Embryology

Question 1

Zygote

Answer 1

The fertilized ovum

Question 2

Embryo

Answer 2

Used from the first cell division up to 8 weeks

Question 3

Foetus

Answer 3

After 8 weeks of pregnancy

Question 4

Blastomeres

Answer 4

The cell resultiing from the cleaving of the fertilized oocyte.

Question 5

Morula

Answer 5

A embryo that consists of 16 cells. (day 2-4)

Question 6

Blastocyst

Answer 6

When at day 4 the blastocyst cavity forms, the embryo is called a blastocyst. It is formed by the outermost trophectoderm cells and inner cell mass (ICM)

Question 7

Embryonic disk

Answer 7

Formed in the second week of development. Consists of the epiblast and the hypoblast.

Question 8

Epiblast

Answer 8

Part of the embryonic disk. The endoderm and the mesoderm are derived from the epiblast in the 3rd week of development (gastrulation). The remaining epiblast becomes ectoderm and neural plate.

Question 9

Chorion

Answer 9

A double-layered membrane formed by the trophoblasts and the extra-embryonic mesoderm.

Question 10

Chorionic cavity

Answer 10

= extra-embryonic coelom

The cavity formed between the membranes of the extra-embryonic mesoderm in the 2nd week

Question 11

The connecting stalk

Answer 11

The site of transition between the amniotic and chorionic membranes

Question 12

Yolk sac

Answer 12

The first embryonic cavity. Formed by the the migration of hypoblast cells along the inner wall of the blastocoel to form Heuser’s membrane

Question 13

What are the three layers of the uterus?

Answer 13

1. Endometrium
2. Myometrium
3. Perimetrium

Question 14

Anencefalie

Answer 14

A defect on the top of the neural tube causing the brain to underdeveloped. This disorder is fatal.

Question 15

Spina bifida

Answer 15

Caused by a neural tube defect, causing the spinal vertebrae to close unsuccessfully around the spine.

Question 16

Specificity

Answer 16

Measures how often a test correctly generates a positive result for people who have the condition that’s being tested for.

Question 17

Specificity

Answer 17

A test’s ability to correctly generate a negative result for people who don’t have the condition that’s being tested for.

Question 18

Sertoli cells

Answer 18

Somatic cells of the testes that are essential for testis formation and spermatogenesis. Facilitate the progression of germ cells to spermatozoa via direct contact and by controlling the environment milieu within the seminiferous tubules.

Question 19

Cells of Leydig

Answer 19

Found adjacent to the seminiferous tubules in the testicle. Produces testosterone in the presence of luteinizing hormone (LH)

Question 20

Nuchal translucency (NT)

Answer 20

Sonographic appearance of a collection of fluid under the skin behind the fetal neck in the first trimester. Increased NT can be a sign of down syndrome.

Question 21

NIPT

Answer 21

The non-invasive prenatal test, a blood test for pregnant women. In the blood, the DNA of the placenta will be examined. The DNA of the placenta matches the baby’s DNA in most cases. By examining this DNA, the baby will be checked for possibly having chromosomal abnormalities.