Cardiac Embryology

Question 1

Which embryologic structures of the heart gives rise to Ascending aorta and pulmonary trunk in the adult?

Answer 1

Truncus arteriosus.

Question 2

Which embryologic structures of the heart gives rise to Smooth parts (outflow tract) of the left and right ventricles in the adult?

Answer 2

Bulbus cordis.

Question 3

Which embryologic structures of the heart gives rise to Trabeculated part of left and right atria in the adult?

Answer 3

Primitive atrium.

Question 4

Which embryologic structures of the heart gives rise to Trabeculated part of left and right ventricles in the adult?

Answer 4

Primitive ventricle.

Question 5

Which embryologic structures of the heart gives rise to Smooth part of left atrium in the adult?

Answer 5

Primitive pulmonary vein.

Question 6

Which embryologic structures of the heart gives rise to Coronary sinus in the adult?

Answer 6

Left horn of sinus venosus.

Question 7

Which embryologic structures of the heart gives rise to Smooth part of right atrium (sinus venarum) in the adult?

Answer 7

Right horn of sinus venosus.

Question 8

Which embryologic structures of the heart gives rise to superior vena cava (SVC) in the adult?

Answer 8

Right common Cardinal vein and right anterior Cardinal vein.

Question 9

Which embryologic structure is localized between primitive atrium and primitive ventricle?

Answer 9

Endocardial Cushion.

Question 10

What is the first part thing that happened in the construction of the septum?

Answer 10

Septum primum grows toward endocardial cushions, narrowing foramen primum.

Question 11

If the foramen secundum forms in septum primum what happened with the foramen primum?

Answer 11

Foramen primum disappears.

Question 12

How is the foramen ovale formed?

Answer 12

Septum secundum expands and covers most of the foramen secundum. The residual foramen is the foramen ovale.

Question 13

What divides the right and left atria?

Answer 13

Septum primum and septum secundum.

Question 14

How is the blood shunted from the right atrium to the left atrium in an embryo?

Answer 14

Through the foramen ovale (of the septum secundum) and ostium secundum (of the septum primum).

Question 15

What are the 3 possible causes of an atrial septal defect?

Answer 15

1) Ostium secundum overlaps foramen ovale.
2) Absence of septum secundum.
3) Neither septum secundum nor septum primum develop.

Question 16

What structure grows to close the opening/canal between the atrial chamber and ventricular chamber into two smaller openings?

Answer 16

Superior and inferior endocardial cushion.

Question 17

What genetic abnormality is common,y associated with endocardial cushion defects?

Answer 17

Trisomy 21

Question 18

How many degrees have to turn the truncoconical swellings to form the spiral septum?

Answer 18

180 Degree.

Question 19

Name 6 different truncoconical (spiral) septum defects:

Answer 19

1) Tetralogy of Fallot.
2) Persistent Truncus arteriosus.
3) Transposition of the great vessels (RV-> Ao, LV->Pulmonary artery).
4) Dextrocardia.
5) Ventricular septal defect.
6) Fenestrae.

Question 20

What does the function of the Aortic arches?

Answer 20

Interconnected arteries that come off the Truncus arteriosus and supply the Branchial arches.

Question 21

What structure develops from the 1st aortic arch?

Answer 21

Part of the maxillary artery.

Question 22

What structure develops from the 2nd aortic arch?

Answer 22

Stapedial artery and Hyoid artery.

Question 23

What structure develops from the 3rd aortic arch?

Answer 23

Common carotid artery and proximal part of internal carotid artery.

Question 24

What structure develops from the 4th aortic arch?

Answer 24

Left - arch of adult aorta.

Right - proximal part of right subclavian artery.

Question 25

What structure develops from the 6th aortic arch?

Answer 25

Proximal part of pulmonary arteries and ductus arteriosus.

Question 26

Which vessel carries oxygenated blood from placenta to the fetus?

Answer 26

Umbilical vein.

Question 27

Which is the order of oxygenation of the highest oxygenation to lowest?

Answer 27

(Highest oxygenation) Umbilical vein, Ductus venosus, Inferior Vena Cava, Right Atrium (Lowest oxygenation).

Question 28

Which are the two pathways that the blood can follow in the right atrium?

Answer 28

1) Go to Left atrium via Foramen Ovale

2) Right ventricle and main pulmonary artery.

Question 29

Once in the main pulmonary artery which are the pathways that can follow the blood?

Answer 29

1) Go to the lungs (like in the adult circulation).

2) Go true the Ductus arteriosus

Question 30

What is the ductus arteriosus?

Answer 30

It is the fetal connection between the pulmonary trunk an the aorta.

Question 31

Which are the Areas that involve shunting?

Answer 31

Ductus Venosus (in the Liver), Foramen Ovale (between the RA-LA) and Ductus Arteriosus (between the pulmonary artery and the aorta).

Question 32

What happened with the circulation at the Birth?

Answer 32

Decreased intrathoracic pressure also the resistance in pulmonary Vasculature that resulting in more blood entering pulmonary artery and returning to LA, increased LA pressure and closer of foramen ovale.

Question 33

What medication do you give to a patient with Pulmonary Ductus Arteriosus open?

Answer 33

Indomethacin helps to close PDA. “Prostaglandins E1 and E2 kEEp PDA open”.

Question 34

What structures divides the Truncus arteriosus into the aortic and pulmonary trunks? What is the cellular origin of this structure?

Answer 34

Spiral (Aorticopulmonary) septum and Neural crest derivative.

Question 35

Which fetal vessel has the highest oxygenation?

Answer 35

Umbilical vein.

Question 36

What causes the ductus arteriosus to close?

Answer 36

Infant breathing that increased oxygenated blood in Aorta and decreased prostaglandins that resulting in closure the ductus arteriosus.

Question 37

What cause the foramen ovale to close?

Answer 37

Infant breathing decreased pulmonary vascular resistance that increases LA pressure and pushes septum primum against septum secundum.