Coding 22 Flashcards
What does the epiblast make?
Primitive endoderm
What is the primitive endoderm?
Cells crucial for gastrulation and the formation of the trophoblast
What is sox17?
A marker for endoderm formation
What does sox17 allow you to detect?
Cells that ingress through the primitive streak
What induces sox17?
High nodal
What represses sox17?
BMP and FGF
What are the 3 regions that are defined next to the gut endoderm?
- Midgut/hindgut
- Central endoderm region
- Head endoderm
What happens at the 22-day human embryo mark?
The oral opening of the digestive tube forms due to the oral plate breaking
What are pharyngeal arches?
These are the pairs of endoderm that form from pharyngeal pouches
What is between the pharyngeal pouches?
Pharyngeal floor plate
What happens to the mesenchyme cells during the formation of the endodermal tube?
The mesenchyme cells wrap around the endoderm
What is the heaptic diverticulum?
It extends from the foregut and surrounds the mesenchyme and induces endoderm proliferation
Where does the liver form?
Below the notochord
What induces liver formation?
FGF from the heart and endolethial cells
What leads to competence of the liver formation?
FoxA1 and FoxA2 receptors that receive the signals
What induces pancreas formation?
The notochord
What does the notochord do to induce pancreas formation?
Repress SHH
What role does FGF2 play?
It represses the SHH
Where are the lungs derived from?
Digestive tube
What builds up to form the lungs?
Beta catenin
What is the Wnt/FGF/BMP level in the head endoderm?
Low
What is the Wnt/FGF/BMP level in the posterior endoderm?
High
What is the Wnt/FGF/BMP levels in the central endoderm?
Moderate
Where is sox17 active?
In the endoderm
Where is SHH not expressed?
Where the pancreas forms
What leads to the lung formation from the digestive tube?
Beta catenin build up
