divide the placenta into lobules (cotyledons); E
– the deepest layer of the decidua basalis
called the decidual plate remains after parturition and provides endometrial regeneration.
10. Each of the following statements concerning the uteroplacental circulatory
system is true, EXCEPT:
A
– fetal blood enters the placenta through the umbilical arteries; B – umbilical vessels
branch in the chorionic plate and supply the villi; C
– fetal blood returns through villous
veins that converge to form the umbilical vein; D
– fetal and maternal blood mix; E –
maternal blood circulates through intervillous spaces and returns into the venous system
through veins that communicate with the lacunae.
11. The placental barrier includes the following structures, EXCEPT:
A
– syncytiotrophoblast of chorionic villi; B – connective tissue of the decidua basalis; C –
chorionic cytotrophoblast with its basal lamina; D
– connective tissue of tertiary villi; E –
endothelium of chorionic capillaries and its basal lamina.
12. The placental barrier undergoes the following changes in pregnancy, EXCEPT:
A
– gradually disappears; B – the cytotrophoblast degenerates; C – villous connective
tissue lying between the capillaries and trophoblast thins out and disappears; D
– villous
capillaries become disposed just below the trophoblast; E
– the barrier gets thin to
facilitate product exchange.
Directions
: one or more of the given statements or completions is/are correct. Choose the
answer: A
– if only 1,2, and 3 are correct; B – if only 1 and 3 are correct; C – if only 2 and
4 are correct; D
– if only 4 is correct; E – if all are correct.
13. The human embryonic development is divided into the following periods:
(1) initial (2) embryonic (3) fetal (4) postnatal
14. The events of the first week of the human embryonic development are as
follows:
(1) fertilization (2) cleavage (3) blastula formation (4) gastrulation
15. The following statements regarding the trophoblast in implantation are true:
(1) trophoblast differentiates into cytotrophoblast and syncytiotrophoblast (2)
cytotrophoblastic cells divide, migrate outwards, fuse, and form a syncytiotrophoblast (3)
syncytiotrophoblast produces enzymes to erode the endometrium (4) syncytiotrophoblast
forms processes that invade the endometrium
16. The following statements regarding the implantation sites are true:
(1) blastocyst usually implants in the upper portion of the uterus (2) implantation in the
lower uterine portion may cause severe bleeding (3) blastocyst usually implants on the
posterior wall or rarely on the anterior wall of the uterus (4) implantation outside the uterine
cavity is called ectopic
17. The following statements regarding the amnion are true:
(1) is filled with the amniotic fluid that creates watery environment for the fetus (2) provides
mechanical defence of the fetus (3) exists and functions up to birth (4) appears in the first
week of development
18. The following statements regarding the chorion are true:
(1) its primary villi consist of the trophoblast and blood vessels (2) its secondary villi
include the trophoblast and extraembryonic mesoderm (3) its villi never contact with
maternal blood (4) intervillous spaces form the trophoblastic lacunar network
19. The following statements regarding the embryo in the second week of
development are true:
(1) the embryo appears like a bilaminar disk (2) the embryo is associated with the amniotic
vesicle and the yolk sac (3) the chorion forms the chorionic sac with a cavity (4) the
embryo is attached to the inner side of the chorion by a connecting stalk
20. The following statements regarding the human chorionic gonadotropin (hCG)
are true: