Embryology (cardiovascular) Flashcards
What is the cardiogenic field?
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.
How does the pericardium form?
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
What are the sections of the primitive heart tube superior to inferior?
Truncus arteriosus
Bulbus cordis
Primitive ventricle
Primitive atrium
Sinus venosus
How does the cardiac loop form?
Bulbis cordis and ventricle enlarged and pushed to right
Then the ventricle is pushed left and inferiority
Atria are pushed superiorly and posteriorly
What does the endocardial cushion do?
Separates the right atrium and ventricle from the left atrium and ventricle to form av canals
What does the primitive ventricle become?
Left ventricle
What does the primitive atrium become?
Parts of right and left atria
What does the sinus venosus become?
Superior vena cava, right atrium
What does the bulbus cordis become?
Right ventricle and parts of outflow tract
What does the aortic sac become?
Aortic arches
What do the semilunar valves form from?
Subendocardial valve tissue
What do the av valves develop from?
Ventricular wall
When does the SA node develop?
Week 5
Before that cardiomyocytes are the pacemakers
What aortic arch forms the common carotid artery?
3rd aortic arch
What aortic arch forms the right subclavian artery?
4th right
What aortic arch forms the aortic arch?
4th left
What forms the right pulmonary artery?
6th right aortic arch
What forms the left pulmonary artery and ductus arteriosus?
6th left arch
What happens to the 1st, 2nd and 5th aortic arches?
They disappear
What causes a double aortic arch?
Non regression of the right aortic arch, which forms a ring around the trachea and oesophagus causing breathing and swallowing difficulty
What causes a PDA?
Maternal rubella early in pregnancy
Muscular wall fails to contract
What do the embryonic vitelline vessels become?
Adult gut vessels
What do the umbilical vessels become?
Internal iliac
When does the lymphatic system develop?
End of week 6
