Embryology of the Heart

Question 1

The heart begins to develop from which embryologic layer

Answer 1

Splanchnic mesoderm

Question 2

Which week does the heart begin to develop

Answer 2

Latter half of week 3

Question 3

Which section of the primitive heart grows more rapidly and folds downward?

Answer 3

Upper truncus arteriosus

Question 4

What is the name of the cranial outflow tract of the primitive heart

Answer 4

Truncus arteriosus

Question 5

How many dilatations does the primitive heart have

Answer 5

Four

Question 6

Name the four dilatations of the primitive heart

Answer 6

Bulbus cordis, primitive ventricle, primitive atrium and sinus venosus

Question 7

Which dilatation of the primitive heart does not become subdivided by a septum

Answer 7

Sinus venosus

Question 8

What are the adult derivatives of the truncus arteriosus

Answer 8

Aorta; Pulmonary trunk; Semilunar values

Question 9

What are the adult derivatives of the bulbus cordis

Answer 9

Smooth part of right ventricle (conus arteriosus)

Smooth part of left ventricle (aortic vestibule)

Question 10

What are the adult derivatives of the primitive ventricle

Answer 10

Trabeculated part of right ventricle

Trabeculated part of left ventricle

Question 11

What are the adult derivatives of the primitive atrium

Answer 11

Trabeculated part of right atrium (pectinate
muscles)
Trabeculated part of left atrium (pectinate
muscles)

Question 12

What are the adult derivatives of the sinus venosus

Answer 12

Right—Smooth part of right atrium (sinus
venarum)
Left—Coronary sinus and oblique vein of left atrium

Question 13

Name the three major venous systems that flow into the sinus venosus

Answer 13

Vitelline (omphalomesenteric) veins, Umbilical vein, Cardinal veins

Question 14

Function of vitelline veins

Answer 14

Drain deoxygenated blood from the

yolk stalk

Question 15

Function of the umbilical vein

Answer 15

carries oxygenated blood from the placenta

Question 16

Function of the cardinal veins

Answer 16

carry deoxygenated blood from the body of the embryo

Question 17

What is the function of the vascular shunts that develop in fetal circulation

Answer 17

to bypass blood flow around the liver and lungs

Question 18

What are the three the vascular shunts that develop in fetal circulation

Answer 18

ductus venosus, foramen ovale, ductus arteriosus

Question 19

The foramen ovale is necessary for which direction of shunting during fetal life

Answer 19

Right to left shunting of blood

Question 20

Closure of right and left umbilical

arteries result in which adult derivative

Answer 20

Medial umbilical ligaments

Question 21

Closure of the umbilical vein results in which adult derivative

Answer 21

Ligamentum teres of liver

Question 22

Closure of ductus venosus results in which adult derivative

Answer 22

Ligamentum venosum

Question 23

Closure of foramen ovale results in which adult derivative

Answer 23

Fossa ovalis

Question 24

Closure of ductus arteriosus result in which adult derivative

Answer 24

Ligamentum arteriosum

Question 25

Atrial septation of the primitive heart begins in which week and ends in which week

Answer 25

Week four and ends in week eight

Question 26

What are the 2 septa and 2 foramina that aids in the division of the primitive atrium

Answer 26

septum primum, foramen primum, foramen secundum and septum secundum

Question 27

Atrial Septal Defects are more common in which gender

Answer 27

Females

Question 28

What are the two clinically important atrial septal defects

Answer 28

the secundum and primum types

Question 29

Of the two clinically important atrial septal defects, which is more common

Answer 29

Secundum-type ASD

Question 30

What causes the Secundum-type ASD

Answer 30

an excessive resorption of the SP or an underdevelopment and reduced size of the SS or both

Question 31

What causes the an excessive resorption of the primum type ASD

Answer 31

a failure of the septum premium to fuse with the endocardial cushions

Question 32

Ventricular septation of the primitive heart begins in which week and ends in which week

Answer 32

begins in week 4 and completed by the end of week 7

Question 33

What are the two parts of the interventricular septum of the primitive heart

Answer 33

muscular and membranous component

Question 34

Which congenital heart defect is the most common

Answer 34

Ventricular septal defect (VSD)

Question 35

Ventricular septal defect (VSD) is most common in which gender

Answer 35

Males

Question 36

Is a membranous or muscular Ventricular septal defect (VSD) more common?

Answer 36

Membranous Ventricular septal defect (VSD)

Question 37

What is the embryoloical cause of membranous Ventricular septal defect (VSD)

Answer 37

failure of neural crest cells to migrate into the endocardial cushions

Question 38

What causes a patent ductus arteriosus

Answer 38

hen the ductus arteriosus (a connection between the pulmonary trunk and aorta) fails to close after birth

Question 39

In what two cases is patent ductus arteriosus common

Answer 39

premature infants and in cases of maternal rubella infection

Question 40

During which week of development does septation of the truncus arteriosus occur

Answer 40

Week eight

Question 41

What is the name of the septum that divides the truncus arteriosus into the aorta and pulmonary trunk

Answer 41

aorticopulmonary (AP) septum

Question 42

What are the three classic cyanotic congenital heart abnormalities

Answer 42

Tetralogy of Fallot, Transposition of the great vessels and Persistent truncus arteriosus

Question 43

Defects in the development of which fetal heart structure results in cyanotic congenital heart abnormalities

Answer 43

aorticopulmonary (AP) septum

Question 44

Which cyanotic congenital heart abnormality is the most common

Answer 44

Tetralogy of Fallot

Question 45

What are the four major defects in the Tetralogy of Fallot

Answer 45

– Pulmonary stenosis – Membranous interventricular septal defect – Right ventricular hypertrophy – Overriding aorta

Question 46

What defect causes tetralogy of Fallot

Answer 46

the AP septum fails to | align properly and shifts anteriorly to the right

Question 47

What defect causes transposition of the great vessels

Answer 47

the AP septum fails to develop in a spiral fashion and results in the aorta arising from the right ventricle and the pulmonary trunk arising from the left ventricle

Question 48

What defect causes truncus arteriosus

Answer 48

when there is only partial development of the AP septum

Question 49

Which aortic arch forms the common carotid arteries and the proximal part of the internal carotid arteries

Answer 49

Aortic arch 3

Question 50

Which aortic arch forms the aortic arch on the left and the brachiocephalic artery and the proximal subclavian artery on the right

Answer 50

Aortic arch 4

Question 51

Which aortic arch forms the proximal pulmonary arteries and ductus arteriosus.

Answer 51

Aortic arch 6

Question 52

What are the 3 branches of the dorsal aorta

Answer 52

Posterolateral Branches, Lateral Branches and ventral branches