Embryology

Question 1

What germ layer is the heart derived from?

Answer 1

Visceral mesoderm

Question 2

What brings the developing heart into its final location in the thorax?

Answer 2

Embryonic folding

Question 3

What are the names of the different regions of the heart tube?

Answer 3

Truncus arteriosus (cranial)
Bulbus cordis
Ventricle 
Atrium
Sinus venosus (caudal)

Question 4

What does the truncus arteriosus give rise to in the adult heart?

Answer 4

Aorta and pulmonary trunk

Question 5

What does the bulbus cordis give rise to in the adult heart?

Answer 5

Trabeculated part of the right ventricle

Outflow part of both ventricles

Question 6

What does the ventricle give rise to in the adult heart?

Answer 6

Trabeculated part of the left ventricle

Question 7

What does the atrium give rise to in the adult heart?

Answer 7

Trabeculated part of both atria

Question 8

What does the sinus venosus give rise to in the adult heart?

Answer 8

Smooth part of the right atrium and the coronary sinus

Question 9

Describe the movements that occur during looping and folding of the heart tube

Answer 9

Atrium moves dorsal and cranial
Ventricle is displaced left
The bulbus cordis moves inferiorly and ventrally to the right

Question 10

What are the key steps in the formation of the septa of the heart?

Answer 10

The septum primum and the septum secundum are pushed together and the communication between the atria is lost

Question 11

Name the blood vessels that empty into the sinus venosus

Answer 11

Common cardinal vein
Left umbilical vein
Right vitelline vein

Question 12

How do the blood vessels change as the sinus venosus develops?

Answer 12

A venous system develops in the heart and there is a shift in blood flow towards the right
Veins are lost from the left side
and both umbilical veins are lost

Question 13

What are the venous origins of the smooth parts of the right and left atria?

Answer 13

???

Question 14

How do the pulmonary veins form?

Answer 14

They aprout from the wall of the left ventricle. As the atrium expands, the proximal part of the pulmonary veins is adsorbed into the wall of the left atrium.

Question 15

How many aorta are in the embryo?

Answer 15

Two, run parallel to each other

Question 16

What happens to arches 1 and 2 of the aorta?

Answer 16

They are mostly obliterated

Question 17

What happens to arch 3 of the aorta?

Answer 17

It is an asymmetrical arch
Common carotid artery
First part of the internal carotid artery

Question 18

What does arch 4 of the aorta become?

Answer 18

The right subclavian artery and a part of the aortic arch

Question 19

What happens to arch 5?

Answer 19

It is undeveloped or absent

Question 20

What happens to arch 6?

Answer 20

It sprouts branches that form pulmonary arteries and ductus arteriosus on the left

Question 21

`Name the 3 venous systems found in the embryo

Answer 21

Vitelline veins
Umbilical veins
Cardinal veins

Question 22

What changes occur in the circulatory system at birth?

Answer 22

The atrial septum closes resulting in blood being separated on the right and left side. The heart gets a oxygenated and deoxygenated side.