Heart Embryology

Question 1

Types of folding in early development

Answer 1

• Lateral folding

- Cranio-caudal folding

Question 2

Cranio caudal folding of heart development

Answer 2

-Repositioning of the cardiogenic region from the cranial rim to the thorax

Question 3

Lateral folding

Answer 3

leads to merging of the endocardial tubes which leads to development of the primitive heart tube

Question 4

Embryo: Aortic arches

Answer 4

Adult: Cranial/Thoracic arteries

Question 5

Embryo: Truncus arteriosus

Answer 5

Adult: Distal OFT

Question 6

Embryo: Bulbus cordis

Answer 6

Adult: Proximal OFT

Question 7

Embryo: Primitive ventrical

Answer 7

Right ventricle

Left ventrical

Question 8

Primitive atrium

Answer 8

R Atrium

L Atrium

Question 9

Sinus venosus

Answer 9

Coronary sinus

Question 10

Cardinal, umbilical, vitelline veins

Answer 10

Vena cava veins

Question 11

Formation of cardiac loop

Answer 11

The heart tube elongates and loops ventrally

Question 12

Heart looping

Answer 12

Cranial aspect bends to the right (ventro-caudally)
Caudal aspect bends to the left (dorso-cranially)
Ventricle- caudally and right
Atrium- cranially and left
Major transition: cranial caudal to transverse right to left

Question 13

Septation of the heart chambers and OFT

Answer 13

1. Atrial septation
2. Ventricular
3. A-V canal
4. OFT septation (pulmonary from aorta)

Question 14

Endocardial cushions

Answer 14

Epithelial to mesenchymal transition

Question 15

All layers of heart tube come from:

Answer 15

Splanchnic mesoderm

Question 16

Atrial septation

Answer 16

• 2 walls –> foramen ovale
• Ostrium secundum: second hole
• first wall –> first hole –> second hole –> second wall
• second hole is located in the first wall

Question 17

patent foramen ovale

Answer 17

the two septae fail to close allowing continued shunting of blood from the right atrium to the left atrium after birth, eventually left to right atrium

Question 18

Name of the second hole in the developing atrial septum and where is it located

Answer 18

Ostium secundum within the septum primum

Question 19

Ventricular septation

Answer 19

Inter ventricular septum : muscular, from apex of the ventricular myocardium
Inter-ventricular foramen: while we wait for AV canal and OFT to septate
Inter-ventricular septum: membranous, from endocardial cushions of AV canal and OFT

Question 20

AV Canal Septation

Answer 20

Shared AV canal–> Left and Right AV canals (looping) –> Involves AV looping

Question 21

OFT septation (out flow tract)

Answer 21

Involves endocardial cushions
Spiral Septum in order to get P.V. from RV and A. V. from the LV
(Linear septum = parallel septum and RV goes to aorta and LV to pulmonary trunk)

Question 22

Closing the IV foramen

Answer 22

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Question 23

3rd aortic arches

Answer 23

Give rise to L and R common carotid arteries

Question 24

4th aortic arch

Answer 24

Gives rise to R subclavian artery and the aorta

Question 25

6th aortic arch

Answer 25

Gives rise to pulmonary trunk and the ductus arteriosus

Question 26

Left subclavian

Answer 26

contributed by 7th segmental artery

NOT AORTIC ARCH

Question 27

Asymmetric remodeling of aortic arches

Answer 27

3rd aortic arch detaches to become common carotid artery

• degeneration of the LR dorsal aortae
• segregates blood going to the head from blood going to the trunk