Early Cardio Embryology Flashcards Preview

Term I: Embryology > Early Cardio Embryology > Flashcards

Flashcards in Early Cardio Embryology Deck (26):
1

A subset of what germ layer will be the precursor of most cells of the mature heart?

Precardiac mesoderm

2

What determines a precardiac cell's fate?

Timing and entry point through the primitive streak, local proteins and transcription factors, environment (stress, hypoxia)

3

What layer provides precursors for portions of both myocardium and endocardium?

Lateral splanchnic mesoderm

4

What process consists of blood vessels arising from blood islands?

Vasculogenesis

5

What process consists of blood vessels sprouting from existing vessels?

Angiogenesis

6

What fuses to form the cardiogenic crescent? What happens at this crescent?

Primary heart fields fuse - this is where specific cells are segregated to their specific locations

7

What do cells of the first heart field form? What do they express?

Linear heart tube, left ventricle

Tbx5

8

What do cells of the second heart field (pharyngeal mesoderm) migrate to? What do they form? What do they express?

Migrate to cranial poles of heart tube

Outflow tracts, right ventricle, inflow tracts

Isll, Tbx1

9

What does third heart field give rise to? What do they express?

Horns of sinus venosus and periphery of inflow tract

Tbx18

10

After how many days does the heart tube begin to beat?

21-22 days

11

What does the truncus anteriosus segment of the primitive heart tube form?

Aortic and pulmonary trunks

12

What does the outlet segment of the primitive heart tube form?

Inlet and apical right ventricle; both outlets

13

What does the inlet segment of the primitive heart tube form?

Inlet and apical left ventricle

14

What does the atrium segment of the primitive heart tube form?

Atrial appendages

15

What does the sinus venosus segment of the primitive heart tube form?

Proximal SVC/IVC, smooth portion of right atrium

16

What types of genes are key in differentiation of multipotent precardiac cells? Name the specific gene in vertebrates.

Homeobox genes
Nkx2.5

17

What does Nkx2.5 activate?

Myocyte enhancement factors that control myocyte differentiations

18

Name the cranial to caudal ordering of precardiac cell migration through the primitive streak.

Those migrating first form outflow tracts, then RV, LV, primitive atrium, sinus venosus

19

What types of proteins inhibit heart formation?

WNT

20

What type of looping does the linear heart tube undergo in vertebrates?

Rightward (D-looping)

21

What type of bHLH transcription factors are primarily expressed by right ventricular segments?

HAND 2

22

What type of bHLH transcription factor is primarily expressed by left ventricular segments?

HAND1

23

Deletion of what gene results in right ventricular hypoplasia?

HAND2

24

Describe the direction in which the cephalic portion of the linear heart tube bends.

Ventrally, caudally, to the right

25

Describe the direction in which the atrial/caudal portion bends.

Dorso-cranially and to the left

26

What convergence results due to looping?

Convergence of inflow (venous) and outflow (Arterial) ends