Cardiac Development Flashcards Preview

Module 1 CHD > Cardiac Development > Flashcards

Flashcards in Cardiac Development Deck (15):
1

Sections of mesoderm (medial to lateral)

Chordomesoderm

Paraxial mesoderm

Intermedial mesoderm

Lateral plate mesoderm

2

Lateral plate mesoderm

- Anterior region forms the heart

- Posterior region forms blood

- Lateral/ventral forms myocardium

3

Foregut

Foregut endoderm is beneath and signals to induce cardiac mesoderm

4

Cardiac Crescent

- First morphologically identifiable cardiac structure

- Transforms to linear heart tube

5

Folding (22d)

- Tubular structure formed of endocardium and myocardium

- Myocardium and foregut are connected by dorsal mesocardium

- Connection is lost by apoptosis and only VA poles stay connected

6

Looping
(23-4d)

- V pole move anteriorly to meet A pole

- IFT and OFT fuse

- Chambers begin to form

- Valve precursors allow unidirectional flow

7

Septation (35d)

- Two layers of myocardium:
Trabecular (primitive)
Compact (more advanced)

- Right and left side are separated

8

Gastrulation

- Epiblasts migrate inside from the primitive streak through a slit-like structure following nodal signals

- FGF8 repels them, FGF4 attracts them

- They can become mesoderm or endoderm


9

Tinman/Nkx2.5

- Induced by BMP2

- TF that induces expression of genes in early heart field cells

- Expressed throughout entire mesoderm initially

- As mesoderm moves dorsally, expression is stronger at one pole

10

Foregut-derived inducers

- BMPs

-FGFs

- Shh

-Crescent

11

Ectoderm and notochord

- Release antagonists to prevent heart formation in other regions

12

The Second Heart Field

- Cells must migrate in to help the heart grow as FHF-derived cells do not proliferate much

-Precursors of RV and common OFT migrate

- RV entirely derived from SHF cells instructed by dHAND/Hand2

13

Define the First Heart Field

Expression

- The first wave of mesodermal cells that differentiate to form the initial heart tube. Origin of the LV.

- Express muscle-specific proteins (MLC2A/3F)

- First group to down-regulate Isl1

14

Define the Second Heart Field

- Progenitors added to the formed heart tube at the A or V pole

15

Define the Anterior Heart Field

Expression

- A region derived of the SHF restricted to the RV and OFT myocardium progenitors

- FGF10-LacZ