Lecture 4

Question 1

Cell Internalization

Answer 1

Gastrulation: change from ball of cells to embryo with gut and 3 layers
- Ectoderm: epidermis and nervous system
- Mesoderm: muscles, connective tissue, bones, blood, kidney
Endoderm: Guts, lungs, pancreas, liver
- Ingression: Individual cells detach from outer cell layer and migrate in(epithelial to mesenchymal), Delamination: Cells form a new cell layer -> mesoderm
- Invagination: attached cells in epithelial cell sheet pulled into middle of embryo, Involution: Cells curl and grow -> endoderm

Question 2

Elongation

Answer 2

• Cells can move as individuals or groups to form different shapes: migration
• Chain type migration involve less adherent cells
• Sheet type migration involve more adherent cells

Question 3

Cell Migration

Answer 3

• Whole cells migrate to tip of radial glial cell
• First born neurons are in deeper layer, last born in outer layer