Embryology Flashcards
Zygote
The fertilized ovum
Embryo
Used from the first cell division up to 8 weeks
Foetus
After 8 weeks of pregnancy
Blastomeres
The cell resultiing from the cleaving of the fertilized oocyte.
Morula
A embryo that consists of 16 cells. (day 2-4)
Blastocyst
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)
Embryonic disk
Formed in the second week of development. Consists of the epiblast and the hypoblast.
Epiblast
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.
Chorion
A double-layered membrane formed by the trophoblasts and the extra-embryonic mesoderm.
Chorionic cavity
= extra-embryonic coelom
The cavity formed between the membranes of the extra-embryonic mesoderm in the 2nd week
The connecting stalk
The site of transition between the amniotic and chorionic membranes
Yolk sac
The first embryonic cavity. Formed by the the migration of hypoblast cells along the inner wall of the blastocoel to form Heuser’s membrane
What are the three layers of the uterus?
- Endometrium
- Myometrium
- Perimetrium
Anencefalie
A defect on the top of the neural tube causing the brain to underdeveloped. This disorder is fatal.
Spina bifida
Caused by a neural tube defect, causing the spinal vertebrae to close unsuccessfully around the spine.
Specificity
Measures how often a test correctly generates a positive result for people who have the condition that’s being tested for.
Specificity
A test’s ability to correctly generate a negative result for people who don’t have the condition that’s being tested for.
Sertoli cells
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.
Cells of Leydig
Found adjacent to the seminiferous tubules in the testicle. Produces testosterone in the presence of luteinizing hormone (LH)
Nuchal translucency (NT)
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.
NIPT
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.
