Week 12

Question 1

What are the 4 basic stages of embryological development?

Answer 1

1. Fertilisation.
2. Zygote.
3. Morula.
4. Blastocyst.

Question 2

What is fertilisation?

Answer 2

Fusion of haploid gametes (egg and sperm) to form the diploid zygote.

Question 3

What is a zygote?

Answer 3

A eukaryotic cell formed by a fertilisation event between two gametes.

Question 4

What is a morula?

Answer 4

Early-stage embryo.

Question 5

What is a blastocyst?

Answer 5

Structure formed in the early development of mammals.

Question 6

What is a diploid cell?

Answer 6

A cell that contains two complete sets of chromosomes.

Question 7

What are the 3 main components of a blastocyst?

Answer 7

1. Trophoblast.
2. Blastocyst cavity.
3. Embryoblast.

Question 8

What are the 3 main components of a blastocyst?

Answer 8

1. Trophoblast - Outer layer.
2. Blastocyst cavity.
3. Embryoblast - Inner cell mass.

Question 9

What are embryoblasts?

Answer 9

True embryonic stem cells that are attached to the blastocyst wall.

Question 10

What are the 2 layers the embryoblast develops into?

Answer 10

1. Bilaminar embryonic disk.

2. Amniotic cavity.

Question 11

What is implantation in embryology?

Answer 11

The stage of human reproduction at which the embryo adheres to the endometrium, occurs about 7 days after fertilisation.

Question 12

What is gastrulation?

Answer 12

A phase early in the embryonic development where the bilaminar embryonic disk develops into the trilaminar disk.

Question 13

What are the 3 trilaminar layers called?

Answer 13

1. Ectoderm.
2. Mesoderm.
3. Endoderm.

Question 14

What are the 4 main embryological membranes that support development?

Answer 14

1. Yolk sac.
2. Amnion.
3. Allantois (becomes bladder).
4. Chorion (becomes placenta).

Question 15

What is the function of the yolk sac?

Answer 15

Important site of blood formation.

Question 16

What is the function of the amnion?

Answer 16

Encloses the fluid that surrounds developing embryo.

Question 17

How long is each of the 3 trimesters in human pregnancy?

Answer 17

13 weeks. (40 weeks total roughly)

Question 18

What occurs in the trimester 1 of human pregnancy?

Answer 18

1. Embryonic and fetal development.

2. All major organ systems appear.

Question 19

What occurs in trimester 2 of human pregnancy?

Answer 19

1. Organ system development.

2. Fetus looks human at end of this stage.

Question 20

What occurs in trimester 3 of human pregnancy?

Answer 20

1. Growth phase and maturation.

Question 21

After how many weeks do babies have a significantly higher chance of surviving?

Answer 21

35 weeks.

Question 22

What maternal changes are expected during pregnancy?

Answer 22

Increases in:

1. Respiratory rate.
2. Tidal volume.
3. Blood volume.
4. Nutrient and vitamin intake.
5. Kidney filtration rate.

Question 23

List the uterine changes during pregnancy.

Answer 23

1. Progesterone inhibits uterine muscle contraction.
2. Oxytocin, estrogens, prostaglandins excite uterine activity.
3. Multiple factors and timing interact to produce contractions leading to labour.

Question 24

List the stages of involved in labour.

Answer 24

1. Uterus moves inferiorly.
2. Contractions and cervix dilation.
3. Expulsion.
4. Placenta is expulsed.