Embryology (cardiovascular)

Question 1

What is the cardiogenic field?

Answer 1

In week 3 blood vessels appear in the yolk sac, allantois, connecting stalk and chorion.

Also, vessels in lateral plate splanchnic mesoderm form two heart tubes.

Question 2

How does the pericardium form?

Answer 2

Cranial folding of embryo allows heart tube to lie dorsal to pericardial cavity.
Parietal layer of serous pericardium and fibrous pericardium form from somatic mesoderm.
Visceral layer from splanchnic mesoderm

Question 3

What are the sections of the primitive heart tube superior to inferior?

Answer 3

Truncus arteriosus
Bulbus cordis
Primitive ventricle
Primitive atrium
Sinus venosus

Question 4

How does the cardiac loop form?

Answer 4

Bulbis cordis and ventricle enlarged and pushed to right
Then the ventricle is pushed left and inferiority
Atria are pushed superiorly and posteriorly

Question 5

What does the endocardial cushion do?

Answer 5

Separates the right atrium and ventricle from the left atrium and ventricle to form av canals

Question 6

What does the primitive ventricle become?

Answer 6

Left ventricle

Question 7

What does the primitive atrium become?

Answer 7

Parts of right and left atria

Question 8

What does the sinus venosus become?

Answer 8

Superior vena cava, right atrium

Question 9

What does the bulbus cordis become?

Answer 9

Right ventricle and parts of outflow tract

Question 10

What does the aortic sac become?

Answer 10

Aortic arches

Question 11

What do the semilunar valves form from?

Answer 11

Subendocardial valve tissue

Question 12

What do the av valves develop from?

Answer 12

Ventricular wall

Question 13

When does the SA node develop?

Answer 13

Week 5

Before that cardiomyocytes are the pacemakers

Question 14

What aortic arch forms the common carotid artery?

Answer 14

3rd aortic arch

Question 15

What aortic arch forms the right subclavian artery?

Answer 15

4th right

Question 16

What aortic arch forms the aortic arch?

Answer 16

4th left

Question 17

What forms the right pulmonary artery?

Answer 17

6th right aortic arch

Question 18

What forms the left pulmonary artery and ductus arteriosus?

Answer 18

6th left arch

Question 19

What happens to the 1st, 2nd and 5th aortic arches?

Answer 19

They disappear

Question 20

What causes a double aortic arch?

Answer 20

Non regression of the right aortic arch, which forms a ring around the trachea and oesophagus causing breathing and swallowing difficulty

Question 21

What causes a PDA?

Answer 21

Maternal rubella early in pregnancy
Muscular wall fails to contract

Question 22

What do the embryonic vitelline vessels become?

Answer 22

Adult gut vessels

Question 23

What do the umbilical vessels become?

Answer 23

Internal iliac

Question 24

When does the lymphatic system develop?

Answer 24

End of week 6

Question 25

What does the ductus venosus do?

Answer 25

Connects umbilical vein do IVC allowing oxygenated blood from placenta to bypass liver.

Question 26

What do the Foramen ovale and ductus arteriosus do?

Answer 26

Allow blood to bypass the lungs