CVS: Development Of The Heart

Question 1

What is septation?

Answer 1

How the heart divides into sections.

Question 2

What are the 2 types of septation that occurs in the heart?

Answer 2

1. Inter-atrial septum

2. Inter-ventricular septum

Question 3

Name 3 fetal shunts.

Answer 3

1. Ductus Venosus
2. Foramen Ovale
3. Ductus Arteriosus

Question 4

What is the ductus Venosus?

Answer 4

The shunt between the placenta and the inferior vena cava in fetus’.

Question 5

What is the foramen ovale?

Answer 5

The shunt between the right and left atria.

Question 6

What is the ductus arteriosus?

Answer 6

The shunt between the pulmonary trunk and the aorta.

Question 7

Why does the foramen ovale close at birth?

Answer 7

The pressure in the left atria increases which causes it to close.

Question 8

How does the ductus arteriosus close at birth?

Answer 8

Muscular contractions

Question 9

Name the 6 sections of the primitive heart tube.

Answer 9

1. Aortic roots
2. Truncus arteriosus
3. Bulbous cordis
4. Ventricle
5. Artium
6. Sinus venosus

Question 10

How is the primitive heart tube formed?

Answer 10

Two endocardial tubes urge to form the primitive heart tube

Question 11

Why does the primitive heart tube loop during development?

Answer 11

As the tube elongates it runs out of room in the pericardial sack and therefore twists and folds up.

Question 12

Describe the development of the great vessels.

Answer 12

Endocardial cushions appear in the trunchus arteriosis. They twist as they grow forming a spiral septum.

Question 13

From which of the vessels, of the early bilaterally symmetrical arterial system, does the arch of the aorta originate?

Answer 13

The left 4th vessel

Question 14

From which of the vessels, of the early bilaterally symmetrical arterial system, does the arch of the pulmonary originate?

Answer 14

6th arch

R= R pulmonary artery 
L= L pulmonary artery and ductus arteriosus

Question 15

From which of the vessels, of the early bilaterally symmetrical arterial system, does the arch of the subclavian artery originate?

Answer 15

Proximal part of right 4th arch

Question 16

What is the name of the first septum produced separating the right and left atrium?

Answer 16

The septum primum

Question 17

What is the name of the second septum produced separating the right and left atrium?

Answer 17

The septum secundum

Question 18

What is atrial septal defect?

Answer 18

A congenital heart defect in which the blood flows between the atria as there is a malformed septum.

Question 19

What is Hypoplastic left heart syndrome?

Answer 19

Either when there is a defect in the mitral or aortic valve resulting in limited blood flow, or osmium secundum is too small meaning in utero the left heart isn’t used so is under developed.

Question 20

Name the 2 components of ventricular septum.

Answer 20

1. Muscular (forms most of the septum an grows upwards towards the fused endocardial cushions)
2. Membranous (derived from endocardial cushions)

Question 21

Which is more common, ventricular or atrial septal defects?

Answer 21

Ventricular (due to the fact there is a membranous portion to the septum involved)

Question 22

What is transposition of the great arteries?

Answer 22

When the aorta arises from the right ventricle and the pulmonary trunk arises from the left ventricle (worn way around)!!

Question 23

What is tetralogy of Fallot?

Answer 23

A congenital condition characterised by the presence of 4 structural defects.

Question 24

What are the 4 structural defects associated with tetralogy of Fallot?

Answer 24

1. Large ventricular septal defect
2. Overriding aorta
3. Pulmonary stenosis
4. RV hypertrophy

Question 25

Define a cyanotic heart defect.

Answer 25

A group of congenital hear defects that occur due to deoxygenated blood bypassing the lungs and entering systemic circulation.