CV embryology

Question 1

What does the following embryonic structure give rise to?

Truncus arteriosus

Answer 1

Ascending aorta and pulmonary trunk

Question 2

What does the following embryonic structure give rise to?

Bulbus cordis

Answer 2

Smooth parts (outflow tract) of left and right ventricles

Question 3

What does the following embryonic structure give rise to?

Endocardial cushion

Answer 3

Atrial septum, membranous interventricular septum; AV and semilunar valves

Question 4

What does the following embryonic structure give rise to?

Primitive atrium

Answer 4

Trabeculated part of left and right atria

Question 5

What does the following embryonic structure give rise to?

Primitive ventricle

Answer 5

Trabeculated part of left and right ventricles

Question 6

What does the following embryonic structure give rise to?

Left horn of sinus venosus

Answer 6

Coronary sinus

Question 7

What does the following embryonic structure give rise to?

Right horn of sinus venosus

Answer 7

Smooth part of right atrium (sinus venarum)

Question 8

What does the following embryonic structure give rise to?

Right common cardinal vein and right anterior cardinal vein

Answer 8

Superior vena cava

Question 9

Ascending aorta and pulmonary trunk originate from what embryonic structure?

Answer 9

Truncus arteriosus

Question 10

The smooth part of left atrium originate from what embryonic structure?

Answer 10

primitive pulmonary vein

Question 11

The atrial septum, membranous interventricular septum; AV and semilunar valves originate from what embryonic structure?

Answer 11

Endocardial cushion

Question 12

What two structures develop from the embryonic sinus venosus?

Answer 12

coronary sinus and smooth part of right atrium (sinus venarum)

Question 13

During embryonic septation of the chambers, the foramen ovale is formed by the residual bits of what structure?

Answer 13

Foramen secundum

Question 14

Why does the foramen ovale usually close soon after birth?

Answer 14

Increased LA pressure

Question 15

Does the growth of endocardial cushions separate the atria from the ventricles?

Answer 15

Yep

Question 16

Where does the membranous portion of the interventcular septum come from?

Answer 16

Endocardial cushions.

Question 17

What is the most common congenital cardiac anomaly?

Answer 17

Ventricular septal defect

Question 18

Where do VSDs occur?

Answer 18

The membranous septum

Question 19

What the heck is the ductus arteriosus?

Answer 19

Funny you ask… fetuses don’t depend on their lungs much, so this structure allows blood to flow from the pulmonary trunk to the aorta, bypassing the lungs.

Question 20

Blood from what vessel jets through the foramen ovale to the left atria?

Answer 20

IVC

Question 21

What do we call an incomplete fusion of the foramen ovale?

Answer 21

“probe patent” foramen ovale

Question 22

The foramen ovale becomes what structure? What do we call the upper edge of this structure?

Answer 22

Fossa ovalis and the limbus of the fossa ovalis.

Question 23

Days after birth, the ductus arteriosus becomes closed off, leaving a fibrous cord we call….

Answer 23

ligamentum arteriosum!

Question 24

You check on a newborn a week after delivery and detect a machine-like murmur throughout the cardiac cycle. What’s going on?

Answer 24

The ductus arteriosus did not close, i.e. is patent. Result is reversed blood flow through ductus, bringing higher pressure from the aorta into the lower pressure pulmonary circulation.

Question 25

Cardiac jelly?

Answer 25

aceullular mass between the myocardium and endothelium that acculumates at the AV junction and leads to endocardial cushions and AV valves.

Question 26

List the swellings of the heart tube caudal to cranial

Answer 26

sinus venosus, primitive atrium, primitive ventricle, bulbus cordis, and truncus arteriosus

TA
BC
PV
PA
SV

Question 27

What would happen if septum secundum was too short and did not fully cover ostium secundum?

Answer 27

Secundum type atrial septal defect – most common type of ASD!