Tissue Origins In Development

Question 1

4 essential processes in development

Answer 1

Cell proliferation
Cell specialisation
Cell interaction
Cell movement

Question 2

2 proteins important for multicellular interaction

Answer 2

Cell adhesion & signalling
Gene regulatory proteins

Question 3

Types of morphogens

Answer 3

Growth factors
Chemokines
Contact mediated morphogens
Other secreted factors eg Hedgehog proteins

Question 4

Cells know where they are because:

Answer 4

Cell-cell interactions
Gradients of signal molecules diffusing from the source

Question 5

Germ layer composed of:

Answer 5

Ectoderm
Mesoderm
Endoderm

Question 6

Bilaminar disc contains

Answer 6

Epiblast & hypoblast cells

Question 7

Regulation of gastrulation

Answer 7

Epiblast cells induced by primitive node & primitive streak, & migrate to molecular signals
Loss of E cadherin allows Epiblast cells to dissociate & undergo phenotypic changes to become Mesenchymal cells - EMT

Question 8

EMT - As Epiblast cells migrate towards primitive streak they:

Answer 8

Loss E cadherin
Produce mesenchymal phenotype

Question 9

Epithelial cells

Answer 9

Well differentiated polarised cells
Apical & basal surface
Close connections w/ adjacent cells through tight & gap junctions & desmosomes

Question 10

Mesenchymal cells

Answer 10

Mobile
Not closely connected to adjacent cells
In contact w/ surrounding ECM through focal adhesions

Question 11

Examples of Ectoderm

Answer 11

CNS
PNS
Epidermis

Question 12

Examples of Mesoderm

Answer 12

Connective tissue
Muscle
Spleen

Question 13

Examples of Endoderm

Answer 13

Epithelial lining of GIT
Liver
Pancreas