MSK_MT1_DSA3 (MSK Embryology & Development)

Question 1

Axial Skeleton Embryonic Precursors are…

Answer 1

MESODERM

1. Notochord
2. Paraxial mesoderm
3. Lateral plate mesoderm

Question 2

Axial Skeleton Development begins at….

Answer 2

• end of the 4th week
• starts with sclerotome making mesenchymal cells that can begin differentiating.

Question 3

Answer 3

Yolk Sac

Question 4

Answer 4

Amnioblasts (becomes the amniotic sac)

Question 5

Answer 5

Primitive Streak

• linear band of thickened epiblast that starts caudal end of the embryo and grows cranially.
• Disorder = Sacrococcygeal teratoma ST

Question 6

Answer 6

Primitive Node:

enlarged group of cells located in the anterior portion of the primitive streak in a developing gastrula

Question 7

Answer 7

Epiblast

the outermost layer of an embryo before it differentiates into ectoderm and mesoderm.

Question 8

Answer 8

Invaginating Mesoderm Cells

Question 9

Answer 9

Hypoblasts

• helps determine the embryo’s body axes
• its migration determines the formation of the primitive streak and the embryo’s orientation.
• yolk sac

Question 10

Notocord Development

Answer 10

• mesoderm, trilaminar embryonic disk
• differentiate into neuroectoderm
• Forms the nucleus pulposus of each spine disk

Question 11

Paraxial mesoderm

Answer 11

• thick chunk of mesoderm located on each side of the midline
• Becomes somitomeres/ somites segments