Lec 30: Cardiac Development and Malformations

Question 1

What are the adult derivatives of first heart field cells?

Answer 1

Mainly left ventricle

Question 2

What are the adult derivatives of the second heart field cells?

Answer 2

anterior SHF = outflow tract

posterior SHF = sinus venosus, atria and right ventricle

Question 3

What are the adult derivatives of cranial (cardiac) neural crest?

Answer 3

Aorticopulmonary septum and parasympathetic neurons

Question 4

What are the adult derivatives of proepicardial cells near the caudal end of the heart tube?

Answer 4

Epicardium, heart fibroblasts, coronary vessels

Question 5

What does the embryonic right sinus venosus and sinus horn become in adult?

Answer 5

Smooth wall of the right atrium

Question 6

What does the embryonic left sinus venosus and sinus horn become?

Answer 6

Coronary sinus

Question 7

What does the embryonic primitive atrium become in adult?

Answer 7

Adult trabeculated parts of atria

Question 8

What does the embryonic primitive left ventricle become in adult?

Answer 8

left ventricle

Question 9

What does the embryonic bulbus cordis become in adult?

Answer 9

right ventricle and outflow regions

Question 10

What does the embryonic conus cordis (the upper bulbus cordis) become in adult?

Answer 10

outflow regions of ventricles

Question 11

What does the embryonic truncus arteriosus become in adult?

Answer 11

Ascending aorta and pulmonary trunk

Question 12

What are the 4 components of tetralogy of Fallot, and generally what causes it?

Answer 12

1. pulmonary stenosis
2. overriding aorta
3. ventricular septal defect
4. hypertrophy of the right ventricle

caused because of misaligment of aorticopulmonary septum such that pulmonary outflow tract is abnormally small and aortic outflow tract abnormally large

Question 13

What are the embryonic components of the atrioventricular canal, what disorders may be present, and what molecules may be important?

Answer 13

• endocardial cushions and secondary heart field cells
• atrioventricular septal defect
• Shh, Tbx5

Question 14

What are the embryonic components of the atrial septum, what disorders may be present, and what molecules are linked?

Answer 14

4 components:

1) septum primum
2) dorsal mesenchymal protrusion (DMP)
3) septum secundum
4) endocardial cushions
- atrial septal defect
- Shh, Tbx5

Question 15

What are the embryonic components of the ventricular septum, what disorders may be present, and what molecules are linked?

Answer 15

• muscular interventricular septum
• membranous interventricular septum (from conal and AV cushions)
• ventricular septal defect
• Tbx1

Question 16

What are the embryonic components of the truncal septum, what disorders may be present, and what molecules are linked?

Answer 16

• truncal cushions, neural crest, secondary heart field cells
• persistent truncus arteriosus (lack of separation of aortic and pulmonary trunks)
• tetralogy of Fallot
• transposition of the great vessels
• Tbx1, Pitx2, RA

Question 17

What molecule gives rise to left ventricular identity?

Answer 17

Tbx5