Embryo Development

Question 1

What happens with embryo within 1st week of development?

Answer 1

Zygote (day 1) -> Blastula (days 2-3) -> Morula (day 4) -> Blastocyst (day 6) -> Implantation (days 6-10)

Question 2

When does blastocyst implant?

Answer 2

Blastocyst sticks on day 6

Question 3

What happens with embryo within 2nd week of development?

Answer 3

Bilaminar disk (epiblast, hypoblast)
2 weeks = 2 layers

Question 4

What happens with embryo within 3d week of development?

Answer 4

Cells from epiblast form trilaminar embryonic disk (endoderm, mesoderm, ectoderm) + notochord
Overlying ectoderm becomes neural plate.

Question 5

What happens with embryo within 3-8 weeks of development?

Answer 5

Organogenesis;

Neural tube formed by neuroectoderm and closes by week 4

Question 6

What happens with embryo within 4th week of development?

Answer 6

Heart begin to beat;
Limbs begin to form.
4 weeks = 4 chambers, 4 limbs

Question 7

What happens with embryo within 6th week of development?

Answer 7

Cardiac activity on t/v ultrasound

Question 8

What happens with embryo within 8th week of development?

Answer 8

Fetal movement

Question 9

What happens with embryo within 10th week of development?

Answer 9

Genitalia have male/female characteristics

“Tenitalia”

Question 10

Which pathology is associated with fusion defect of the 3-layer tube?

Answer 10

Gastroschisis