) Between the cytotrophoblast and syncytiotrophoblast (B) Within the extraembryonic mesoderm (C) Between the endoderm and mesoderm (D) Within the hypoblast (E) Within the epiblast

Answer 9

(E) Within the epiblast

Question 10

At the end of week 2 of development (day 14), what is the composition of the embryonic disk? (A) Epiblast only (B) Epiblast and hypoblast (C) Ectoderm and endoderm (D) Ectoderm, mesoderm, and endoderm (E) Epiblast, mesoderm, and hypoblast

Answer 10

(B) Epiblast and hypoblast

Question 11

1. Future site of the mouth
2. Forms definitive structures found in the adult
3. Chorion
4. Chorionic cavity
5. Primary chorionic villi
6. Connecting stalk

Answer 11

1. E
2. C
3. D
4. G
5. A
6. B
7. Future site of the mouth
8. Forms definitive structures found in the adult
9. Chorion
10. Chorionic cavity
11. Primary chorionic villi
12. Connecting stalk