Embryo - 2

Question 1

Truncus Arteriosus

Answer 1

Pulmonary Trunk & Aorta

Question 2

Bulbus Cordis

Answer 2

conus arteriosus & aortic vestibule

Question 3

primitive ventricles

Answer 3

trabeculae carneae of ventricles

Question 4

primitive atria

Answer 4

pectinate muscle of atria

Question 5

sinus venosus (L)

Answer 5

coronary sinus

Question 6

sinus venosus (R)

Answer 6

sinus venarum and valves of the IVC & coronary sinus

Question 7

Gives rise to the cardiovascular system

Answer 7

lateral (splanchnic) mesoderm

Question 8

Ostium Primum Defect

Answer 8

septum primum does not fuse with the AV region

Question 9

ostium secundum defect

Answer 9

too much apoptosis of septum primum; or, septum secundum fails to develop

Question 10

L to R shunts: LateR cyanosis

- Eisenmenger Syndrome

Answer 10

Pulmonary HTN - resulting from VSD, ASD, or patent ductus arteriosus
leads to R –> L Shunting, cyanosis, and clubbing

Question 11

R to L Shunts: eaRLy cyanosis

Answer 11

5 T’s

• Tricuspid atresia
• total anomalous pulmonary venous return
• truncus arteriosus (persistent)
• transposition of the great vessels
• tetralogy of Fallot

Question 12

Tricuspid atresia

Answer 12

tricuspid valve and right AV canal do not develop
ALWAYS accompanied with:
-patent foramen ovale
-VSD
-underdeveloped R ventricle (pulmonary stenosis)
-L. ventricular hypertrophy

Question 13

total anomalous pulmonary venous return

Answer 13

pulmonary veins (oxygenated blood) drain into R atrium or SVC
accompanied with:
-ASD so blood reaches L side of the heart
-enlarged R side of the heart

Question 14

truncus arteriosus (persistent)
 -Neural crest migratory failure

Answer 14

aorticopulmonary septum does not form = undivided truncus arteriosus (no distinction between pulmonary trunk and aorta)

Question 15

transposition of the great vessels

-Neural crest migratory failure

Answer 15

aorticopulmonary septum does not spiral
-aorta connected to R side, pulmonary connected to L side (deoxy blood to circulation)
two separate circuits:
-blood travels from R side of heart to body and back
-blood travels from L side of heart to lungs and back

NOT COMPATIBLE WITH LIFE

Question 16

tetralogy of Fallot

-Neural crest migratory failure

Answer 16

unequal separation of the conotruncal region
4 key characteristics (PROV):
 -Pulmonary stenosis
 -R ventricle hypertrophy
   boot-shaped sign
 -Overriding aorta
 -VSD

Question 17

Aortic Arches

Answer 17

Development begins week 4-5
Arches:
-L/R Arch 3: Common and internal carotids
-L arch 4: arch of aorta
-R arch 4: R. subclavian vein
-L arch 6: L pulmonary artery and ductus arteriosus
-R arch 6: R pulmonary artery