Deck 24: Pregnancy Human Development

Question 1

Which portion of the blastocyst fuses with the endometrium?

A) Trophoblast
B) Embryonic disc
C) Yolk sac
D) Ectoderm

Answer 1

A

Question 2

Blood returns to the fetus from the placenta via the

A) umbilical arteries.
B) umbilical vein.
C) lacunae.
D) chorionic villi.

Answer 2

B

Question 3

What are the germ layers, and from what do they arise?

A) The germ layers are an inner cell mass that flattens to form the embryonic disc.
B) The germ layers are an inner cell mass that separates from the trophoblast to create the amniotic cavity.
C) The germ layers are shoots sent out by the trophoblast to gain nourishment from the endometrium.
D) The germ layers are three layers that arise from the embryonic disc and produce all the organs and tissues of the body.

Answer 3

D

Question 4

When does the fetal heart begin to beat?

A) Day 12
B) Day 22
C) 8 weeks
D) 20 weeks

Question 5

How many chromosomes does a zygote have?

A) 46
B) 46 pairs
C) 23
D) 12

Question 6

What is the name of the blackberry-like cluster of cells that enter the uterine cavity 3 to 4 days after ovulation?

A) Blastomere
B) Morula
C) Blastocyst
D) Zygote

Question 7

The stage of development that begins at fertilization and lasts for 16 days is called the

A) fetal stage.
B) zygotic stage.
C) embryonic stage.
D) pre-embryonic stage.

Question 8

Implantation typically occurs approximately

A) 3 days after fertilization.
B) 2 days after fertilization.
C) 6 days after fertilization.
D) 10 days after fertilization.

Question 9

What role is served by the ductus venosus?

A) It shunts blood from the right into the left atrium.
B) It shunts blood around the liver.
C) It shunts blood from the right ventricle to the pulmonary artery.
D) It shunts blood around the kidneys.

Question 10

Most of the organs are developed during which stage of pregnancy?

A) First trimester
B) Second trimester
C) The last week of the first trimester
D) Third trimester

Question 11

If the ductus arteriosus fails to close at birth, what symptoms would you expect to see and why?

A) Respiratory difficulty, because blood is bypassing the lungs
B) Increased levels of toxins in the blood, because blood is bypassing the liver
C) Decreased urine output, because blood is bypassing the kidneys
D) Decreased nutrition, because blood is bypassing the stomach

Question 12

The umbilical cord contains

A) two umbilical arteries and one umbilical vein.
B) two umbilical arteries and two umbilical veins.
C) one umbilical artery and one umbilical vein.
D) one umbilical artery and two umbilical veins.

Question 13

Gestation typically lasts about

A) 40 weeks.
B) 42 weeks.
C) 39 weeks.
D) 38 weeks.

Question 14

Which extraembryonic membrane serves as the foundation for the umbilical cord?

A) Amnion
B) Chorion
C) Allantois
D) Yolk sac

Question 15

What is human chorionic gonadotropin, and what does it do?

A) It is a hormone secreted by the trophoblast; it prompts the corpus luteum to secrete estrogen and progesterone.
B) It is an enzyme secreted by the trophoblast to aid implantation.
C) It is a hormone secreted by the corpus luteum to inhibit ovulation.
D) It is a hormone secreted by the placenta to help maintain the uterine lining.

Question 16

What key developmental task initiates the beginning of the embryonic stage?

A) The placenta becomes functional
B) The beginning of the fetal heartbeat
C) The formation of the germ layers
D) The development of a yolk sac

Question 17

Which statement about the amnion is accurate?

A) The amnion is filled with fluid that supplies the embryo with nutrition.
B) The amnion begins to develop at the time of conception.
C) The fetus "breathes" and swallows the fluid in the amniotic sac.
D) The fluid volume in the amnion remains stable because it is fed by the maternal blood supply.

Question 18

Which of the following statements about the placenta is correct?

A) Oxygenated blood flows from the placenta to the fetus through the umbilical arteries.
B) Maternal and fetal blood mix in the placenta.
C) The placenta secretes hormones necessary for the continuation of pregnancy.
D) The placenta effectively screens nicotine, alcohol and most drugs, thus protecting the fetus.

Question 19

Which extraembryonic membrane eventually forms the fetal side of the placenta?

A) Amnion
B) Chorion
C) Allantois
D) Yolk sac

Question 20

The mesoderm gives rise to

A) cardiac muscle.
B) the epidermis.
C) the nervous system.
D) the thyroid gland.

Question 21

During lactation, the release of which hormone forces milk into the ducts?

A) Prolactin
B) Oxytocin
C) Estrogen
D) Progesterone

Question 22

Which of the following statements about the first stage of labor is correct?

A) It is the shortest stage of labor.
B) It begins after the rupture of fetal membranes.
C) It is the stage in which the top of the baby's head first appears.
D) It ends when the cervix is fully dilated.

Question 23

The stage of development that begins the third week of gestation and lasts until the eighth week is called the ____________________ stage.

Question 24

The fine hair covering the fetus's body is called ____________________.

Question 25

Fetal movement can usually be felt about

A) day 20.
B) week 12.
C) week 20.
D) week 32.

Question 26

Which of the following is one of the factors thought to contribute to the onset of labor?

A) An increase in progesterone
B) A decline in estrogen
C) The release of oxytocin
D) Fetal movement

Question 27

When is the fetal respiratory system first capable of gas exchange?

A) Week 20
B) Week 28
C) Week 12
D) Week 32

Question 28

The layer of cells and gel-like membrane encasing the ovum is called the ____________________.

Question 29

A fertilized egg is called a ____________________.

Question 30

The progressive thinning of the cervical walls is called cervical ____________________.

Question 31

A woman giving birth for the first time is called a ____________________.

Question 32

The inner group of cells of the blastocyst becomes the ____________________, and the outer group of cells becomes the ____________________.

Question 33

The second stage of labor ends when

A) the membranes rupture.
B) the cervix is fully effaced.
C) the baby is born.
D) the placenta is delivered.

Question 34

The stage of development that begins the eighth week and lasts until birth is called the ____________________ stage.

Question 35

Shortly after fertilization, the fertilized cell divides by ____________________, a process called ____________________, to produce two identical daughter cells.

Question 36

Late in pregnancy, the uterus normally exhibits weak, irregular contractions called ____________________ contractions, or "false labor."