13.10 Implantation and the Placenta

Question 1

What is implantation?

Answer 1

developing blastocyst enters the uterus and burrows in the endometrium

Question 2

What is required to allow the blastocyst to sink into the endometrium?

Answer 2

trophoblast must secrete proteases that lyse endometrial cells

Question 3

What provides nutrients to the blastocyst initially after implantation?

Answer 3

endometrium

Question 4

What is the placenta?

Answer 4

organ that is specialized to facilitate exchange of nutrients, gases, and antibodies between maternal and embryonic bloodstreams

Question 5

How long does it take for the placenta to develop?

Answer 5

three months

Question 6

What are placental villi?

Answer 6

chorionic projections extending into the endometrium into which fetal capillaries will grow

Question 7

What are the four structures that are derived from inner mass cells?

Answer 7

embryo
amnion
yolk sac
allantois

Question 8

What is the amnion?

Answer 8

surrounds a fluid filled cavity containing the developing embryo

Question 9

What is the purpose of the yolk sac?

Answer 9

first site of red blood cell synthesis in the embryo

Question 10

What is the allantois?

Answer 10

develops from the embryonic gut and forms the blood vessels of the umbilical cord which transports blood between the embryo and placenta