Embryology

Question 1

What is angiogenesis/ vasculogenesis?

Answer 1

Formation of new blood vessels from spaces lined by angioplasty

Question 2

What is an angioblast?

Answer 2

Primordia of vascular endothelial cells that form within the mesoderm and spontaneously form blood vessels

Question 3

What is an atrial septal defect?

Answer 3

A hole in the septum that divides the 2 atria

Question 4

Why does an atrial septal defect commonly occur?

Answer 4

The septum secundum fails to completely cover the foramen secundum

Question 5

Bulbus cordis dorms what with the truncus arteriosus?

Answer 5

The outflow tract of the primitive heart tube

Question 6

What are cardinal veins?

Answer 6

System of veins draining the head and body of the developing embryo, joining the sinus venosus

Question 7

What is the cardiogenic region?

Answer 7

The region of mesoderm at the anterior end of the trilaminar disk that will give risk to endocadial tubes

Question 8

What is the conus cordis/ conus arteriosus?

Answer 8

Segment of bulbus cordis that forms the route of the truncus arteriosus

Question 9

What is the Crista terminalis?

Answer 9

Dividing line between smooth walled atrium(sinus venosis) and rough walled atrium (primitive)

Question 10

What is the ductus arteriosis?

Answer 10

The fetal shunt connecting the pulmonary trunk to the aorta to bypass the lungs in utero

Question 11

What’s the ductus venosus?

Answer 11

Fetal shunt directing oxygenated blood carried by umbilical vein from the placenta to inferior vena cava passing the liver

Question 12

What are the endocardial cushions?

Answer 12

4 structures responsible for septation within the heart, loose connective tissue covered by endothelium

Question 13

What forms the primitive heart tube when they fuse during embryonic folding?

Answer 13

Endocardial tube

Question 14

What’s the foramen ovale?

Answer 14

Hole in septum secundum allowing right to left shunt

Question 15

What is a patent ductus arteriosus?

Answer 15

Failure of closure of the ductus arteriosus

Question 16

What is persistent truncus arteriosis?

Answer 16

Failure of the aortic pulmonary septum to form properly. Defect with single arterial trunk

Question 17

Where is the primitive atrium?

Answer 17

Rough walled chamber at the caudal end of primitive heart tube

Question 18

What does the primitive heart tube consist of from inflow to outflow?

Answer 18

Sinus venosus, primitive atrium, primitive ventricle, bulbus cordis, truncus arteriosis

Question 19

What does the primitive ventricle form?

Answer 19

Left ventrcle

Question 20

What is the septum primum?

Answer 20

First membrane to divide primitive atrium.

Question 21

What is the septum secundum?

Answer 21

A muscular infolding of the atrial wall that forms the second membrane dividing the atrium

Question 22

The sinus venosis is the collecting chamber for the primitive heart tube recieving cardinal drainage from the left and right horns. What do the left and right horns become?

Answer 22

Right horn becomes right atrium

Left horn becomes coronary sinus

Question 23

What is tetralogy of fallot? What does it result from?

Answer 23

Result of defective septation of outflow tract

4 defects- Ventricular septal defect, pulmonary stenosis, overriding aorta and RV hypertrophy

Question 24

What is it called when the aorta lies anterior and to the right of the pulmonary trunk?

Answer 24

Transposition of great arteries

Question 25

What is a ventricular septal defect?

Answer 25

Hole between right and left ventricles caused by defect in septation

Question 26

What is the heart tube consisting of at the bottom and top?

Answer 26

Sinus venosus-> aortic roots

Question 27

What is the direction of blood flow at day 28 in vitro

Answer 27

Common atrium-> narrow atrioventricular foramen-> primitive left ventricle-> interventricular foramen-> primitive right ventricle->bulbus cordis (conus cordis to truncus arteriosus)

Question 28

How does the septum of the atrium develop?

Answer 28

Septum primum grows down. Gap at bottom ostium primum, second gap at top Ostium secundum (primum closes) Septum secundum grows down leaving the fossa ovales Failure leads to atrial septal defect

Question 29

How does the interventricular septum form?

Answer 29

Muscular septum grows bottom up Endocardial cushion grows from the side Membranous interventicular septum grows down

Question 30

What will failure of the membranous portion of the interventricular septum result in?

Answer 30

Ventricular septal defect

Question 31

What does the spiral septum divide in development

Answer 31

Pulm tract and aorta | Failure leads to transposition of great vessels

Question 32

What is the inter-uterine blood flow once development of heart has taken place?

Answer 32

RA->Foramen ovale-> LA->LV->system circ | LV->ductus arteriosus-> System circ

Question 33

What happens to the ductus arteriosus after birth

Answer 33

Closes to leave the ligamentum arteriosum