Lecture 5

Question 1

What is a congenital heart defect?

Answer 1

structural abnormalities of the heart present from birth. They affect blood flow through the heart and to the rest of the body.

Question 2

How many babies are born with some kind of congenital heart defect?

Answer 2

1 in 100

Question 3

How many CHD are chromosomal?

Answer 3

16%

Question 4

How many CHD are from maternal diabetes?

Answer 4

2%

Question 5

How many CHD are from syndromes?

Answer 5

2%

Question 6

How many CHD are from unknown environmental factors?

Answer 6

80%

Question 7

What is the first organ in the body to develop?

Answer 7

The heart

Question 8

What is the thick layer of cardiac muscle in the heart called?

Answer 8

Myocardium

Question 9

What are the individual cells that make up the myocardium called?

Answer 9

Cardiomyocytes

Question 10

What is the endothelial layer that lines the inside of the heart called?

Answer 10

The endocardium

Question 11

What does the endocardium give rise to?

Answer 11

The endocardial cushions which are precursors of the valves and membranous septa.

Question 12

What cells are essential components of the outflow tract cushions?

Answer 12

Neural crest cells

Question 13

What are the great arteries coated in?

Answer 13

Smooth muscle cells

Question 14

What is the single layer of epithelial cells lining the heart called?

Answer 14

Epicardium

Question 15

What is the whole heart enclosed in?

Answer 15

The pericardium.

Question 16

How long is the embryonic stage of development and what occurs?

Answer 16

8 weeks. Many differentiation and formation of the different organs. Differentiation of cells.

Question 17

How long is the foetal stage of development and what occurs?

Answer 17

Last 32 weeks of pregnancy. Mainly growth of the foetus.

Question 18

What are the three distinct layers that form during gastrulation?

Answer 18

Ectoderm, mesoderm and endoderm

Question 19

What does the ectoderm fold into?

Answer 19

The neural tube (brain and spinal cord)

Question 20

What two distinct regions does the mesoderm become?

Answer 20

Splenic mesoderm and the pre-myocardium

Question 21

What do the two types of mesoderm form?

Answer 21

The cardiac crescent

Question 22

What are the two fields of cell types that form the hear?

Answer 22

Primary and secondary heart fields

Question 23

What do cells from the primary heart field become?

Answer 23

The left ventricle and some atria

Question 24

What do cells from the secondary heart field become?

Answer 24

The right ventricle, outflow tract and most atria.

Question 25

What are the two types of foetal shunts?

Answer 25

Arterial duct and foreman ovale

Question 26

What type of shunt is the arterial duct?

Answer 26

Right to left

Question 27

Where is the foreman ovale?

Answer 27

Between the atria. It is also a right-to-left shunt.

Question 28

In what CHD is keeping the arterial duct open beneficial?

Answer 28

Transposition of the great arteries.

Question 29

What is produced during pregnancy to keep the arterial duct open?

Answer 29

Prostaglandins PGE1 and PGE2

Question 30

What receptors do the prostaglandins act on?

Answer 30

EP2 and EP4

Question 31

Which prostaglandin and receptor pair is major in induced AD dilation?

Answer 31

PGE2 and EP4. Levels of their expression go down after birth to close the duct.

Question 32

What are the three types of intracardiac malformations?

Answer 32

ASD, VSD and tetralogy of Fallot

Question 33

What type of shunt is VSD and ASD?

Answer 33

left-to-right

Question 34

What three things is occurring in tetralogy of Fallot?

Answer 34

VSD, overriding aorta and pulmonary stenosis. Causes a right to left shunt.

Question 35

What is a symptom of ToF?

Answer 35

Blue colour/cyanosis from right-to-left shunt

Question 36

What are the valves derived from?

Answer 36

endocardial cushions

Question 37

Where do cardiac neural crest cells stem from?

Answer 37

The cranial portion of the neural tube

Question 38

Where do cardiac neural crest cells migrate through?

Answer 38

Pharyngeal arches 3, 4 and 6 to form the outflow tract, valves and arteries.

Question 39

What are three types of outflow tract malformations?

Answer 39

Transposition of great arteries, double-outlet right ventricle and common arterial trunk

Question 40

Which is most severe?

Answer 40

CAT

Question 41

What other defect does DORV have to come with or it would be fatal?

Answer 41

VSD

Question 42

Which process does not occur properly in DORV?

Answer 42

twisting

Question 43

What is CAT?

Answer 43

Common arterial trunk. septation does not occur so there is just one outflow tract.

Question 44

How many cusps does each valve have?

Answer 44

mitral valve is bicuspid, all rest are tricuspid (aortic, pulmonary and right AV valve)

Question 45

What is hypoplastic left ventricle syndrome?

Answer 45

Narrowed aorta and very small left ventricle

Question 46

What mutation is present in 65% of people with charge syndrome?

Answer 46

CHD7 on chromosome 8

Question 47

In down syndrome, what are the more common heart defects?

Answer 47

AV septal defects or VSD. 5% have tetralogy of Fallot.

Question 48

What gene defect is associated with Holt Oram syndrome?

Answer 48

TBX5