Cardiac Development Highlights

Question 1

When does embryo vascular system begin to develop? Why?

Answer 1

Middle of the 3rd week when the embryo is no longer able to obtain nutrients by diffusion

Question 2

Dextrocardia

Answer 2

displacement of the heart to the right as a result of heart tube bending to the left instead of the right

Question 3

Ectopia Cordis

associated w/

Answer 3

heart being exposed on the surface of the thorax

associated w/ patent pericardium

Question 4

Probe Patent Foramen Ovale

Answer 4

foramen ovale big enough for a probe to be passed through

result of incomplete adhesion b/w flap of foramen ovale & septum secundum

Question 5

Secundum type ASD

Answer 5

septum primum & septum secundum defects

Question 6

What is one of the most common types of septum defects?

Answer 6

Secundum type ASD

Question 7

Endocardial Cushion defect w/ primum ASD

Answer 7

endocardial cusions fail to completely fuse

results in patent foramen primum & central heat defect

Question 8

What fails to form as a result of patent ductus arteriosus?

Answer 8

ligamentum arteriosum

Question 9

Membranous Septal Defects

Answer 9

interventricular foramen doesn’t close

Question 10

Persistent truncus arteriosus:

What fails to form?
Result?
Symtoms?

Answer 10

aorticopulmonary septum fails to form

Single vessel will give rise to pulmonary trunk and descending aorta

Result: mixing of oxygenated and deoxygenated blood

Severe cyanosis

Question 11

Embryological cause of ectopia cordis

Answer 11

failed fusion of lateral body wall folds in the midline

Question 12

Abnormal neural crest cell migration symptoms

Answer 12

enlarged right ventricle
“boot” shaped heart
cyanosis

Question 13

venous type ASD

Answer 13

defects along superior aspect of IA septum

Question 14

aorticopulmonary septal defect

Answer 14

opening in the septum (aortic window)

Question 15

Abnormal septation of the sinus venosus symptoms

Answer 15

cyanosis, tachycardia

Question 16

sinus venosus

Answer 16

deficiency of atrial septum

Question 17

Patent Ducts Arteriosus

Associated w/ what infection?

Answer 17

failure of the ductus arteriosus to close so blood is shunted to the pulmonary trunk

Rubella

Question 18

Transposition of the great vessels

Associated w/ what maternal disease?

Answer 18

aorta arises from the right ventricle, pulmonary trunk arises from the L ventricle

associated with maternal diabetes

Question 19

Tetralogy of Fallot

Associated with what disease?

Answer 19

associated group of cardiac defects (POVR’t)

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

DiGeorge Syndrome

Question 20

Most frequent cardiac defect?

Answer 20

ventricular septum defects

Question 21

Ventricular septal defect

Clinical implication?

Answer 21

hole in the septum that separates the R and L ventricles

VSD allows oxygen rich and poor blood to mix

Question 22

3rd aortic arch gives rise to

Answer 22

carotid arteries (common, external, internal)

Question 23

4th aortic arch gives rise to

Answer 23

aorta and subclavian arteries

Question 24

How is coarction combated?

Answer 24

administering of prostaglandin E2

Question 25

Most significant tetralogy of fallot symptom?

Answer 25

cyanosis

Question 26

Coarction effect on pulses

Answer 26

postductal leads to weaker pulses in the lower extremities

normal radial pulses and delayed femoral pulses & pressure will be detected

Question 27

What CVD is associated with maternal rubella?

Answer 27

pulmonary artery stenosis

patent ductus stenosis

Question 28

Removal of cardiac neural crest cells before migration

Answer 28

impairs cardiac looping; conotruncal septation is incomplete

Question 29

Ablation of cardiac neural crest cells

Answer 29

causes persistent truncus arteriosis, tricuspid stenosis, VSD, transposition of great vessels, and tetralogy of fallot

Question 30

When does the embryo vascular system begin to develop?

Answer 30

In the middle of the 3rd week when it’s no longer able to obtain nutrients by diffusion

Question 31

What are the great vessels?

Answer 31

vitelline vessels 
umbilical vessels 
cardinal vein 
dorsal aorta 
endocardial heart tube

Question 32

cardinal vein f(x)

Answer 32

drain blood from the embryo proper

Question 33

endocardial heart tubes

where do they develop?

what will they become? how?

Answer 33

in lateral splanchnic mesoderm

will form the heart
by fusing during transverse folding of the embryonic disc

Question 34

Primitive cardiogenic area

Answer 34

a horseshoe shaped plexus with mesoderm that undergoes angiogenesis

Question 35

sinus venosus f(x)

Answer 35

venous inflow channels

Question 36

Heart rotation

Answer 36

90 degrees counter clockwise simultaneously with bulboventricular looping

Question 37

Endocardial cushion f(x)

Answer 37

divide the AV canal into the right and left AV canal

Question 38

Septum Primum

Answer 38

crescent shaped membrane that grows from roof & posterior wall of primitive atrium toward the endocardial cushions

Question 39

What is the “flap” that closes the foramen ovale?

Answer 39

septum primum

Question 40

How does the foramen ovale close?

Answer 40

elevated L atrial pressure forces the septum primum against the septum secundum, closing the foramen ovale

Question 41

What closes the ductus arteriosus?

Answer 41

indomethacin (NSAID)

Question 42

Which type of VSD is the most common?

Answer 42

membranous ventricular septal defect (VSD)

Question 43

Angiogenesis

Answer 43

formation of blood vessels from existing vessels

Question 44

Describe the process of angiogenesis in the development of primitive circulation

Answer 44

angioblasts proliferate and aggregate into blood islands

Question 45

What are hemangioblasts? What will they differentiate into?

Answer 45

cells that develop from endothelial cells that will differentiate into hemocytoblasts