Embryology

Question 1

What germ layer does the heart derive from?

Answer 1

Visceral Mesoderm (Splanchnic mesoderm) 
The inner lining of the heart, lymphatic and blood vessels, develop from endothelium.

Question 2

What day does the an endocardial tube develop?

Answer 2

Day 19

Question 3

Where does a cardiogenic region start to develop by forming a horseshoe-shaped area?

Answer 3

Splanchnopleuric mesenchyme on either side of the neural plate

Question 4

What are the forerunners of blood cells and vessels?

Answer 4

Formed from cardiac myoblasts and blood islands

Question 5

Foramen secundum is significan for?

Answer 5

Allows shunting of blood from left to right atrium

Question 6

What forms the foramen ovale?

Answer 6

The advanced edge of septum secundum

Question 7

Septum primum function

Answer 7

The septum primum divides the atria into right and left. It acts as a unidirectional flutter valve. Blood only can flow from right atrium to left

Question 8

What gives rise to the aortic arches

Answer 8

Truncus arteriosus

Question 9

Where do progenitor heart cells migrate from?

Answer 9

Progenitor heart cells migrate from ectoderm, down the primitive streak into splanchnic mesoderm. This section is called the primary heart field.

Question 10

What forms the primary heart field?

Answer 10

Left ventricle, atria and part of the right ventricle

Question 11

Where does the rest of the right ventricle derive from?

Answer 11

Secondary heart field consisting of cardiac myoblasts and blood islands

Question 12

What tubes join among themselves when the embryo “folds” laterally

Answer 12

Dorsal aortae and endothelial tubes; fuses on day 22

Question 13

Where does the descending aorta come from?

Answer 13

Dorsal aortae

Question 14

What structure in day 18 does the heart tube form from?

Answer 14

Endothelial tubes

Question 15

What forms from the Sinus venosus

Answer 15

It is incorporated into the wall of the right atrium to form a smooth part called the sinus venarum. The sinus venosus also forms the SA node and the coronary sinus.

Question 16

What are the five regions of the heart rube?

Answer 16

Truncus arteriosus
Bulbus cordis
Ventricle
Atrium
Sinus Venosus

Question 17

What does the truncus arteriosus develop into?

Answer 17

Aorta and pulmonary trunk

Question 18

What does the bulbus cordis develop into?

Answer 18

Trabeculated part of right ventricle, outflow part of both ventricles

Question 19

What does the ventricle develop into?

Answer 19

Trabeculated part of the left ventricle

Question 20

What does the atrium develop into?

Answer 20

Trabeculated part of the both atrium

Question 21

What does the sinus venosus develop into?

Answer 21

Smooth part of right atrium
SA node
Coronary sinus

Question 22

When does the heart start to loop and fold?

Answer 22

Day 23

Question 23

Development of aortic archs

Answer 23

1 and 2 obliterated
3 - Common carotid
4 - Right subclavian 
5 - Rudimentary or absent
6 - Sprout branches that form pulmonary; ductus arteriosus on left

Question 24

Role of the vitelline veins

Answer 24

Drain yolk sac

Question 25

``` Hepatic veins Inferior portion of Inferior vena cava Portal vein Superior mesenteric vein These veins arise from? ```

Answer 25

The viteline vein

Question 26

Role of umbilical veins

Answer 26

Oxygenated blood from placenta into foetus; Right degenerates but left remains as definitive umbilical vein

Question 27

Role of cardinal veins

Answer 27

Give systemic venous system, arise from sinus venosus anteriorly and posteriorly

Question 28

Role of ductus venosus

Answer 28

In the fetus, the ductus venosus shunts a portion of the left umbilical vein blood flow directly to the inferior vena cava. Thus, it allows oxygenated blood from the placenta to bypass the liver.

Question 29

Anterior cardinal veins drain

Answer 29

Head and neck | Go onto become the Jugular system, left brachiocephalic vein and superior vena cava

Question 30

Posterior cardinal veins drain

Answer 30

``` Trunk; go onto become Azygos and Hemiazygos systems (Body wall) Gonadal and Renal veins Iliac veins IVC ```