Embryology: Week 3

Question 1

So in week 3, the majority of the cell division starts to occur. What is the first structures to start to develop?

Answer 1

Gastrulation occurs in week 3 (true ectoderm, endoderm, mesoderm formation).

The first structure is the brain and spinal cord

Question 2

What cell tissues are considered ectoderm derived?

Answer 2

Skin, hair, nails, the CNS (brain + spinal cord)

Question 3

What cell tissues are considered mesoderm derived?

Answer 3

bone, blood, heart, spleen

Question 4

What cell tissues are considered endoderm derived?

Answer 4

lungs, GI tract organs, bladder, glands, thyroid, parathyroid

Question 5

What is the primitive groove and what is its function in embryogenesis?

Answer 5

The primitive streak will give rise to the true mesoderm and endoderm of the cell.

Question 6

What structure makes the future diaphragm from the epiblast?

Answer 6

Septum transversum:

creates the diaphragm and comes from the rostral portion of the epiblast

Question 7

What structure makes the heart of the epiblast?

Answer 7

The cardiogenic area of the rostral part of the epiblast

Question 8

What part makes the mouth and anus of the embryo?

Answer 8

The prechordal plate which will be from only ectoderm and endodermal layers

Question 9

What structure creates the urinary system, digestive system, and reproductive system

Answer 9

The cloacal membrane which is both endoderm and ectoderm